Common Cold

Definitions

Common Cold is a Typically Benign and Self-Limited Viral Upper Respiratory Tract Infection

Epidemiology

Incidence of the Common Cold

  • Common Cold is the Most Frequent Acute Illness in the United States and in the Industrialized World (Prim Care, 1996) [MEDLINE]
    • Preschool Children Have an Average Incidence of 5-7 Common Cold Episodes Per Year (Epidemiol Rev, 1994) [MEDLINE]
      • Absences from School Amount to 26 Million Days Annually (Allergy Asthma Immunol, 1997) [MEDLINE]
    • Adults Have an Average Incidence of 2-3 Common Cold Episodes Per Year (Epidemiol Rev, 1994) [MEDLINE]
      • Absences from School Amount to 23 Million Days Annually (Allergy Asthma Immunol, 1997) [MEDLINE]

Economic Burden of the Common Cold

  • Common Cold is Associated with a Significant Loss of Work Productivity and Substantial Medical Expenditures (Ann Allergy Asthma Immunol, 1997) [MEDLINE]
  • Approximately 500 Million Non-Influenza Viral Respiratory Illnesses were Reported (Between 2000-2001) (Arch Intern Med, 2003) [MEDLINE]
    • Accounted for Direct Costs of $17 Billion Annually
    • Accounted for Indirect Costs of $22.5 Billion Annually

Seasonal Variation in Incidence of the Common Cold

Location-Based Variation in Incidence of the Common Cold

  • Adenovirus Outbreaks Have Been Reported in Daycare Centers, Hospital Wards, and Military Facilities
    • Notably, Adenovirus Infections are Not Typically Seasonal

Risk Factors

Risk Factors for Common Cold

  • Exposure to Children in Daycare Settings (Epidemiol Rev, 1994) [MEDLINE]
  • Psychological Stress (NEJM, 1991) [MEDLINE]
  • Sleep Disturbance/Less Sleep (see Insomnia) (Arch Intern Med, 2009) [MEDLINE]

Protective Factors Against the Common Cold

  • Moderate Physical Exercise (Med Sci Sports Exerc, 1994) [MEDLINE]

No Impact on Risk of Common Cold

  • Cold Climate

Risk Factors for More Severe Upper Respiratory Tract Infection

  • Chronic Disease
  • Congenital Immunodeficiency Disorder
  • Malnutrition (see Malnutrition)
  • Tobacco Abuse (see Tobacco)

Etiology

General Comments

  • Approximately 200 Viruses are Associated with the Common Cold
  • During a Single Season, a Single Antigenic Type of Virus Accounts for Only <1% of Colds
  • It is Generally Not Possible to Determine the Viral Pathogen Based on the Clinical Symptoms, as All of the Viral Etiologies May Result in Similar Symptoms (Epidemiol Infect, 1993) [MEDLINE]
  • Most of the Respiratory Viruses Which Cause the Common Colds are Capable of Reinfection after Reexposure (Prim Care, 1996) [MEDLINE]
    • However, Subsequent Infections with the Same (or Similar) Virus are Clinically Milder and of Shorter Duration (J Clin Invest, 1959) [MEDLINE]
    • The Molecular Mechanism for Incomplete Immunity Following Infection with One Common Cold Virus Strain is Not Well-Understood, But Data from Rhinoviruses Suggest that it May Involve the Significant Degree of Structural and Molecular Variability within Serotypes and Between Divergent Strains Which Result from Mutation of a Given Reference Virus Strain (Science, 2009) [MEDLINE] PICTURE

Viral Etiologies

  • Adenoviruses (see Adenoviruses)
    • In Humans, There are Approximately 88 Adenoviruses in 7 Different Species (Species A-G)
      • Respiratory Disease is Predominantly Associated with Species HAdV-B and HAdV-C
    • Adenoviruses Account for <5% of Common Cold Cases
    • Adenovirus More Commonly Presents with Pharyngitis and Fever than Common Cold Symptoms
    • Adenovirus May Also Cause Lower Respiratory Tract Infections in Military Recruits
    • Adenovirus May Also Cause Severe Lower Respiratory Tract Infections in Immunocompromised Patients
  • Bocaviruses (see Bocaviruses)
    • Bocaviruses are Members of Parvovirus (Parvoviridae) Family (see Parvoviruses)
    • Human Bocavirus 1 (1HBoV1) was Discovered in 2005
      • HBoV1 is Associated with Respiratory Disease in Children (Common Cold, Acute Otitis Media, Pneumonia, Bronchiolitis, and Asthma Exacerbation) (Lancet Child Adolesc Health, 2019) [MEDLINE]
    • Other Bocaviruses were Subsequently Discovered in 2009-2010
  • Coronaviruses (see Coronaviruses)
    • Coronaviruses Account for 10-15% of Common Cold Cases
  • Enteroviruses (Coxsackie Virus, Echovirus, and Other Enteroviruses) (see Enteroviruses, Coxsackie Virus, and Echovirus)
    • Enteroviruses Account for <5% of Common Cold Cases
    • Enteroviruses More Commonly Present with a Febrile Illness
    • Enteroviruses Can Also Cause Aseptic Meningitis and Pleuritis
  • Human Metapneumovirus (see Metapneumovirus)
    • Human Metapneumovirus Accounts for Unclear Percentage of Common Cold Cases
  • Influenza Virus (see Influenza Virus)
    • Influenza Virus Accounts for 5-15% of Common Cold Cases)
    • Generally Cause More Systemic Symptoms than Other Common Cold Viruses, But Some Cases May Present as the Common Cold
  • Parainfluenza Virus (see Parainfluenza Virus)
    • Parainfluenza Virus Accounts for 5% of Common Cold Cases
    • Generally Cause More Systemic Symptoms than Other Common Cold Viruses, But Some Cases May Present as the Common Cold (Especially in Young Children)
  • Respiratory Syncytial Virus (RSV) (see Respiratory Syncytial Virus)
    • Respiratory Syncytial Virus Accounts for 5% of Common Cold Cases
    • However, Some Cases May Present as the Common Cold (Especially in Young Children)
  • Rhinovirus (see Rhinovirus)
    • Most Common Etiology of the Common Cold
    • Rhinovirus Accounts for 30-50% of Common Cold Cases
    • There are >100 Serotypes of Rhinoviruses
  • Undiscovered Viruses
    • Account for 20-3% of Common Cold Cases

Physiology

Mechanisms of Transmission (Ann Allergy Asthma Immunol, 1997) [MEDLINE] (J Antimicrob Chemother, 2005)[MEDLINE]

  • Small Particle Droplets (Droplet Nuclei or Aerosols) Which Become Airborne Via Coughing or Sneezing
  • Large Particle Droplets (Classic Droplet Transmission) Which Require Close Contact with an Infected Person
  • Hand Contact (Via COntact with an Infected Person or Via Indirect Contact with a Contaminated Surface

Virus Viability

  • Common Cold Viruses Remain Viable on the Surface of the Skin for Up to 2 hrs
  • Rhinovirus Remains Viable on Environmental Surfaces for Several Hours
    • Porous Materials (Tissues, Cotton Handkerchiefs) are Poor Substrates for Viral Survival and, Therefore, are Inefficient Modes of Common Cold Viral Transmission
    • Decontamination of Surfaces with Virucidal Disinfectants (Phenol, Alcohol, etc) Decrease the Risk of Common Cold Viral Transmission
    • Unsurprisingly, Use of Antibacterial Home Cleaning Products Did Not Impact the Incidence of Respiratory Symptoms in Study Patients, as Compared to Standard Cleaning Products (Ann Intern Med, 2004) [MEDLINE]
  • Saliva is a Poor Mode of Common Cold Viral Transmission, as >90% of Patients with Common Cold Have No Detectable Virus in Their Saliva (Prim Care, 1996) [MEDLINE]

Impact of Airplane Air Recirculation on Incidence of the Common Cold

  • Aircraft Cabin Air Recirculation Did Not Increase the Risk of Upper Respiratory Tract Symptoms in Passengers Traveling on Commercial Jet Airplanes (JAMA, 2002) [MEDLINE]

Period of Infectivity

  • With Rhinovirus, Peak Viral Shedding Occurs on the 2nd Day of Illness (Am Rev Respir Dis, 1966) [MEDLINE] (J Clin Virol, 2004) [MEDLINE]
    • Peak Viral Shedding Occurs on the 3rd Day of the Illness After Inoculation (This is the Period of Peak Symptoms)
    • Lower Levels of Viral Shedding May Persist for as Long as 2 wks
  • Period of Viral Shedding Does Not Correlate with the Period of Clinical Disease
    • In Rhinovirus Infection, Asymptomatic Viral Shedding is Common
      • Positive Rhinovirus PCR Has Been Reported in 6% of Asymptomatic Adults and 35% of Asymptomatic Children at Any Given Point in Time (mSphere, 2018) [MEDLINE] (Pediatrics, 2014) [MEDLINE] (J Infect Dis, 2018) [MEDLINE]

Diagnosis

Multiplexed Nucleic Acid Respiratory Pathogen Panel (see xxxx)

General Comments

  • Note that in Rhinovirus Infection, Asymptomatic Viral Shedding is Common, Making Multiplex Testing of Unclear Utility (Since No Specific Therapy is Available, Regardless)
    • Positive Rhinovirus PCR Has Been Reported in 6% of Asymptomatic Adults and 35% of Asymptomatic Children at Any Given Point in Time (mSphere, 2018) [MEDLINE] (Pediatrics, 2014) [MEDLINE] (J Infect Dis, 2018) [MEDLINE]

BioFire Panel (Biomérieux)

Nasal Bacterial Culture

  • Nasal Bacterial Cultures are Not Recommended For Evaluation of the Common Cold
    • Study of Nasal Bacterial Cultures (Nasal Aspirate) in Patients with Common Cold (Lancet, 1996) [MEDLINE]
      • Only 61 Out of 300 Patients Had Nasal Bacterial Cultures Positive for Potential Pathogens (Haemophilus Influenzae, Moraxella Catarrhalis, or Streptococcus Pneumoniae)
        • In Terms of Symptom Scores, Antibiotic Therapy (Amoxicillin-Clavulanate) Benefited Patients Only in This Group

Serum Procalcitonin (see Serum Procalcitonin)

General Comments

  • While Not Standardly Used, Serum Procalcitonin May Help Avoid Unneccesary Antibiotic Exposure in the Outpatient Management of Upper Respiratory Tract Infections

Clinical Efficacy

  • Procalcitonin Use Decreased Antibiotic Use in the Treatment of Respiratory Tract Infections the Primary Care Setting (Arch Intern Med, 2008) [MEDLINE] (Clin Chem Lab Med, 2017) [MEDLINE]

Clinical Differentiation of Upper Respiratory Tract Infection vs Lower Respiratory Tract Infection

Clinical Manifestations

General Comments

Incubation Period

  • Incubation Period: 24-72 hrs
    • However, in Experimental Settings, Incubation Periods as Short as 10-12 hrs Have Been Observed (Lancet, 2003) [MEDLINE]

Clinical Course

  • Symptoms Increase Rapidly (Peaking 2-3 Days After Infection) (Lancet Infect Dis, 2005) [MEDLINE]
  • Symptoms of the Common Cold are Generally Due to the Immune Response to Infection, Rather than Direct Viral Damage to the Respiratory Tract
    • In Contrast, Influenza Virus Causes Damage to Respiratory Epithelium (see Influenza Virus) (J Virol, 2018) [MEDLINE]
    • Intensity and Type of Clinical Symptoms of the Common Cold May Be Related to the Type of infecting Virus and Host Factors (Including Age, Underlying Illness, and Prior Immunological Experience) (Lancet Infect Dis, 2005) [MEDLINE]
      • Consequently, Upper Respiratory Tract Infections May Be Asymptomatic, May Be Associated with an Acute Self-Limiting Illness, or May Be Lethal

Upper Respiratory Tract Infection Clinical Scoring Systems (Eur Respir J, 2006) [MEDLINE]

  • Jackson Cold Scale (AMA Arch Intern Med, 1958) [MEDLINE]
    • Sensitivity: 81%
    • Specificity: 66%
  • Wisconsin Upper Respiratory Symptom Survey (WURSS) (Health Qual Life Outcomes, 2009) [MEDLINE]
    • Sensitivity: 85%
    • Specificity: 44%

Duration of Illness

  • Duration of Illness (Normal Host): 3-10 days (Prim Care, 1996) [MEDLINE] (Lancet, 2003) [MEDLINE]
    • Duration of Illness May Be as Long as 2-3 wks in Up to 25% of Patients (Particularly Smokers) (Ann Allergy Asthma Immunol, 1997) [MEDLINE] (Lancet Infect Dis, 2005) [MEDLINE]

Neurologic Manifestations

  • Headache (see Headache)
    • Epidemiology
      • Headache is Common (Occurs Early in Course) (Arch Intern Med, 1958) [MEDLINE] (Lancet Infect Dis, 2005) [MEDLINE]

Ophthalmologic Manifestations

Otolaryngologic Manifestations

  • Anosmia (see Anosmia)
    • Epidemiology
      • Anosmia is Common the Common Cold, as Well as in SARS-CoV-2 (Although Different Mechanisms May Be Responsible) (Rhinology, 2020) [MEDLINE]
  • Eustachian Tube Dysfunction (see Eustachian Tube Dysfunction)
    • Epidemiology
      • Eustachian Tube Dysfunction is Frequently Associated
  • Hoarseness (see Hoarseness)
    • Epidemiology
      • Hoarseness May Occur in Some Cases
  • Nasal Congestion/Obstruction (see Nasal Congestion)
    • Epidemiology
      • Common (Occurs Later in Course) (Arch Intern Med, 1958) [MEDLINE] (Lancet Infect Dis, 2005) [MEDLINE]
      • Nasal Congestion/Obstruction Increases in Severity Over the First Week of Symptoms (Arch Intern Med, 1958) [MEDLINE]
    • Physiology
      • Due to Dilation of the Large Veins in the Nasal Epithelium (Venous Sinuses) in Response to the Vasodilator Mediators of Inflammation (Bradykinin, etc) (Lancet Infect Dis, 2005) [MEDLINE]
    • Clinical
      • Nasal Mucosal Edema
  • Pharyngitis/Sore Throat (see Pharyngitis)
    • Epidemiology
      • Pharyngitis is Common (Occurs Early in Course) (Arch Intern Med, 1958) [MEDLINE] (Lancet Infect Dis, 2005) [MEDLINE]
      • Scratchy Sensation or Throat Irritation is Often the First Symptom of an Upper Respiratory Tract Infection (Such as the Common Cold)
        • May Be Related to Early Viral Infection of the Nasopharynx, Rather than the Nasal Epithelium (Lancet Infect Dis, 2005) [MEDLINE]
    • Clinical
      • Pharyngeal Erythema
      • Absent/Minimal Cervical Lymphadenopathy (see Lymphadenopathy)
  • Rhinitis (see Rhinitis)
    • Epidemiology
      • Rhinitis is Common
  • Rhinorrhea/Nasal Discharge (see Rhinorrhea and Nasal Discharge)
    • Epidemiology
      • Rhinorrhea/Nasal Discharge is Common (Occurs Later in Course) (Arch Intern Med, 1958) [MEDLINE] (Lancet Infect Dis, 2005) [MEDLINE]
    • Clinical
      • Nasal Discharge May Be Clear or Purulent
        • Although Clinicians Commonly Use the Presence of Purulence to Determine if Antibiotics are Required (for a Sinus Infection), its Presence Alone Does Not Distinguish Between the Common Cold and a Sinus Infection (Lancet, 1997) [MEDLINE]
  • Sinus Pain/Pressure (see Sinus Pain)
    • Physiology
      • Due to Pressure Changes in the Sinus Air Space and Pressure Changes in the Blood Vessels Draining the Sinus
      • Sinuses with Patent Ostia May Also Be Painful (Due to Inflammatory Mediators within the Sinus)
    • Diagnosis
      • Sinus CT Scan (see Sinus Computed Tomography)
        • In a Sinus CT Study of Rhinovirus-Associated Common Cold, Sinus Abnormalities were Common (87% of Cases Demonstrated Abnormalities of One or Both Maxillary Sinus Cavities, 65% of Cases Demonstrated Abnormalities of the Ethmoid Sinuses, 32% of Cases Demonstrated Abnormalities of the Frontal Sinuses) (NEJM, 1944) [MEDLINE]
        • However, Since Asymptomatic Patients May Demonstrate Radiographic Abnormalities on Sinus X-Rays/CT, These Studies are Not Routinely Recommended in the Evaluation of the Common Cold (Arch Otolaryngol Head Neck Surg, 1988) [MEDLINE] (Laryngoscope, 1991) [MEDLINE]
    • Clinical
      • True Symptomatic Sinusitis is Uncommon (Although Sinus Mucosal Thickening Can Often Be Demonstrated on Sinus CT Scan)
      • In Contrast to the Common Cold, Acute Rhinosinusitis Presents with Facial Pain and Purulent Nasal Discharge (see Acute Rhinosinusitis)
  • Sneezing (see Sneezing)
    • Epidemiology
      • Sneezing is Common (Occurs Early in Course) (Arch Intern Med, 1958) [MEDLINE] (Lancet Infect Dis, 2005) [MEDLINE]
    • Physiology
      • Sneezing is Mediated by the Trigeminal Nerve (Which Supplies the Nasal Epithelium and the Anterior Region of the Nasopharynx with Sensory Fibers) (Lancet Infect Dis, 2005) [MEDLINE]
  • Vertigo/Viral Labyrinthitis (see Labyrinthitis)
    • Epidemiology
      • May Occur in Some Cases

Pulmonary Manifestations

  • Cough (see Cough)
    • Epidemiology
      • Common (Occurs Later in Course After the Onset of Nasal Obstruction/Discharge) (Arch Intern Med, 1958) [MEDLINE] (Lancet Infect Dis, 2005) [MEDLINE]
    • Physiology
      • Regarding the General Mechanism of Cough, it is Mediated Via the Vagus Nerve (Cough is Initiated by Airway by Stimulation of Sensory Nerves at the Level of the Larynx or Below) (Lancet Infect Dis, 2005) [MEDLINE]
      • Common Cold Viruses Usually Do Not Cause Any Significant Damage to the Airway Epithelium, Such that the Common Cold Often Occurs with Little, if Any, Cough (Acta Otolaryngol Suppl, 1984) [MEDLINE]
      • In Contrast, Influenza May Cause Significant Respiratory Epithelial Damage, Such that Influenza Infection is Usually Associated with Cough (Lancet Infect Dis, 2005) [MEDLINE]
    • Clinical
      • Normal Lung Exam (Unless Bronchospasm is Present)
      • Cough is Less Prominent that in Influenza (for the Above Reason Related to Lack of Damage to the Airway Epithelium)
      • When Present, Cough May Persist for Weeks After the Resolution of Other Clinical Symptoms (Such as Nasal Obstruction and Sore Throat) (Ann Fam Med, 2013) [MEDLINE]

Rheumatologic Manifestations

  • Myalgias (see Myalgias)
    • Epidemiology
      • Occur in 50% of Upper Respiratory Tract Infections (Pain Med, 2003) [MEDLINE]
    • Physiology
      • Likely Due to Effects of Cytokines on Skeletal Muscle

Other Manifestations

  • Chills
    • Epidemiology
      • Common (Occurs Early in Course) (Arch Intern Med, 1958) [MEDLINE] (Lancet Infect Dis, 2005) [MEDLINE]
  • Fever (see Fever)
    • Epidemiology
      • Fever is Uncommon in Adults with the Common Cold
        • Transient Hypothermia May Occur During the Early Phase of the Common Cold (Arch Intern Med, 1958) [MEDLINE]
      • Fever May Occur in Children with the Common Cold
    • Clinical
      • In Contrast to the Common Cold, Influenza Generally Presents with High Fever, Headache, Cough, and Myalgias (see Influenza Virus)
  • Malaise
    • Epidemiology
      • Common (Occurs Later in Course) (Lancet Infect Dis, 2005) [MEDLINE]

Complications of the Common Cold

  • Acute Otitis Media (see Acute Otitis Media)
    • Viral Upper Respiratory Tract Infection Frequently Causes iEustachian Tube Dysfunction with Resulting Impaired Clearance and Pressure Dysregulation in the Middle Ear, Which May Predispose to the Development of Acute Otitis Media (Particularly in Children) (Lancet, 2004) [MEDLINE]
  • Acute Rhinosinusitis (see Acute Rhinosinusitis)
    • Viral Rhinosinusitis Occurs Far More Commonly than Frequently than Secondary Bacterial Rhinosinusitis
      • However, the Latter May Occur in Some Cases
  • Asthma Exacerbation (see Asthma)
    • Viral Upper Respiratory Tract Infection Has Been Associated with Up to 40% of Acute Asthma Exacerbations in Adults (Chest, 1997) [MEDLINE] (J Infect Dis, 2007) [MEDLINE]
    • Rhinovirus is the Common Cold Virus Most Associated with Asthma Exacerbation
      • In Addition, Rhinovirus-Induced Changes in Airway Reactivity May Persist for Up to 4 wks After Infection (Am J Respir Crit Care Med, 1995) [MEDLINE]
  • Lower Respiratory Tract Disease
    • Most Patients with the Common Cold Do Not Have Lower Respiratory Tract Symptoms
    • However, Some Etiologies of the Common Cold Can (Influenza Virus, Respiratory Syncytial Virus, Parainfluenza Virus) Also Produce Lower Respiratory Tract Findings (Such as Acute Tracheobronchitis, Bronchiolitis, and Pneumonia)
      • For Example, Respiratory Syncytial Virus Can Cause Both Upper Respiratory Tract Disease (Such as the Common Cold) and Lower Respiratory Tract Disease in Children/Older Adults/Immunocompromised Patients (see Respiratory Syncytial Virus)

Prevention

Hand Hygiene

  • Clinical Efficacy
    • Hand Hygiene Decreases the Spread of Respiratory Viruses (Especially Among Children) (Cochrane Database Syst Rev, 2010) [MEDLINE]

Face Mask

  • Clinical Efficacy of Masks for Protection Against Transmission of Viruses
    • All Types of Face Masks Decrease Exposure to Viral Respiratory Pathogens (PLoS One, 2008) [MEDLINE]
      • This was Unaffected by the Duration of Wear or Type of Activity, But There was a High Degree of Individual Variation
    • Cotton Masks, Surgical Masks, and N95 Masks Provide Some Protection Against the Transmission of SARS-CoV-2 Droplets/Aerosols (mSphere. 2020) [MEDLINE]
    • Face Masks Decrease Respiratory Particle Emissions by Up to 90% (Sci Rep, 2020) [MEDLINE]
    • In a Study of an Outbreak of SARS-CoV-2 on the USS Theodore Roosevelt, Wearing Faec Masks Decreased Infections by Up to 70% (MMWR, 2020) [MEDLINE]
    • Face Masks Decrease Cases of Influenza, Respiratory Syncytial Virus, and Other Viral Respiratory Infections (BMJ, 2020) [MEDLINE] (Int J Infect Dis, 2021) [MEDLINE]
    • Face Masks Decrease SARS-CoV-2 Transmission ((JAMA, 2021) [MEDLINE]

Probiotics

  • Clinical Efficacy
    • In a Meta-Analysis, Probiotics (Lactobacillus, Bifidobacterium) were Better than Placebo in Terms of Decreasing the Number of Participants Experiencing Episodes of Acute Upper Respiratory Tract Infection, the Mean Duration of an episode of Acute Upper Respiratory Tract Infection, Antibiotic Use, and Common Cold-Related School Absence (Cochrane Database Syst Rev. 2015) [MEDLINE]
      • Evidence Quality was Low/Very Low

Exercise

  • Clinical Efficacy
    • One Year of Moderate-Intensity Exercise Training Decreased the Incidence of the Common Cold in Postmenopausal Women (Am J Med, 2006) [MEDLINE]
    • Randomized Trial Compared No Intervention with Exercise (45 min Daily at Home Plus 2.5 hrs Per Week of Group Sessions) or Mindfulness Meditation Had No Effect on the Incidence of Acute Respiratory Illness, Severity of Symptoms, or Missed Work Days (Ann Fam Med, 2012) [MEDLINE]
      • However, There was a Trend Toward Meditation Being Associated with Decreased Self-Reported Global Symptom Severity and Fewer Missed Work Days
    • In a Systematic Review/Meta-Analysis, There was an Unclear Effect of Exercise on Prevention of the Common Cold (Cochrane Database Syst Rev, 2015) [MEDLINE]

Sleep

  • Clinical Efficacy
    • In Patients Experimentally Inoculated with Rhinovirus, Patients Who Slept <5 Hours Per Night at Baseline were Almost 3-Fold More Likely to Develop a Common Cold than Patients Who Slept >7 Hours Per Night (Cochrane Database Syst Rev, 2013) [MEDLINE]

Zinc (see Zinc)

  • Clinical Efficacy
    • In Children, Zinc Sulfate (Taken for a Minimum of 5 Months) Decreased the Incidence of the Common Cold and School Absence (Cochrane Database Syst Rev, 2013) [MEDLINE]
    • Importantly, Intranasal Zinc May Cause Anosmia and Any Potential Benefit to its Use May Be Outweighed by This Risk (see Anosmia)

Vitamin C (see Vitamin C)

  • Clinical Efficacy
    • Regular Vitamin C Supplementation Did Not Significantly Decrease the Incidence of the Common Cold (Cochrane Database Syst Rev, 2013) [MEDLINE]

Vitamin D (see Vitamin D)

  • Clinical Efficacy
    • Serum 25(OH)D Levels were Found to Be Inversely Correlated with Recent Upper Respiratory Tract Infections (Arch Intern Med, 2009) [MEDLINE]
    • In a Randomized Trial, Monthly Administration of 100,000 IU of Vitamin D Did Not Decrease the Incidence/Severity of Upper Respiratory Tract Infections in Health Adults (JAMA. 2012) [MEDLINE]
    • In a Randomized Trial, Supplementation with 1000 IU/Day Vitamin D(3) Did Not Significantly Decrease the Incidence/Duration of Upper Respiratory Tract Infections in Adults with a Baseline Serum 25-Hydroxyvitamin D Level ≥12 ng/mL (Clin Infect Dis, 2013) [MEDLINE]

Vitamin E (see Vitamin E)

  • Clinical Efficacy
    • In a Post-Hoc Analysis, Vitamin E (200 IU/Day) Modestly Decreased the Incidence of the Common Cold (0.67 vs 0.81 per Person Pear Year, Relative Risk 0.83 with 95% CI: 0.68-1.01) (JAMA, 2004) [MEDLINE]
    • High-Dose (≥400 IU/Day) Vitamin E Supplementation Increased the All-Cause Mortality Rate (Ann Intern Med, 2005) [MEDLINE]

Herbal Products

Garlic (see Garlic)

  • Clinical Efficacy
    • No Benefit of Garlic in the Prevention of the Common Cold (Cochrane Database Syst Rev, 2014) [MEDLINE]

Ginseng (see Ginseng)

  • Clinical Efficacy
    • No Benefit of Ginseng in Prevention of the Common Cold (Evid Based Complement Alternat Med, 2011) [MEDLINE]

Gargling

  • Simple Water Gargling (3x/Day) was Effective in the Incidence of Cold Symptoms in Healthy Patients (Am J Prev Med, 2005) [MEDLINE]
    • However, This Trial was Unblinded, Raising Questions of Validity of the Findings

Leukotriene Receptor Antagonists

Montelukast (Singulair) (see Montelukast)

  • Clinical Efficacy
    • Montelukast Decreased the Incidence of Common Cold-Like Symptoms in Children with Asthma (Am J Respir Crit Care Med, 2005) [MEDLINE]
    • Montelukast Decreased the Incidence of Common Cold-Like Symptoms in Adults with Asthma (Allergol Int, 2007) [MEDLINE]

Echinacea (see Echinacea)

  • Clinical Efficacy
    • Echinacea is Not Efficacious in the Prevention of Community-Acquired Upper Respiratory Tract Infection (Arch Fam Med, 1998) [MEDLINE] (Am J Med, 1999) [MEDLINE]
    • In a Systematic Review, Echinacea Had a Positive (But Not Significant) Trend (Absolute Risk Reduction of 10%) Toward Decreasing the Incidence of the Common Cold (Cochrane Database Syst Rev. 2014) [MEDLINE]

Treatment

Treatments with Possible Efficacy

Analgesics

  • Acetaminophen (Tylenol) (see Acetaminophen)
    • Clinical Efficacy
      • Aspirin 500 mg and 1000 mg and Acetaminophen 500 mg and 1000 mg were Effective Against Fever and Other Symptoms of Upper Respiratory Tract Infection, as Compared to Placebo (Clin Ther, 2005) [MEDLINE]
  • Ibuprofen (Advil) (see Ibuprofen)
    • Clinical Efficacy
      • NSAID’s are Somewhat Effective in Relieving Discomfort Caused by the Common Cold , But There is No Clear Evicence that They Decrease Respiratory Symptoms (Cochrane Database Syst Rev, 2015) [MEDLINE]
      • Ibuprofen Might Provide Short-Term Control of Symptoms in Patients with Chest infections (BMJ, 2013) [MEDLINE]
  • Aspirin (see Aspirin)
    • Clinical Efficacy
      • Aspirin 500 mg and 1000 mg and Acetaminophen 500 mg and 1000 mg were Effective Against Fever and Other Symptoms of Upper Respiratory Tract Infection, as Compared to Placebo (Clin Ther, 2005) [MEDLINE]
      • NSAID’s are Somewhat Effective in Relieving Discomfort Caused by the Common Cold , But There is No Clear Evicence that They Decrease Respiratory Symptoms (Cochrane Database Syst Rev, 2015) [MEDLINE]

Antihistamine/Decongestant Combinations (see xxxx)

  • Clinical Efficacy
    • Antihistamine/Analgesic/Decongestant Combinations Had Some General Benefit in Adults and Older Children in Treatment of the Common Cold (Cochrane Database Syst Rev, 2012) [MEDLINE]
      • Benefits Must Be Weighed Against the Risk of Adverse Effects (Drowsiness, Dry Mouth, Insomnia, Dizziness)
      • There was No Evidence of Effectiveness Demonstrated in Young Children

Intranasal/Inhaled Cromolyn Sodium (see Cromolyn Sodium)

  • Clinical Efficacy
    • Sodium Cromoglycate Administered Both by Inhalation and Intranasally was an Effective Treatment for the Symptoms of Upper Respiratory Tract Infections (Clin Exp Allergy, 1996) [MEDLINE]

Intranasal ipratropium Bromide (see ipratropium Bromide)

  • Clinical Efficacy
    • Intranasal ipratropium Bromide was Likely Effective in Decreasing Rhinorrhea (Cochrane Database Syst Rev, 2013) [MEDLINE]
      • There was 2-Fold Increased Risk of Adverse Effects (Nasal Dryness, Blood-Tinged Mucous, Epistaxis) with Ipratropium Use

Treatments with Minimal/Uncertain Efficacy

Dextromethorphan

  • Clinical Efficacy
    • Dextromethorphan Likely Has a Small Benefit (12-36% Decrease in Cough Events) When Used in the Treatment of the Common Cold (Clin Exp Allergy, 1996) [MEDLINE] (Cochrane Database Syst Rev, 2013) [MEDLINE]

Decongestants

  • Agents
    • Oxymetazoline (Afrin) (see Oxymetazoline)
    • Phenylephrine (Nasop, Sudafed PE, Sudogest PE, Neo-Synephrine, Ah-Chew D, Despec-SF, Biorphen, Lusonal, Sudafed PE Quick Dissolve, Sudafed PE Extra Strength, Triaminic Thin Strips Nasal Congestion, Triaminic Toddler Congestion Thin Strips, Nasop12, Dimetapp Cold Drops, Triaminic Thin Strips Cold, Triaminic Thin Strips Infant Decongestant, Dimetapp Children’s Cold & Allergy, Phenyl-T, PediaCare Children’s Decongestant, Sudafed PE Children’s Nasal Decongestant, Vazculep, Sudafed PE Congestion) (see Phenylephrine): oral
    • Pseudoephedrine (Chlor Trimeton Nasal Decongestant, Contac Cold, Drixoral Decongestant Non-Drowsy, Elixsure Decongestant, Entex, Genaphed, Kid Kare Drops, Nasofed, Seudotabs, Silfedrine, Sudafed, Sudafed 12-Hour, Sudafed 24-Hour, Sudafed Children’s Nasal Decongestant, Sudodrin, SudoGest, SudoGest 12 Hour, Suphedrin, Triaminic Softchews Allergy Congestion, Unifed) (see Pseudoephedrine): oral
      • The Sale of Pseudoephedrine is Restricted in the US, as it Can Be Used to Manufacture Amphetamines [LINK]
  • Clinical Efficacy
    • A Single Oral Dose of Nasal Decongestant in the Common Cold is Modestly Effective (6% Decrease in Symptoms) for the Short-Term Relief of Nasal Congestion in Adults and These Drugs Also Provide Benefit (4% Decrease in Symptoms) in Some Patients After Regular Use Over 3-5 Days (Cochrane Database Syst Rev, 2007) [MEDLINE]
    • Insufficient Evidence that Oral Phenylephrine is Effective for Nonprescription Use as a Nasal Decongestant (Ann Pharmacother, 2007) [MEDLINE]
    • During a 6 hr Observation Period After Grass Pollen Challenge, a Single Dose of Pseudoephedrine (Oral, 60 mg), But Not Phenylephrine (Oral, 12 mg), Resulted in a Significant Improvement in Nasal Congestion (Ann Allergy Asthma Immunol, 2009) [MEDLINE]
      • Neither Phenylephrine Nor Pseudoephedrine Had an Effect on Non-Nasal Symptoms
    • Antihistamine/Analgesic/Decongestant Combinations Had Some General Benefit in Adults and Older Children in Treatment of the Common Cold (Cochrane Database Syst Rev, 2012) [MEDLINE]
      • Benefits Must Be Weighed Against the Risk of Adverse Effects (Drowsiness, Dry Mouth, Insomnia, Dizziness)
      • There was No Evidence of Effectiveness Demonstrated in Young Children
  • Recommendations/Precautions
    • Topical Decongestant (Afrin, etc) Use Should Be Limited to 2-3 Days, as Rebound Rhinitis Can Occur with Longer Duration of Use (see Oxymetazoline)
    • Topical Decongestant May Occasionally Be Complicated by Epistaxis, Agitation, Insomnia, and Worsened Hypertension in Patients with Preexisting Hypertension

Saline Nasal Spray

  • Clinical Efficacy
    • In a Systematic Review, Nasal Saline Irrigation Possibly Had Clinical Benefit for the Relief of Upper Respiratory Tract Symptoms (Cochrane Database Syst Rev, 2015) [MEDLINE]
      • However, the Included trials were Small and Had a High Risk of Bias

Expectorants

  • Agents
    • Guaifenesin (Mucinex, Robitussin Mucus + Chest Congestion, Triaminic Chest Congestion, Tussin Expectorant, Xpect, Organidin NR, Bidex 400) (see Guaifenesin)
  • Clinical Efficacy
    • In a Randomized Trial, Guaifenesin Had a Marginal Effect,as Compared to Placebo, on Cough (Ann Allergy Asthma Immunol, 1997) [MEDLINE]
    • In a Systematic Review, Evaluation of Overall Efficacy of the Effect of Over-the-Counter Medications (Guaifenesin, Mucolytics, and Combination Medications) for Acute Cough in Children/Adults was Difficult (Cochrane Database Syst Rev, 2014) [MEDLINE]

Herbal Products

  • Clinical Efficacy
    • Elderberry Extract May Be Useful in the Treatment of Influenza A/B Infection (J Int Med Res, 2004) [MEDLINE]
      • Findings Need to Be Confirmed in Larger Studies
    • Pelargonium Sidoides Decreased the Severity of Symptoms and Shortened the Duration of the Common Cold, as Compared to Placebo (Explore-NY, 2007) [MEDLINE]
      • Pelargonium Sidoides (EPs 7630) was a Well-Tolerated and Effective Treatment for Acute Bronchitis in Adults (Outside the Very Restricted Indication for an Antibiotic Therapy) (Curr Med Res Opin, 2007) [MEDLINE]
    • In a Systematic Review, Sambuci Fructus (from European Elder) May Be Useful in the Treatment of Influenza Infection (Phytother Res, 2010)[MEDLINE]
      • Findings Need to Be Confirmed in Larger Studies

Zinc (see Zinc)

  • Contraindications
    • Intranasal Zinc (Zicam) Use (Due to Risk of Permanent Anosmia) (see Anosmia) [US FDA Advisory]
    • Homeopathic Preparation of Intranasal Zinc Gluconate Has Been Associated with Hyposmia/Anosmia (Arch Otolaryngol Head Neck Surg, 2010) [MEDLINE]
  • Clinical Efficacy
    • Zinc Sulfate Syrups/Lozenges are Better Tolerated than Zinc Tablets (Cochrane Database Syst Rev, 2011) [MEDLINE]
    • In a Systematic Review, Oral Zinc Lozenges (at High Daily Dose >75 mg) Decreased the Duration of Common Cold Symptoms (Open Respir Med J, 2011) [MEDLINE]
    • In a Systematic Review/Meta-Analysis, Oral Zinc Decreased the Duration of Common Cold Symptoms (CMAJ, 2012) [MEDLINE]
      • Adverse Effects (Bad Taste, Nausea) were Common
    • Zinc (Dose of ≥75 mg/Day) Taken within 24 hrs of Symptom Onset Decreased the Duration of Common Cold Symptoms (Cochrane Database Syst Rev, 2013) [MEDLINE]

Treatments with No Efficacy

Antibiotics

  • Clinical Efficacy
    • In a Systematic Review in Children/Adults with Upper Respiratory Symptoms for <7 Days, Antibiotics Did Not Impact the Duration of Symptoms (Cochrane Database Syst Rev, 2013) [MEDLINE]
      • However, Adults Who Received Antibiotics Had a Significantly Higher Risk of Adverse Effects (Risk Ratio 2.62; CI: 1.32-5.18)
    • Use of Antibiotics in the Treatment of the Common Cold are Not of Clinical Benefit (Ann Intern Med, 2016) [MEDLINE]
  • Clinical Data-Inappropriate Antibiotic Use
    • In a Low-Risk Elderly Cohort (n = 180,000, Age ≥66 y/o), 46% of Patients with a Nonbacterial Acute Upper Respiratory Infection (Predominantly Common Colds) were Inappropriately Prescribed Antibiotics (Ann Intern Med, 2017) [MEDLINE]
      • Patients were More Likely to Receive Antibiotic Prescriptions from Mid or Late-Career Physicians with High Patient vVolumes and from Physicians Who were Trained Outside of Canada or the United States

Antihistamines (Alone)

  • Agents
  • Clinical Efficacy
    • First-Generation Antihistamines May Decrease Symptoms of Rhinorrhea and Sneezing in the Common Cold, But Their Use is Limited by Adverse Side Effects (Sedation, Dry Eyes, Dry Nose, Dry Mouth) (Ann Allergy Asthma Immunol. 1997) [MEDLINE]
    • In a Systematic Review of Patients with the Common Cold, Antihistamines Had a Limited (on Days 1-2 of Treatment) Beneficial Effect on Overall Symptom Severity, But No Effect in the Mid to Long-Term (Cochrane Database Syst Rev, 2015) [MEDLINE]
      • There was No Clinical Efficacy on Nasal Obstruction, Rhinorrhea, or Sneezing
      • Side Effects were More Common with Sedating Antihistamines
      • There was No Evidence of Clinical Efficacy of Antihistamine Use in Children

Antivirals

  • Clinical Efficacy
    • In a Trial of Combined NSAID’s (Ibuprofen), Antihistamines (Chlorpheniramine), and Antiviral Agent (Intranasal Interferon-α2b, Which is Active Against Rhinovirus) in the Treatment of Experimentally-Induced Common Cold, Patients Receiving the Interferon-α2b Regimen Had a 33-73% Decrease in Symptoms, Decreased Nasal Mucous Volume, and Decreased Virus Concentration in Nasal Mucous (J Infect Dis. 2002) [MEDLINE]
      • This Data is Applicable Only to Rhinovirus-Associated Common Colds

Vitamin C (see Vitamin C)

  • Clinical Efficacy
    • In a Meta-Analysis (29 Trials), Routine/Regular Supplementation with Vitamin C (at Least 200 mg/Day) Resulted in a Modest 8% Decrease in the Duration of Common Cold Symptoms (Cochrane Database Syst Rev, 2013) [MEDLINE]
      • Vitamin C Given Therapeutically After Common Cold Symptom Onset Did Not Decrease Symptom Duration or Severity

Echinacea (see Echinacea)

  • General Comments
    • There is Controversy Regarding the Best Echinacea Species, Part of the Plant, Active Component, and Required Dose
  • Clinical Efficacy
    • In a Systematic Review of Echinacea in the Treatment of the Common Cold, There was No Clinical Benefit (Cochrane Database Syst Rev, 2014) [MEDLINE]

Codeine (see Codeine)

  • Clinical Efficacy
    • Codeine Has No Clinical Benefit in Treatment of the Common Cold (Cochrane Database Syst Rev, 2014) [MEDLINE]

Intranasal Glucocorticoids

  • Clinical Efficacy
    • Intranasal Glucocorticoids Have No Clinical Benefit in Treatment of the Common Cold (Cochrane Database Syst Rev, 2015) [MEDLINE]

Heated, Humidified Air

  • Clinical Efficacy
    • Heated, Humidified Air Has No Clinical Benefit in the Treatment of the Common Cold (BMJ, 2013) [MEDLINE] (Cochrane Database Syst Rev, 2017) [MEDLINE]
      • Incidence of Mild Thermal Injury is Low (Around 2%)

References

General

  • Transmission of the common cold to volunteers under controlled conditions. 1 The common cold as a clinical entity. Arch Intern Med, 1958; 101: 267–78 [MEDLINE]
  • Transmission of the common cold to volunteers under controlled conditions. IV. Specific immunity to the common cold. J Clin Invest. 1959 May;38(5):762-9 [MEDLINE]
  • Computed tomographic study of the common cold. N Engl J Med. 1994 Jan 6;330(1):25-30. doi: 10.1056/NEJM199401063300105 [MEDLINE]
  • The common cold. Prim Care. 1996;23(4):657 [MEDLINE]
  • Epidemiology, pathogenesis, and treatment of the common cold. Ann Allergy Asthma Immunol. 1997;78(6):531 [MEDLINE]
  • The common cold. Lancet. 2003;361(9351):51 [MEDLINE]
  • Effects of acetylsalicylic acid on sore throat pain and other pain symptoms associated with acute upper respiratory tract infection. Pain Med. 2003 Jun;4(2):118-24. doi: 10.1046/j.1526-4637.2003.03019.x [MEDLINE]

Epidemiology/Risk Factors

  • Psychological stress and susceptibility to the common cold. N Engl J Med. 1991 Aug;325(9):606-12 [MEDLINE]
  • Exercise, upper respiratory tract infection, and the immune system. Med Sci Sports Exerc. 1994 Feb;26(2):128-39 [MEDLINE]
  • Studies of the community and family: acute respiratory illness and infection. Epidemiol Rev. 1994;16(2):351-73 [MEDLINE]
  • Epidemiology, pathogenesis, and treatment of the common cold. Ann Allergy Asthma Immunol. 1997;78(6):531 [MEDLINE]
  • The economic burden of non-influenza-related viral respiratory tract infection in the United States. Arch Intern Med. 2003;163(4):487 [MEDLINE]
  • Sleep habits and susceptibility to the common cold. Arch Intern Med. 2009;169(1):62 [MEDLINE]

Etiology

  • Human bocaviruses and paediatric infections. Lancet Child Adolesc Health. 2019 Jun;3(6):418-426. doi: 10.1016/S2352-4642(19)30057-4 [MEDLINE]

Physiology

  • Quantitative rhinovirus shedding patterns in volunteers. Am Rev Respir Dis. 1966;94(2):159 [MEDLINE]
  • Histopathologic examination and enumeration of polymorphonuclear leukocytes in the nasal mucosa during experimental rhinovirus colds. Acta Otolaryngol Suppl 1984; 413: 19–24 [MEDLINE]
  • Epidemiology, pathogenesis, and treatment of the common cold. Ann Allergy Asthma Immunol. 1997;78(6):531 [MEDLINE]
  • Aircraft cabin air recirculation and symptoms of the common cold. JAMA. 2002;288(4):483 [MEDLINE]
  • Effect of antibacterial home cleaning and handwashing products on infectious disease symptoms: a randomized, double-blind trial. Ann Intern Med. 2004;140(5):321 [MEDLINE]
  • Viral titers in nasal lining fluid compared to viral titers in nasal washes during experimental rhinovirus infection. J Clin Virol. 2004;30(4):326 [MEDLINE]
  • Virucidal hand treatments for prevention of rhinovirus infection. J Antimicrob Chemother. 2005;56(5):805 [MEDLINE]
  • Sequencing and analyses of all known human rhinovirus genomes reveal structure and evolution. Science. 2009;324(5923):55 [MEDLINE]
  • Influenza A Virus Infection Triggers Pyroptosis and Apoptosis of Respiratory Epithelial Cells through the Type I Interferon Signaling Pathway in a Mutually Exclusive Manner. J Virol. 2018 Jun 29;92(14):e00396-18 [MEDLINE]

Diagnosis

  • Prevalence of incidental abnormalities on computed tomographic scans of the paranasal sinuses. Arch Otolaryngol Head Neck Surg. 1988;114(8):856 [MEDLINE]
  • Paranasal sinus bony anatomic variations and mucosal abnormalities: CT analysis for endoscopic sinus surgery. Laryngoscope. 1991;101(1 Pt 1):56 [MEDLINE]
  • Procalcitonin-guided antibiotic use vs a standard approach for acute respiratory tract infections in primary care. Arch Intern Med. 2008;168(18):2000 [MEDLINE]
  • Clinical utility of PCR for common viruses in acute respiratory illness. Pediatrics. 2014;133(3):e538 [MEDLINE]
  • Procalcitonin Levels in Acute Respiratory Infection. Viral Immunol. 2016;29(2):128 [MEDLINE]
  • Effects of procalcitonin testing on antibiotic use and clinical outcomes in patients with upper respiratory tract infections. An individual patient data meta-analysis. Clin Chem Lab Med. 2017;56(1):170 [MEDLINE]
  • Syndromic Panel-Based Testing in Clinical Microbiology. Clin Microbiol Rev. 2017 Nov 15;31(1):e00024-17. doi: 10.1128/CMR.00024-17 [MEDLINE]
  • The role of the NxTAG® respiratory pathogen panel assay and other multiplex platforms in clinical practice. Expert Rev Mol Diagn. 2017 Jan;17(1):9-17. doi: 10.1080/14737159.2017.1266260 [MEDLINE]
  • Asymptomatic Shedding of Respiratory Virus among an Ambulatory Population across Seasons. mSphere. 2018;3(4) [MEDLINE]
  • Asymptomatic Summertime Shedding of Respiratory Viruses. J Infect Dis. 2018;217(7):1074 [MEDLINE]
  • Performance of a multiplex PCR pneumonia panel for the identification of respiratory pathogens and the main determinants of resistance from the lower respiratory tract specimens of adult patients in intensive care units. J Microbiol Immunol Infect. 2019 Dec;52(6):920-928. doi: 10.1016/j.jmii.2019.10.009 [MEDLINE]

Clinical

  • Transmission of the common cold to volunteers under controlled conditions. I. The common cold as a clinical entity. AMA Arch Intern Med. 1958;101(2):267 [MEDLINE]
  • Signs and symptoms in common colds. Epidemiol Infect 1993; 111: 143–56 [MEDLINE]
  • Virus-induced airway hyperresponsiveness. Role of inflammatory cells and mediators. Am J Respir Crit Care Med. 1995;151(5):1666 [MEDLINE] The incidence of respiratory tract infection in adults requiring hospitalization for asthma. Chest. 1997;112(3):591 [MEDLINE]
  • Otitis Media. Lancet. 2004;363(9407):465 [MEDLINE]
  • Understanding the symptoms of the common cold and influenza. Lancet Infect Dis. 2005;5(11):718 [MEDLINE]
  • Relations among questionnaire and laboratory measures of rhinovirus infection. Eur Respir J. 2006;28(2):358 [MEDLINE]
  • Pan-viral screening of respiratory tract infections in adults with and without asthma reveals unexpected human coronavirus and human rhinovirus diversity. J Infect Dis. 2007;196(6):817 [MEDLINE]
  • Validation of a short form Wisconsin Upper Respiratory Symptom Survey (WURSS-21). Health Qual Life Outcomes. 2009;7:76 [MEDLINE]
  • How long does a cough last? Comparing patients’ expectations with data from a systematic review of the literature. Ann Fam Med. 2013;11(1):5 [MEDLINE]
  • Comparison of COVID-19 and common cold chemosensory dysfunction. Rhinology. 2020 Dec 1;58(6):623-625. doi: 10.4193/Rhin20.251 [MEDLINE]

Prevention

  • Echinacea root extracts for the prevention of upper respiratory tract infections: a double-blind, placebo-controlled randomized trial. Arch Fam Med. 1998;7(6):541 [MEDLINE]
  • A randomized controlled trial of the effect of fluid extract of Echinacea purpurea on the incidence and severity of colds and respiratory infections. Am J Med. 1999;106(2):13 [MEDLINE]
  • Vitamin E and respiratory tract infections in elderly nursing home residents: a randomized controlled trial. JAMA. 2004;292(7):828 [MEDLINE]
  • Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality. Ann Intern Med. 2005;142(1):37 [MEDLINE]
  • Prevention of upper respiratory tract infections by gargling: a randomized trial. Am J Prev Med. 2005;29(4):302 [MEDLINE]
  • Montelukast reduces asthma exacerbations in 2- to 5-year-old children with intermittent asthma. Am J Respir Crit Care Med. 2005;171(4):315 [MEDLINE]
  • Moderate-intensity exercise reduces the incidence of colds among postmenopausal women. Am J Med. 2006;119(11):937 [MEDLINE]
  • Clinical evaluation of leukotriene receptor antagonists in preventing common cold-like symptoms in bronchial asthma patients. Allergol Int. 2007;56(3):263 [MEDLINE]
  • Association between serum 25-hydroxyvitamin D level and upper respiratory tract infection in the Third National Health and Nutrition Examination Survey. Arch Intern Med. 2009;169(4):384 [MEDLINE]
  • Physical interventions to interrupt or reduce the spread of respiratory viruses. Cochrane Database Syst Rev. 2010 Jan 20;(1):CD006207. doi: 10.1002/14651858.CD006207.pub3 [MEDLINE]
  • North American (Panax quinquefolius) and Asian Ginseng (Panax ginseng) Preparations for Prevention of the Common Cold in Healthy Adults: A Systematic Review. Evid Based Complement Alternat Med. 2011;2011:282151 [MEDLINE]
  • Effect of vitamin D3 supplementation on upper respiratory tract infections in healthy adults: the VIDARIS randomized controlled trial. JAMA. 2012;308(13):1333 [MEDLINE]
  • Meditation or exercise for preventing acute respiratory infection: a randomized controlled trial. Ann Fam Med. 2012 Jul;10(4):337-46 [MEDLINE]
  • Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2013 Jan 31;2013(1):CD000980. doi: 10.1002/14651858.CD000980.pub4 [MEDLINE]
  • Zinc for the common cold. Cochrane Database Syst Rev. 2013 Jun 18;(6):CD001364. doi: 10.1002/14651858.CD001364.pub4 [MEDLINE]
  • Vitamin D3 supplementation and upper respiratory tract infections in a randomized, controlled trial. Clin Infect Dis. 2013;57(10):1384 [MEDLINE]
  • Garlic for the common cold. Cochrane Database Syst Rev. 2014 Nov 11;2014(11):CD006206. doi: 10.1002/14651858.CD006206.pub4. [MEDLINE]
  • Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev. 2014 Feb 20;2(2):CD000530. doi: 10.1002/14651858.CD000530.pub3. [MEDLINE]
  • Exercise versus no exercise for the occurrence, severity and duration of acute respiratory infections. Cochrane Database Syst Rev. 2015 Jun 16;(6):CD010596. doi: 10.1002/14651858.CD010596.pub2 [MEDLINE]
  • Probiotics for preventing acute upper respiratory tract infections. Cochrane Database Syst Rev. 2015 Feb 3;(2):CD006895. doi: 10.1002/14651858.CD006895.pub3 [MEDLINE]

Treatment

  • Effects of antibiotic treatment in the subset of common-cold patients who have bacteria in nasopharyngeal secretions. Lancet. 1996;347(9014):1507 [MEDLINE]
  • The effect of inhaled and intranasal sodium cromoglycate on symptoms of upper respiratory tract infections. Clin Exp Allergy. 1996;26(9):1045 [MEDLINE]
  • Colour of respiratory discharge and antibiotic use. Lancet. 1997;350(9084):1077 [MEDLINE]
  • Epidemiology, pathogenesis, and treatment of the common cold. Ann Allergy Asthma Immunol. 1997;78(6):531 [MEDLINE]
  • Combined antiviral-antimediator treatment for the common cold. J Infect Dis. 2002;186(2):147 [MEDLINE]
  • Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infections. J Int Med Res. 2004;32(2):132 [MEDLINE]
  • Aspirin compared with acetaminophen in the treatment of fever and other symptoms of upper respiratory tract infection in adults: a multicenter, randomized, double-blind, double-dummy, placebo-controlled, parallel-group, single-dose, 6-hour dose-ranging study. Clin Ther. 2005 Jul;27(7):993-1003 [MEDLINE]
  • Topical glucocorticosteroids in rhinitis: clinical aspects. Acta Otolaryngol. 2006;126(10):1022 [MEDLINE]
  • Nasal decongestants for the common cold. Cochrane Database Syst Rev. 2007 Jan 24;(1):CD001953. doi: 10.1002/14651858.CD001953.pub3 [MEDLINE]
  • Efficacy and safety of oral phenylephrine: systematic review and meta-analysis. Ann Pharmacother. 2007;41(3):381 [MEDLINE]
  • Efficacy of a pelargonium sidoides preparation in patients with the common cold: a randomized, double blind, placebo-controlled clinical trial. Explore (NY). 2007;3(6):573 [MEDLINE]
  • Treatment of acute bronchitis with a liquid herbal drug preparation from Pelargonium sidoides (EPs 7630): a randomised, double-blind, placebo-controlled, multicentre study. Curr Med Res Opin. 2007;23(2):323 [MEDLINE]
  • Antibiotic prescribing for self limiting respiratory tract infections in primary care: summary of NICE guidance. BMJ. 2008;337:a437 [MEDLINE]
  • A placebo-controlled study of the nasal decongestant effect of phenylephrine and pseudoephedrine in the Vienna Challenge Chamber. Ann Allergy Asthma Immunol. 2009;102(2):116 [MEDLINE]
  • The Bradford Hill criteria and zinc-induced anosmia: a causality analysis. Arch Otolaryngol Head Neck Surg. 2010;136(7):673 [MEDLINE]
  • A systematic review on the sambuci fructus effect and efficacy profiles. Phytother Res. 2010;24(1):1 [MEDLINE]
  • Zinc for the common cold. Cochrane Database Syst Rev. 2011 Feb 16;(2):CD001364. doi: 10.1002/14651858.CD001364.pub3 [MEDLINE]
  • Zinc lozenges may shorten the duration of colds: a systematic review. Open Respir Med J. 2011;5:51-8 [MEDLINE]
  • Zinc for the treatment of the common cold: a systematic review and meta-analysis of randomized controlled trials. CMAJ. 2012;184(10):E551 [MEDLINE]
  • Oral antihistamine-decongestant-analgesic combinations for the common cold. Cochrane Database Syst Rev. 2012 Feb 15;(2):CD004976. doi: 10.1002/14651858.CD004976.pub3 [MEDLINE]
  • Antibiotics for the common cold and acute purulent rhinitis. Cochrane Database Syst Rev. 2013 Jun 4;2013(6):CD000247. doi: 10.1002/14651858.CD000247.pub3 [MEDLINE]
  • Intranasal ipratropium bromide for the common cold. Cochrane Database Syst Rev. 2013 Jun 19;2013(6):CD008231. doi: 10.1002/14651858.CD008231.pub3. [MEDLINE]
  • Ibuprofen, paracetamol, and steam for patients with respiratory tract infections in primary care: pragmatic randomised factorial trial. BMJ. 2013;347:f6041 [MEDLINE]
  • Over-the-counter (OTC) medications for acute cough in children and adults in community settings. Cochrane Database Syst Rev. 2014 Nov 24;2014(11):CD001831. doi: 10.1002/14651858.CD001831.pub5 [MEDLINE]
  • Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev. 2014 Feb 20;2(2):CD000530. doi: 10.1002/14651858.CD000530.pub3. [MEDLINE]
  • Antihistamines for the common cold. Cochrane Database Syst Rev. 2015 Nov 29;(11):CD009345. doi: 10.1002/14651858.CD009345.pub2 [MEDLINE]
  • Saline nasal irrigation for acute upper respiratory tract infections. Cochrane Database Syst Rev. 2015 Apr 20;(4):CD006821. doi: 10.1002/14651858.CD006821.pub3 [MEDLINE]
  • Corticosteroids for the common cold. Cochrane Database Syst Rev. 2015 Oct 13;(10):CD008116. doi: 10.1002/14651858.CD008116.pub3. [MEDLINE]
  • Appropriate Antibiotic Use for Acute Respiratory Tract Infection in Adults: Advice for High-Value Care From the American College of Physicians and the Centers for Disease Control and Prevention. Ann Intern Med. 2016;164(6):425 [MEDLINE]
  • Antibiotic Prescribing for Nonbacterial Acute Upper Respiratory Infections in Elderly Persons. Ann Intern Med. 2017;166(11):765 [MEDLINE]
  • Heated, humidified air for the common cold. Cochrane Database Syst Rev. 2017 Aug 29;8(8):CD001728. doi: 10.1002/14651858.CD001728.pub6 [MEDLINE]