Epidemiology
History
- Acute Eosinophilic Pneumonia was First Associated with Respiratory Illness in 1989 (NEJM, 1989) [MEDLINE]
Comparison with Chronic Eosinophilic Pneumonia (see Chronic Eosinophilic Pneumonia, [[Chronic Eosinophilic Pneumonia]])
- Acute Eosinophilic Pneumonia Typically Has a More Acute Clinical Presentation (<7 Days of Symptoms) than Chronic Eosinophilic Pneumonia
Demographics
- Age Distribution
- Most Cases Occurs Between Age 20-40: although it can occur at any age
- Sex Distribution
- Male:Female Ratio = 2:1
Lack of Relationship to Allergic Disease
- Clinical Data
- Retrospective Series Found that Only 12% of Patients Had a History of Allergic Disease (Eur Respir J, 2013) [MEDLINE]
Risk Factors
- Cocaine (Inhalation) (see Cocaine, [[Cocaine]])
- Epidemiology: case reports
- Dust Exposure
- Heroin (Inhalation) (see Heroin, [[Heroin]])
- Epidemiology: case reports
- Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus, [[Human Immunodeficiency Virus]])
- Epidemiology: case reports
- Tobacco and Other Smoke Exposure
- Epidemiology
- Case Report of Acute Eosinophilic Pneumonia Occurring After Firework Smoke Exposure (Intern Med, 2000) [MEDLINE]
- Case Series Defining a Relationship Between Tobacco Use and Acute Eosinophilic Pneumonia (Chest, 2008) [MEDLINE]
- Recent Alterations in Smoking Habits (Beginning to Smoke, Restarting to Smoke, and Increasing Daily Smoking Doses) were Associated with the Development of Acute Eosinophilic Pneumonia
- Case Report of Acute Eosinophilic Pneumonia Occurring After Passive Smoke Exposure (Allergol Int, 2010) [MEDLINE]
- Urinary Cotinine Levels were Found to Be Elevated in the Patient
- Case Report of Acute Eosinophilic Pneumonia Occurring After Passive Smoke Exposure (Tuberc Respir Dis; Seoul, 2014) [MEDLINE]
- Secondhand Smoke Exposure by the Patient Occurred in an Enclosed Area Over a Period of 4 Weeks
- Large Case Series of Acute Eosinophilic Pneumonia Patients (Eur Respir J, 2013) [MEDLINE]: n = 137
- Approximately 99% of Cases Reported were Current Smokers: approximately half started smoking within 1 mo of developing acute eosinophilic pneumonia
- Epidemiology
Physiology
- Unclear Mechanism: possible hypersensitivity phenomenon
Diagnosis
Complete Blood Count (CBC) (see Complete Blood Count, [[Complete Blood Count]])
- Peripheral Eosinophilia (see Peripheral Eosinophilia, [[Peripheral Eosinophilia]])
- Peripheral Eosinophilia (Defined as Eosinophils >500/μL) was Found in 32% of Cases (Eur Respir J, 2013) [MEDLINE]
- Leukocytosis (see Leukocytosis, [[Leukocytosis]])
- Leukocytosis (WBC >10k/μL) was Found in 71% of Cases (Eur Respir J, 2013) [MEDLINE]
Erythrocyte Sedimentation Rate (ESR) (see Erythrocyte Sedimentation Rate, [[Erythrocyte Sedimentation Rate]])
- Elevated: often >100
Serum C-Reactive Protein (see Serum C-Reactive Protein, [[Serum C-Reactive Protein]])
- Elevated
- Mean CRP was 16.6 (Eur Respir J, 2013) [MEDLINE]
Sputum Culture (see Sputum Culture, [[Sputum Culture]])
- Eosinophilia
Pulse Oximetry/Arterial Blood Gas (ABG) (see Pulse Oximetry, [[Pulse Oximetry]] and Arterial Blood Gas, [[Arterial Blood Gas]])
- Hypoxemia (see Hypoxemia, [[Hypoxemia]])
Pulmonary Function Tests (PFT’s) (see Pulmonary Function Tests, [[Pulmonary Function Tests]])
- Restrictive Defect
- Decreased DLCO
Bronchoscopy (see Bronchoscopy, [[Bronchoscopy]])
Bronchoalveolar Lavage (BAL)
- Eosinophilia >40% (normal <2%) is highly suggestive of eosinophilic pneumonia (BAL eosinophilia is nearly always seen, even when peripheral eosinophilia is absent)
- Mean BAL Eosinophilia was 40% (Range: 35-53%) (Eur Respir J, 2013) [MEDLINE]
- BAL Eosinophilia Resolves with Resolution of the Disease
- Other Cell Percentages
- BAL Neutrophils: 1-16%
- BAL Lymphocytes: 10-30%
Transbronchial Biopsy (TBB)
- May Be Diagnostic
Chest X-Ray (CXR) (see Chest X-Ray, [[Chest X-Ray]])
- Findings
- Reticular and/or Ground-Glass Infiltrates: diffuse distribution (in contrast to the characteristic peripheral distribution seen in chronic eosinophilic pneumonia)
- Kerley B Lines: often present
- Small Pleural Effusions: detected in 70% of cases
- Frequently Bilateral
High-Resolution Chest CT (HRCT) (see High-Resolution Chest Computed Tomography, [[High-Resolution Chest Computed Tomography]])
- Findings
- Patchy Bilateral, Random Ground-Glass or Reticular Infiltrates
- Centrilobular Nodules: occur in 50% of cases
- Alveolar Consolidation: occurs in 40% of cases
- Pleural Effusions: seen in 90% of cases
Serum Immunoglobulin E (IgE) (see Serum Immunoglobulin E, [[Serum Immunoglobulin E]])
- Normal-Mildly Elevated
Circulating Immune Complexes
- Positive
Video-Assisted Thoracoscopic Surgery (VATS) with Lung Biopsy (see Video-Assisted Thoracoscopic Surgery, [[Video-Assisted Thoracoscopic Surgery]])
- Not Usually Required for Diagnosis
- Findings
- Acute and Organizing Diffuse Alveolar Damage: common
- Hyaline Membranes and Interstitial Widening (Due to Edema, Fibroblast Proliferation, and Inflammatory Cell Infiltration): 78% of cases
- Interstitial Eosinophils: prominent
- Alveolar Eosinophils: lesser numbers
- *Type II Pneumocyte Hyperplasia: 55% of cases
- Interstitial Lymphocytes: 100% of cases
- Organizing Intra-Alveolar Fibrinous Exudate: 100% of cases
- Perivascular and Intramural Inflammation without Necrosis: 33% of cases
- Absence of Alveolar Hemorrhage
- Absence of Granulomas
Clinical Manifestations
General Comments
- Course: symptoms are usually present for <1 mo (and often for <1 wk)
Cardiovascular Manifestations
Chest Pain (see Chest Pain, [[Chest Pain]])
- Epidemiology: present in 16% of cases (Eur Respir J, 2013) [MEDLINE]
- Clinical
- Pleuritic: usually
Hematalogic Manifestations
- Lymphadenopathy (see Lymphadenopathy, [[Lymphadenopathy]])
Gastrointestinal Manifestations
- Hepatomegaly (see Hepatomegaly, [[Hepatomegaly]])
- Weight Loss (see Weight Loss, [[Weight Loss]])
Neurologic Manifestations
Headache (see Headache, [[Headache]])
- Epidemiology: present in 29% of cases (Eur Respir J, 2013) [MEDLINE]
Pulmonary Manifestations
Acute Respiratory Failure (see Respiratory Failure, [[Respiratory Failure]])
- Epidemiology
- Approximately 58% of Cases Present with Acute Respiratory Failure (Eur Respir J, 2013) [MEDLINE]
Pneumonia-Like Presentation
- Epidemiology
- Clinical
- Cough (see Cough, [[Cough]]): present in 95% of cases (Eur Respir J, 2013) [MEDLINE]
- Dry or Mucoid Sputum
- Dyspnea (see Dyspnea, [[Dyspnea]]): present in 93% of cases (Eur Respir J, 2013) [MEDLINE]
- Hemoptysis< (see Hemoptysis, [[Hemoptysis]]): occasional
- Inspiratory Crackles: present in 67% of cases (Eur Respir J, 2013)* [MEDLINE]
- Wheezing (see Obstructive Lung Disease, [[Obstructive Lung Disease]]): reported in some cases (generally recent onset)
- Absence of Clubbing
- Absence of Cor Pulmonale
- Cough (see Cough, [[Cough]]): present in 95% of cases (Eur Respir J, 2013) [MEDLINE]
Pleural Effusion (see Pleural Effusion-Exudate, [[Pleural Effusion-Exudate]])
- Epidemiology: present in 90% of cases (by HRCT)
- Diagnosis
- Chest X-Ray (CXR): frequently bilateral
- Pleural Fluid (see Thoracentesis, [[Thoracentesis]])
- Pleural Fluid Eosinophilia: generally 10-50%
- High pH
Other Manifestations
- Chills (see Chills, [[Chills]]): present in 56% of cases (Eur Respir J, 2013) [MEDLINE]
- Fever (see Fever, [[Fever]]): present in 88% of cases (Eur Respir J, 2013) [MEDLINE]
- Myalgias (see Myalgias, [[Myalgias]]): present in 23% of cases (Eur Respir J, 2013) [MEDLINE]
- Night Sweats (see Night Sweats, [[Night Sweats]])
Treatment
Smoking Cessation (see Tobacco, [[Tobacco]])
- May Result in Resolution without Corticosteroids in Milder Cases
Corticosteroids (see Corticosteroids, [[Corticosteroids]])
- Agents
- Prednisone (see Prednisone, [[Prednisone]]): generally indicated for less severe cases
- Administration: 40-60 mg qday
- Methylprednisolone (Solumedrol) (see Methylprednisolone, [[Methylprednisolone]]): generally indicated for more severe cases
- Administration: 60 mg q6hrs
- Prednisone (see Prednisone, [[Prednisone]]): generally indicated for less severe cases
- Rate of Resolution: corticosteroids usually result in rapid resolution within 24-48 hrs
- Pleural Effusions Typically Resolve Slower than the Pulmonary Infiltrates (Medicine; Baltimore, 1996) [MEDLINE]
- Taper of Corticosteroids: over 10 days-12 wks (differs from chronic eosinophilic pneumonia in that it does not recur after corticosteroid withdrawal)
Prognosis
Relapse
- Relapse is Uncommon: when it occurs, it is usually associated with resumption of tobacco abuse (Eur Respir J, 2013)* [MEDLINE]
References
- Acute eosinophilic pneumonia as a reversible cause of noninfectious respiratory failure. N Engl J Med. 1989;321(9):569 [MEDLINE]
- Acute eosinophilic pneumonia: a hypersensitivity phenomenon? Am Rev Respir Dis. 1989 Jan;139(1):249-52 [MEDLINE]
- Acute eosinophilic pneumonia. A summary of 15 cases and review of the literature. Medicine (Baltimore). 1996;75(6):334 [MEDLINE]
- Acute eosinophilic pneumonia associated with smoke from fireworks. Intern Med. 2000;39(5):401 [MEDLINE]
- Acute eosinophilic pneumonia in a New York City firefighter exposed to World Trade Center dust. Am J Respir Crit Care Med. 2002;166(6):797 [MEDLINE]
- Acute eosinophilic pneumonia among US Military personnel deployed in or near Iraq. JAMA. 2004;292(24):2997 [MEDLINE]
- Acute eosinophilic pneumonia. Semin Respir Crit Care Med. 2006 Apr;27(2):142-7 [MEDLINE]
- Alterations in smoking habits are associated with acute eosinophilic pneumonia Chest. 2008 May;133(5):1174-80. doi: 10.1378/chest.07-2669. Epub 2008 Feb 8 [MEDLINE]
- A case of acute eosinophilic pneumonia following short-term passive smoking: an evidence of very high level of urinary cotinine. Allergol Int. 2010 Dec;59(4):421-3. doi: 10.2332/allergolint.10-CR-0203. Epub 2010 Oct 25 [MEDLINE]
- Clinical characteristics and corticosteroid treatment of acute eosinophilic pneumonia. Eur Respir J. 2013;41(2):402 [MEDLINE]
- Acute eosinophilic pneumonia following secondhand cigarette smoke exposure. Tuberc Respir Dis (Seoul). 2014 Apr;76(4):188-91. doi: 10.4046/trd.2014.76.4.188. Epub 2014 Apr 25 [MEDLINE]