Epidemiology
- Most common complication of varicella in adults (occurs in 0.8-50% of cases): has highest mortality rate of any complication of varicella
- Risk Factors for varicella pneumonia (in presence of varicella):
- Immunosuppression:
- AIDS:
- Pregnancy:
- Tobacco (15x increased risk in smokers):
- Transmission: airborne droplets via person-to-person
Etiology
- Varicella-Zoster Virus (VZV) infection
Physiology
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Pathology
- Diffuse nodular (1-10 mm nodules) infiltrates
Diagnosis
Sputum GS/Cult+Sens:
ABG: hypoxemia
CXR/ Chest CT patterns:
1) Alveolar infiltrates (most common pattern):
-Nodular/ miliary densities may occur (miliary areas may remain as areas of “buckshot” calcification after resolution)
-Hilar adenopathy/small pleural effusions are sometimes seen
-Radiologic findings correlate with and follow the severity of skin rash
2) Nodular Interstitial infiltrates (less common pattern):
3) Miliary calcific pattern (on CXR): resembles old Histo
Clinical
Pulmonary Manifestations
- Pneumonia (see [[Pneumonia]])
- Dyspnea
- Cough
- Rales: correlate poorly with severity of illness
- Interstitial Infiltrates (see [[Interstitial Lung Disease-Etiology]])
- Miliary Nodular Pneumonia (see [[Lung Nodule or Mass]])
- [[Diffuse Alveolar Damage]] -> [[Acute Lung Injury-ARDS]] or [[Diffuse Alveolar Hemorrhage]]
Dermatologic Manifestations
- Vesicular Skin Lesions (see Vesicular-Bullous Skin Lesions, [[Vesicular-Bullous Skin Lesions]])
- Erythema Multiforme (see Erythema Multiforme, [[Erythema Multiforme]])
- Morbilliform Rash (see Exanthems, [[Exanthems]]): may occur early in the course prior to the development of vesicles
Other Manifestations
- SIADH/ ARDS/ encephalitis/ Guillian-Barre syndrome/ GLN/ arthritis/ hepa-titis/ pancreatitis/ myocarditis/ DVT
Shingles
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Treatment
PO Acyclovir (800 mg/day PO x 5 days): effective, if given within 24 hours of onset of rash, to decrease fever/ tachypnea/ hypoxemia/duration of illness
-Effect on complications is unknown
-Risk/benefit ratio favors use in pregnant patients
IV Acyclovir (10 mg/kg IV q8 hrs x 7 days): for VZV pneumonia or VZV in an immunocompromised host
IV Foscarnet (40 mg/kg IV q8 hrs x 10 days): indicated for Acyclovir-resistant VZV
Post-Exposure Prophylaxis (indicated for Varicella-seronegative hosts with close and prolonged exposure): VZV immune globulin
Infection control: airborne precautions
Treatment
- Resolves over days-weeks
References
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