Spread of VZV to the lungs is thought to occur hematogenously.
Varicella pneumonia is estimated to occur in fewer than 1% of cases of chickenpox. Varicella pneumonia is seen in children, but it is much more common in adults. Immunocompromised patients, including transplant recipients and pregnant females, are at increased risk. Of note, studies of healthy adults with VZV infection have shown that abnormal chest x-rays are not uncommon, and many patients may not have respiratory symptoms (clinically asymptomatic pneumonitis is possible, but an abnormal chest x-ray should not be disregarded in an immunocompromised patient).
Patients typically develop the rash characteristic of chickenpox or shingles. Within one week, they present with respiratory symptoms. Symptoms may include cough, shortness of breath, tachypnea, or hemoptysis. Occasionally, respiratory symptoms may precede development of the rash (and very rarely, patients may not have any rash).
Chest radiograph changes that can be seen include interstitial changes and nodular infiltrates.
In immunocompromised patients who present with shingles, skin lesions in multiple dermatomes should alert the physician to the possibility of disseminated infection (including possibly pneumonia). One report of renal transplant recipients noted that gastrointestinal and neurologic symptoms may be present on admission. Rash was absent in 2 patients. Other visceral involvement included hepatitis, pancreatitis, and neurological involvement. Many patients developed disseminated intravascular coagulation. Mortality was high.
The time it takes to recover from varicella pneumonia varies. Immunocompromised patients may be hospitalized for many days or weeks.
B01.2 – Varicella pneumonia
195911009 – Chickenpox pneumonia
- Herpes simplex virus – Skin lesions can be difficult to distinguish from lesions due to VZV in some cases. This virus can also cause disseminated visceral infection in immunocompromised patients.
- Group A coxsackieviruses can also cause vesicular lesions. Lesions on the palms and soles can be seen.
- Bacterial infections including impetigo can occasionally present with skin lesions that mimic VZV.
- Immunocompromised patients may have more than one process simultaneously, and similarly chest x-ray findings can be seen with multiple pathogens including respiratory viruses, bacteria, fungi, Nocardia, and mycobacteria. Consultation with experts in infectious diseases is recommended.