Varicella pneumonia is an infrequent but severe complication of varicella infection and occurs most commonly in adults. Risk factors for varicella pneumonia include pregnancy, smoking and immunocompromised status. Standard therapy for this condition has been intravenous acyclovir, although even with treatment the mortality rate may be as high as 50 percent. Mer and Richards report data from a combined retrospective and prospective study of 15 patients admitted to the intensive care unit with varicella pneumonia.
The primary end points included length of intensive care and hospital stays, and rate of mortality. The diagnosis of varicella pneumonia was made clinically and was confirmed serologically by detection of IgM varicella antibody. Other data collected included patient demographics, clinical and laboratory features, need for mechanical ventilation, administration of intravenous acyclovir and corticosteroids, associated complications and death rates.
The study consisted of nine men and six women with a median age of 30 years (range: 23 to 63 years). Seven of the patients had documented contact with a child who had chickenpox, and one patient was infected by a spouse who had herpes zoster. All patients had bilateral pulmonary infiltrates documented on chest radiographs. Other noted complications included renal failure, myocarditis, pancreatitis and disseminated intravascular coagulation. All patients had markedly reduced partial pressure of arterial oxygen-percentage of inspired oxygen ratios.
Thirteen of the patients received intravenous acyclovir for at least seven days, and five patients also received 200 mg of hydrocortisone every six hours for 48 hours. The steroids were administered within 24 hours of admission to the intensive care unit.
The median hospital stay for all patients was 12 days. However, the steroid group had a median stay of only 10 days compared with 20 days in the group that did not receive steroids. In addition, the patients who did not receive steroids had a median intensive care stay of 12 days, compared with 5.5 days in the steroid group. No patients in the steroid group died, compared with four of the patients who did not receive steroids, although this difference was not statistically significant.
The authors conclude that the addition of corticosteroids to standard therapy with intravenous acyclovir appears to improve the outcome of patients with life-threatening varicella pneumonia. This response is similar to that seen with the use of steroids in patients with severe Pneumocystis carinii pneumonia. Steroids are beneficial because pneumonitis is a result of the host inflammatory response and not of virally mediated tissue injury. It is also hypothesized that steroids may improve pulmonary hemodynamics. With the administration of varicella vaccine, primary varicella may become a disease occurring most commonly in nonimmunized adults. Since this is the first published data on the use of steroids in the management of varicella pneumonia, the authors believe that their study should form the basis of a randomized controlled trial.