Chicken pox associated thrombocytopenia in adults.

Objective: To determine the frequency and magnitude of thrombocytopenia associated with chicken pox in adults.

Design: Observational descriptive study.

Place And Duration Of Study: Combined Military Hospital, Attock, from July 2003 to June 2004.

Patients And Methods: All patients of age 15 years and above with history of fever, followed by appearance of the typical vesicular chicken pox rash, were inducted after informed consent. Two milliliters of whole blood was collected on day 1 of admission, and blood counts were performed. Patients were admitted and given 800 mg oral acyclovir, 5 times/day, for 7 days, in addition to symptomatic treatment. Patients were followed till 8 weeks.

Results: A total of 410 patients of chicken pox were received, out of which 270 were included. Age of patients ranged between 15 and 40 years with median age of 21 years. Platelet count on the day of admission ranged between 29 x 10(9)/L to 513 x 10(9)/L, mean platelet count 178 x 10(9)/L. Platelet count < 150 x 10(9)/L was detected in 80/270 (30%) patients. Platelet count in thrombocytopenia patients was from 29 x 10(9)/L to 149 x 10(9)/L with mean 121 x 10(9)/L. Thrombocytopenia recovered within 02 weeks in 78/80 (97%) patients. In 2 patients, thrombocytopenia recovered in 3 weeks. None of the patients developed purpuric spots, ecchymosis or bleeding manifestations.

Conclusion: Thrombocytopenia in chicken pox is a common entity. Platelet count remains above 25 x 10(9) /L, which is usually not associated with bleeding manifestations. None of the patients in this series developed purpura. No specific pattern of total leukocyte counts was predictive of the progression or regression in platelet count.