Introduction & Objective: There is a need to study the outcomes of admitted patients with primary varicella infections especially for immunocompromised cases like patients with various cancers in our country in which there is no routine vaccination against such a virus. Materials & Methods: We performed a retrospective descriptive-analytic study on the admitted cases with primary varicella infections in Aliasghar children hospital, Tehran, since 1996 to 2009The patients were put in two different groups for comparison: 1)Immunosuppressed patients including patients with acute lymphoblastic leukemia ,patients with other types of cancers ,and patients who were receiving high doses of corticosteroids 2)previously healthy patients. Demographic as well as some indicators of poor general condition on admission like respiratory distress ,hypotension and decreased level of consciousness were compared within the groups we also looked for ataxia as an important indication of admission and the time period since the onset of disease up to admission in each group appropriate statistical methods were used for statistical analysis.

Results: 88 cases including 24 cases of ALL (27%),9 cases with various types of cancers (10.5%),and 13 cases who were receiving high dose of corticosteroid were included. Mean age of the patients was 6 years (SD=3.5.47 cases(53.4%) ) were male. Hypotension on admission was significantly more common in patients under four years of age (P=0.006) The patients in the first 3 groups were admitted significantly earlier(P=0.027) Hypotension and ataxia were more significantly seen in the previously healthy group(P=0.01 and 0.04 respectively). Just one case of mortality occurred in a case of ALL during the study period.

Conclusion: We concluded that immunocompromised cases comprise more than half of the admissions due to primary varicella infections in our referral center interestingly ,however, in comparison with previously healthy cases they have been admitted earlier with better general condition on admission. In contrast, previously healthy group specially in cases under four years of age wereadmitted with significantly poorer general condition and with more delay the second result might be due to inclusion of late onset complication of cerebellitis but the former results shows that better educational programs are needed for both parents and practitioners to pay attention to younger age groups with primary varicella infections.