Background and aims The purpose of this study was to retrospectively evaluate the severe chickenpox complications among immunocompetent children.

Methods During a 5-year period medical records of children aged.

Results We reviewed 269 cases with varicella admitted to Plovdiv University Hospital, Infectious Diseases Clinic from January 2009 to December 2013. One hundred ninety four were excluded as the reason for admission was dehydration. Another 53 patients, hospitalised due to epidemiological considerations were also excluded. Finally, 22 cases met the definition of severe complications – 12 girls, 10 boys (mean age 4,12). The most common complications were respiratory tract infections (17 cases), followed by thrombocytopenic purpura in 2 and cerebellar ataxia, sepsis and scarlet fever a single case of each one. Patients were admitted 4,8 days post the onset of varicella. The mean duration of hospitalisation was 5,7 days. Antibiotics were administrated in all patients, in 11 acyclovir was also added. All recovered completely without any sequels.

Conclusion Severe complications were rare with respiratory tract infections being the most frequent. Haematological complications, although potentially life-threatening, were uncommon.

Our results indicate that further studies are needed for assessing the burden of varicella, and estimating cost effectiveness of varicella vaccine.