Development of hyperreactive malarious splenomegaly in an 8 year-old Caucasian boy, 18 months after residence in Africa.

Hyperreactive malarial splenomegaly (the former tropical splenomegaly syndrome) refers to a combination of splenomegaly, high antimalarial antibodies and high serum IgM content, a condition resulting from an aberrant immunological response to malaria. It has rarely been described in expatriates. We report the case of an 8 year-old Dutch boy who developed this syndrome 18 months after returning from Zaire. Treatment with mefloquine resulted in gradual improvement of all laboratory abnormalities. The spleen did not decrease in size, but became normal for age as height increased.