Relapses after withdrawal of proguanil treatment in tropical splenomegaly syndrome.

After the remission of symptoms and reduction in spleen size while on proguanil therapy four patients with the tropical splenomegaly syndrome defaulted from treatment. The withdrawal of proguanil caused a recrudescence of original symptoms, splenomegaly, and a return of the initially raised serum IgM. Complete return to normal values was again effected with proguanil therapy.The role of the spleen in the tropical splenomegaly syndrome in the production of the raised serum IgM is discussed. These patients should be educated as to the nature of their disease and the importance of continued medical treatment.