[One thing begets another]. / Van het een komt het ander.

In this article the signs and symptoms as well as the course and complications are described of a feverish disease contracted by a fourteen year old boy after spending summer-holidays in the southern part of France. In retrospect this disease could be diagnosed as 'Mediterranean spotted fever' In the same period of these manifestations also a partial loss of sight at one eye occurred; although serology tests of antibody titers were negative, it was attributed to chorioretinitis due to activation of a congenital toxoplasmosis. The course was further complicated by an acute renal insufficiency during treatment of the chorioretinitis with high doses sulfadiazine. A short contemplation on the various clinical syndromes is presented.