In 1964 Sweet described a new syndrome, characterized by the association of fever, neutrophilic leukocytosis, erythematous plaque affecting the extremities, neck and face, with histologically verified polymorphonuclear perivascular dermal infiltrates and a rapid response to corticosteroids. Although some 100 cases have since then been described the pathogenesis remains obscure. We present two cases which showed all criteria for Sweet's syndrome, in which the initial presentation of acute onset with fever, multiple skin lesions and especially the poor general state on one, made use at first think of an infectious process such as staphylococcal or gonococcal sepsis, in which case diagnosis must be differential. Only when the causal agent is known and an early skin biopsy is done can correct diagnosis and treatment be established.