With the occurrence of unclear consciousness conditions primarily internal or neurological causes are considered. Of a systemic mastocytosis one thinks only rarely, which can accompany without or with slight clinically visible skin changes. In the following we report on a patient who has repeated unclear shock conditions and required resuscitation several times without a recognizable cause, with whom a systemic mastocytosis could be proven. Clinically very discrete lesions of mastocytosis were recognizable from the skin. Only an increased tryptase level referred to being present an occult systemic mastocytosis. The diagnostics, potential triggers and therapy of this disease are to be discussed on the basis the available case.