Smouldering systemic mastocytosis presenting with cryptic life-threatening crises: case report and literature review.

Systemic mastocytosis (SM) is a rare, clonal disorder of the mast cell (MC) and its precursor cells. It is characterized by proliferation and accumulation of MCs within various organs, most commonly the skin. The clinical course is variable with indolent or smouldering and aggressive forms being described. We report the case of a middle-aged male patient with smouldering SM presenting with atypical recurrent life-threatening crises. The patient reported a 19-year history of chronic symptoms. The patient had four inpatient stays due to atypical life-threatening crises, during which he has shown end organ damage (cardiac and renal). With each crisis the patient reported acute symptoms. The management of each of these episodes was complex and made more challenging by the patient's longstanding history of hypertension and ischaemic heart disease. In short, SM can present with unexplained life-threatening crises which can be confused for an infectious disease being acute in nature.