Is It Exertional Heatstroke or Something More? A Case Report.

BACKGROUND: Heat stroke, heat-related illness, and malignant hyperthermia all present with hyperthermia. The former two are common presentations in the emergency department (ED). On the other hand, malignant hyperthermia (MH) is an uncommon but equally dangerous condition that requires prompt recognition and specific treatment with dantrolene sodium and avoidance of certain medications to reduce morbidity and mortality. Recent research focusing on nonanesthetic or exercise-induced MH has demonstrated a relationship between certain gene mutations and malignant hyperthermia susceptibility. CASE REPORT: We report the case of a 19 year-old man with a family history of MH who was treated for exertional heat stroke, but despite cooling and adequate fluid resuscitation, demonstrated worsening rhabdomyolysis that subsequently responded to the administration of dantrolene sodium. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case illustrates the importance of recognizing the potential relationship between exertional heat stroke and malignant hyperthermia. The overlap between heat stroke and malignant hyperthermia susceptibility has important implications in the treatment and evaluation of patients presenting with signs and symptoms of heat stroke or heat-related illness in the ED.