Systemic allergic dermatitis caused by cobalt and cobalt toxicity from a metal on a metal hip replacement.

The article presents a case report of an 84-year-old woman with a orthopaedic history who experienced generalized pruritic eczematous rash. She had undergone a metal-on-metal (MoM) right total hip replacement for a fractured femur neck in May 2009. Skin biopsy of the rash revealed urticarial features with no overt histological evidence of a drug eruption. Diagnosis of the patient revealed systemic allergic dermatitis (SAD) caused by cobalt.