Metal sensitivity after TKA presenting with systemic dermatitis and hair loss

Recent problems with metal-on-metal bearings in total hip arthroplasty have highlighted a connection between metal particles and allergic responses. Metal sensitivity associated with total knee arthroplasty (TKA) is less understood and poorly characterized. However, metal sensitivity can lead to TKA failure. Accurate and reliable testing for this phenomenon is elusive; therefore, the diagnosis of metal sensitivity remains one of exclusion. Only skin testing and lymphocyte transformation testing are commonly available to assess hypersensitivity, and neither test is reliable.This article describes a woman who presented with severe whole-body dermatitis and hair loss. After prolonged pain and progressive stiffness, including failed manipulation while under anesthesia and open synovectomy, the patient had a positive skin test, but the lymphocyte transformation test was negative. She was treated for metal sensitivity with TKA revision to nonallergenic components, and all symptoms resolved. One year after revision, she had good range of motion, complete dermatitis resolution, and hair loss restoration.To the authors' knowledge, this is the only report that describes hair loss as a symptom of metal sensitivity secondary to TKA and hair regrowth after revision. The authors now include metal sensitivity in a differential of causes of pain and other unusual symptoms after TKA that are otherwise unexplained.