Implant-associated Metal Hypersensitivity Presenting as Psoriasiform Dermatitis

Abstract

Metal hypersensitivity reactions to orthopedic implants are uncommon but may present with persistent and treatment-resistant cutaneous manifestations. We report a 39-year-old male who underwent stainless steel implant fixation of the right ulna, femur, and hip following polytrauma sustained in a road traffic accident. Four years after implantation, he developed pruritic, scaly psoriasiform plaques over the surgical sites that gradually disseminated to the contralateral elbow, knee, and both legs. The lesions showed temporary improvement with systemic and topical corticosteroids but repeatedly relapsed during tapering, resulting in steroid dependence and complications, including obesity, Cushingoid features, and vascular changes. Dermoscopic findings were suggestive of psoriasis. However, histopathological examination revealed preservation of the granular layer, favoring psoriasiform dermatitis. Patch testing demonstrated sensitivity to nickel sulfate and potassium dichromate. Given the relapsing course and positive sensitization, staged removal of the implants was performed. Complete and sustained resolution of the lesions occurred following implant removal without further need for immunosuppressive therapy. This case highlights the importance of considering implant-induced hypersensitivity in patients with refractory psoriasiform eruptions localized to metallic implant sites, as definitive management may require removal of the offending implant.