Child of steel

Abstract

Allergic reactions to metal implants have been on the rise reaching an incidence of 10-17% in the general population. In Asia, nickel ranks among the top five most common source of metal sensitivity. We present a case of nickel allergic contact dermatitis secondary to an orthopaedic implant. 12/M with chronic osteomyelitis of the left tibia presented with non-union of the bones necessitating an Ilizarov fixator implant using conventional SAE 16 stainless steel plate and bone graft. After 9 months, there was paucity of the bone allograft necessitating adjustment of the Ilizarov fixator and repeat bone allograft. 2 weeks after the second revision of the metal implant, the child manifested with pruritic wheals on both his flanks lasting for a week. Months later, the wheals developed along the pin tracts with serous exudate. Orthopaedics entertained a possible hypersensitivity to the metal implant and the fixator was removed. For further work-up, the child was referred to dermatology and allegro-immunology service whereupon further history revealed that he has a prior undocumented allergy to metal accessories when he was 6 years old. A patch test was later performed revealing +1 reaction to nickel. Failure of the union of the left tibia and decreasing function of the left leg necessitated a below-knee amputation and subsequent application of a prosthetic limb. This is a rarely reported case of metal implant allergy in a pediatric patient presenting as failure in wound healing and non-union of tibial fracture. This case further emphasizes the importance of a complete medical history in assessing a patient with possible metal allergy and its proper diagnosis and management. This case also highlights the possible role of metal exposure and the patient’s chronic infection in the pathogenesis of bone non-union.