BACKGROUND. Localized drug-induced injection site reactions are rare. Injection site sclerodermoid reactions have been reported as a result of multiple drugs, most commonly vitamin K. Sclerodermoid injection site reactions have also been reported with pentazocine, progestin, and vitamin B12. Little has been written on the efficacious treatment of this complication. OBJECTIVE. The objective was to raise awareness of the potential complication of localized sclerodermoid change secondary to vitamin B12 injections and to present a novel approach to its treatment. METHODS. We report a case and review the English literature for injection site reactions from vitamin B12 as well as treatment options for this complication.

We report the first non-European case of localized sclerodermoid reaction secondary to vitamin B12 injections. Our patient presented with disfiguring depression of the left upper arm following vitamin B12 injections for macrocytic anemia secondary to Crohn's disease. Histopathology showed findings similar to those seen in localized scleroderma. The patient was successfully treated with excision of diseased skin, local fat transfer, and complex repair with dramatic improvement at 5 months in contour and overall appearance.