Nickel dermatitis from an infusion needle

An obese 19-year-old woman, with a personal and family history of atopy had known sensitivity to nickel since the age of 12 years. She has had insulinresistant diabetes for 6 years, with one hyperglycaemic coma and two hypoglycaemic comas. An insulin infusion pump (Atrapid M. C. Medi) was fitted 6 months previously; this consists of a 5 ml syringe operated by a disposable batterY, and a subcutaneous butterfly needle in the abdomen. I month after the pump had been fitted, itchy papules appeared round the needle site and they increased to form a plaque 10 cm in diameter. Topical treatment with corticosteroids had no effect. 4 months later, the papules had spread over the abdomen ana buttocks with intense itching which was worse at night. Patch tests with the GEIDC standard series gave the following positive results: cobalt chloride, nickel sulphate and cobalt sulphate. With a special metal series, the only positive results were: tin chloride 1 % aq. and copper sulphate 1 % aq. The needle was analysed using an Erax Phillips electron microscope, coupled to a computer programmed for metals, and found to be stainless steel, with 8 % nickel. This needle was not attracted to a magnet and no cobalt, tin or copper was detected. A dimethylglyoxime test on the needle was negative (1-3). The stainless steel needle was replaced by a Teflon one and the clinical signs completely disappeared within 15 days.