Abstract
A 25-year-old woman repetitively manifested subcutaneous painful indurated nodules on the sites of insulin injection. She had type 1 diabetes mellitus and was treated at the Department of Endocrinology and Metabolism. Her symptom was suspected as amyloidosis, and she was referred to our department for further examination. She presented 19 painful subcutaneous indurated nodules of 2 to 5 cm in diameter on the abdomen, which was suspected as insulin ball firstly. However, the subcutaneous nodules also occurred at the site of only one injection .Therefore, suspecting insulin allergy, drug lymphocyte stimulation test was perfomed. The test revealed positivity for insulin glargine U 300 and insulin degludec. The patient was diagnosed with insulin allergy. She was treated with topical betamethasone butyrate propionate. Alteration of the fast-acting insulin from lispro-aabc to aspart and the long-acting insulin from glargine U300 to degludec reduced the number of indurated nodules decreased and improved pain.
