Reactive angioendotheliomatosis as a side effect of long-acting injectable insulin use

A 44-year-old woman with type II diabetes mellitus presented with an 8-month history of a painful, ulcerating rash at the area of insulin injection of her left lower abdomen. Topical antibiotics, topical corticosteroids, oral antibiotics, and supportive wound care provided no relief. A similar eruption developed on the right abdomen when she switched injection sites. Wedge biopsy of the violaceous, reticular plaque demonstrated a central dermal scar with surrounding lobular and linear collections of small blood vessels, consistent with reactive angioendotheliomatosis. This condition typically occurs secondary to an underlying systemic disease, but we believe hers was a side effect related to trauma from insulin injection or secondary to an insulin additive hypersensitivity. The patient was switched to a glucagon-like peptide-1 agonist, active lesions were treated with topical timolol 0.5% ophthalmic solution, and oral propranolol was started with upward titration. She continues to see improvement in pain and has not developed any new ulcerations at other sites on the body.