RESUMEN
Intralesional triamcinolone acetonide injection is indicated for multiple skin conditions such as keloid scars, alopecia areata, and hypertrophic lichen planus. Immediate hypersensitivity reaction remains uncommon. We report on a 24-year-old woman who had received multiple intralesional injections with triamcinolone acetonide (Kenacort) plus lidocaine for keloid scar treatment without any reaction for the previous 10 years. The immediate reaction occurred 15 minutes after injection, with numbness on her face and 5 minutes later with urticaria on her chest wall and upper extremities, together with hypotension (blood pressure of 90/60 mmHg). Allergology workup revealed positive skin prick test for triamcinolone acetonide (Kenacort). Skin tests for other corticosteroids (hydrocortisone, methylprednisolone, and dexamethasone), excipients (carboxymethylcellulose, benzyl alcohol, and polysorbate 80) and lidocaine were negative, including subcutaneous challenge for lidocaine and oral challenge for carboxymethylcellulose. IgE-mediated hypersensitivity reaction must be considered in cases of multiple applications of triamcinolone acetonide injection.