An unexpected complication of folk medicine: Acute bullous irritant contact dermatitis due to topical onion oil

Topical folk remedies are widely used for musculoskeletal complaints despite their potential cutaneous adverse effects. We report a 60-year-old woman who developed severe burning, erythema, and tense bullae on the lower back 6 hours after applying pure onion oil (Allium cepa) for chronic low back pain. Acute bullous irritant contact dermatitis was diagnosed based on the rapid onset and sharply localized distribution. The patient showed marked clinical improvement with substantial re-epithelialization within 20 days following appropriate wound care and topical treatment. This case highlights the potential dermatological hazards of unsupervised herbal remedies and emphasizes that natural products should not be considered inherently harmless.