A full-thickness chemical burn to the hand using formic acid-based anti-wart treatment: a case report and literature review

Introduction: Chemical burns are comparably rare but often result in full-thickness skin defects with frequent involvement of underlying structures. Hands are the most commonly affected injury site and impaired functional outcome is common. We present a case of an unusual chemical burn to the dorsum of the hand of a child secondary to application of a topical anti-wart treatment containing formic acid. Case report: An 11-year-old girl was referred to our outpatient department with a full-thickness injury resulting from a chemical burn having used a topical formic acid solution in the treatment of common warts. On examination, a 20-mm circular full-thickness defect was noted to the dorsum of the hand. The extensor tendons were not involved and there were no signs of infection. She required surgical debridement and local flap coverage. The postoperative recovery was unremarkable. Conclusion: Through a comprehensive literature review, four common topical solutions used in anti-wart treatment were identified to be associated with burns. Together with our case, this highlights the importance of careful patient education in the usage of common topical over-the-counter treatments.