title: Allergic contact angioedema to benzoyl peroxide.
abstract: Benzoyl peroxide (BP) is commonly used for topical acne treatment and has long been known to be a weak allergen and a strong irritant. We report a case of a 26-year-old woman, who presented with an itchy erythematous reaction and strong oedema localized to the face. Two weeks before angioedema, the patient had started a new topical treatment with a gel containing 10% BP for acne. She was patch tested to European Standard Series, including BP 1% in white petrolatum, and to the 10% BP-containing gel previously used by herself, showing positivity on day 2 to BP 1% and to the 10% BP-containing gel. Factors that suggested an association between the severe angioedematous reaction and BP topical application include the strong reaction to BP in the patch-test, the temporal relationship, the complete resolution of symptoms after the drug was withdrawn and the absence of other identified explanations.
authors.affiliation: Division and School of Allergy and Clinical Immunology, Department of Human Pathology, University of Messina, Messina, Italy.
authors.forename: P L
authors.initials: PL
authors.lastname: Minciullo
authors.forename: M
authors.initials: M
authors.lastname: Patafi
authors.forename: L
authors.initials: L
authors.lastname: Giannetto
authors.forename: B
authors.initials: B
authors.lastname: Ferlazzo
authors.forename: D
authors.initials: D
authors.lastname: Trombetta
authors.forename: A
authors.initials: A
authors.lastname: Saija
authors.forename: S
authors.initials: S
authors.lastname: Gangemi
mesh_terms: D000152:Acne Vulgaris / Q000188:drug therapy; D000328:Adult; D000799:Angioedema / Q000139:chemically induced*; D001585:Benzoyl Peroxide / Q000009:adverse effects*; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D010328:Patch Tests
chemical_list: D001585:Benzoyl Peroxide