Anogenital Contact Dermatitis in Spain: A <scp>REIDAC</scp> Study of Patients Undergoing Patch Testing in 2019–2024

Abstract

ABSTRACT Background The REIDAC (Spanish Registry for Research in Contact Dermatitis) conducts nationwide epidemiological surveillance of contact dermatitis in Spain. Anogenital involvement within REIDAC has not been previously studied. Objectives To describe the most common diagnoses and update relevant allergens in patients with anogenital lesions referred for patch testing. Methods We analysed patients who underwent patch testing within REIDAC from 2019 to 2024. Patients were classified into three groups: (G1) exclusively anogenital lesions, (G2) no anogenital involvement and (G3) both anogenital and non‐anogenital lesions. Sensitisation and relevance were assessed. Results Among 18 291 patients, 116 (0.6%) had exclusively anogenital lesions, 17 576 (96.1%) had no anogenital involvement and 599 (3.3%) had both. G1 patients were more likely to have at least one positive reaction (91.4%), a current relevant reaction (53.4%, diagnosed with allergic contact dermatitis, ACD) and to be polysensitised compared to other groups ( p &lt; 0.001). 14.5% of anogenital ACD identified cases were not identified by the Spanish baseline series. Fragrances, preservatives, topical anaesthetics and steroids were the leading relevant allergens. Benzisothiazolinone, sodium metabisulfite and propolis emerged as new sensitisers. Conclusion ACD was highly prevalent among patients with anogenital lesions referred for patch testing. The threshold for patch testing in these patients may need reconsideration.

Affiliated Institutions

• Hospital Universitari Sagrat Cor ES
• Universidad de Las Palmas de Gran Canaria ES
• Spanish Academy of Dermatology and Venereology ES
• Universidad de Sevilla ES
• Hospital Universitario Virgen de la Arrixaca ES
• Hospital Universitari i Politècnic La Fe ES
• Complejo Hospitalario Universitario de Toledo ES
• Instituto de Investigación Biosanitaria de Granada ES
• Hospital Universitario de Fuenlabrada ES
• Hospital Universitario Puerta de Hierro Majadahonda ES
• Hospital Universitario Infanta Sofía ES
• Hospital Universitario Fundación Alcorcón ES
• Hospital de Sant Pau ES
• Hospital Universitario 12 De Octubre ES
• Universidad Europea ES
• Universitat Pompeu Fabra ES
• Hospital Universitario Insular de Gran Canaria ES
• Hospital Universitario Araba ES
• Hospital Universitari Germans Trias i Pujol ES
• Hospital Universitario Rey Juan Carlos ES
• Hospital Universitario Virgen del Rocío ES
• University of the Basque Country ES
• Hospital Universitario Ramón y Cajal ES
• Hospital General Universitario Morales Meseguer ES
• Hospital General Universitario de Alicante Doctor Balmis ES
• Hospital General Universitario De Valencia ES
• Hospital Universitario Fundación Jiménez Díaz ES
• Universitat Autònoma de Barcelona ES
• Complejo Hospitalario Universitario de Santiago ES
• Hospital Arnau de Vilanova ES
• Complejo Asistencial Universitario de Palencia ES
• Hospital Universitario de La Princesa ES

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