Skin Acidity Level in Children with Atopic Dermatitis

Abstract

Background: Atopic dermatitis (AD) is a chronic, relapsing, and pruritic inflammatory skin disease commonly found in children. It is characterized by a complex and multifactorial pathogenesis involving genetic, immunologic, and environmental factors. One of the proposed pathomechanisms includes mutations in the filaggrin gene, which plays a crucial role in maintaining epidermal barrier integrity, skin hydration, and regulating skin surface acidity or potential of hydrogen (pH). Alterations in skin pH have been associated with barrier dysfunction, increased susceptibility to infection, and worsening of inflammation in AD patients. Objective: To analyze and compare the skin pH in children with AD, specifically between lesional and non-lesional areas. Methods: This was a cross-sectional analytical study conducted from January to April 2024 at the Pediatric Dermatology Division, Department of Dermatology, Venereology, and Aesthetic Medicine, and the Allergy and Immunology Division, Department of Pediatrics, Dr. Soetomo General Academic Hospital, Surabaya, Indonesia. Skin pH was measured in both lesional and non-lesional areas. Lesional measurements were performed on areas presenting with erythema and/or lichenification. Results: A total of 33 patients were enrolled in the study. The mean skin pH of lesional areas was 5.92 ± 0.45, while that of non-lesional areas was 5.38 ± 0.42. Statistical analysis showed a significant difference in pH values between lesional and non-lesional skin (p = 0.001). A subgroup analysis comparing erythema and lichenified/hyperpigmented lesions revealed no significant difference in pH values (p = 0.102). Conclusion: In children with AD, the skin pH of lesional areas is significantly higher than that of non-lesional areas.