Patch and Photo Patch Test in Facial Melanosis

Dr. Shruti Shubham, Dr. Anant Khandelwal, Dr. Md Raihan

Abstract: Introduction: Facial melanosis is a common skin condition with multifactorial causes, including genetic, environmental, hormonal, and inflammatory factors. Allergic and photoallergic contact dermatitis are emerging as key contributors to hyperpigmentation. Patch and photo patch testing aid in identifying allergen-induced pigmentation, enabling targeted treatment. This study assesses the role of these tests in detecting contact and photoallergic triggers in facial melanosis. Methodology: This two-year prospective observational study at the Dermatology Department, Rama Medical College, involved 355 patients with clinically diagnosed facial melanosis. Patch and photo patch testing were done using the Indian Standard Series (ISS), including allergens like fragrances, preservatives, sunscreens, and hair dyes. Patch tests were read at 48 and 96 hours; photo patch tests at 24 and 48 hours after UVA exposure (5 J/cm?). Data were analyzed using SPSS v20 with Chi-square tests and logistic regression. Results: Patch testing identified 46.48% positive reactions, with 28.48% also showing photo patch positivity, highlighting the role of photoallergic mechanisms. The most common allergens were fragrances (25.07%), preservatives (19.44%), and sunscreen agents (15.77%). Fitzpatrick skin type V (30.99%) was the most affected. Occupational analysis revealed indoor workers (29.58%) and housewives (21.13%) had high allergen exposure. Moderate sun exposure (41.97%) was most common, indicating non-UV-dependent pigmentary changes in many cases. Conclusion: Patch and photo patch testing are crucial in diagnosing allergic and photoallergic contributors to facial melanosis. Identifying and avoiding allergens improves treatment outcomes. Future studies should explore long-term effects of allergen avoidance and develop hypoallergenic skincare alternatives for patients at risk.

Keywords: Facial melanosis, Allergic contact dermatitis, Photoallergic contact dermatitis, Patch testing, Hyperpigmentation

How to Cite?: Dr. Shruti Shubham, Dr. Anant Khandelwal, Dr. Md Raihan, "Patch and Photo Patch Test in Facial Melanosis", Volume 14 Issue 8, August 2025, International Journal of Science and Research (IJSR), Pages: 570-575, https://www.ijsr.net/getabstract.php?paperid=SR25812012737, DOI: https://dx.doi.org/10.21275/SR25812012737