Contact dermatitis risk in acne patients undergoing systemic isotretinoin treatment

Aim: Systemic isotretinoin, 13-cis retinoic acid (13-cRA) is an effective and safe treatment for severe acne. However, it has some side cutaneous effects such as decreased sebum secretion and disruption of epidermal barrier along with some immunomodulatory effects like enhancing antigen presenting activity of epidermal Langerhans cells (LC) and T-cell activity. Since both epidermal barrier and the immunological status are important for the development of allergic and irritant contact dermatitis, we aimed to show the sensitisation and irritation risks among patients with acne under 13-cRA therapy. Materials and methods: The study consisted of 65 severe to refractory acne patients. European standard patch test series was used to screen the sensitisation and irritation reactions of the patients before and after completion of 3 months of 13-cRA treatment. Results: Patch test results revealed an increase in newly-formed sensitisation and irritation reactions. While no statistical difference was detected in the irritation percents, sensitisation percent was significantly higher (43.1%) in the second patch test when compared to the first test results (27.7%) (p=0.002). Conclusion: This study has revealed that the sensitisation percent for some allergens is higher after the 13-cRA treatment. It can be explained by disrupted barrier function which allows for greater antigen penetration and/or the upregulation of antigen-presenting activity in LC which may cause a more prominent immune reaction. Although a small number of patients, since 13-cRA may have a sensitiser effect, a higher contact dermatitis risk should be considered during the treatment and further studies are needed on the subject.