Impact of isotretinoin therapy on thyroid hormone levels in acne vulgaris: A prospective study

Acne vulgaris (AV) is a common dermatological condition characterized by inflammatory and noninflammatory skin lesions. Isotretinoin (IOS), a systemic retinoid, is widely recognized for its efficacy in managing severe AV due to its potent anti-inflammatory and sebosuppressive properties. IOS interacts with nuclear receptors belonging to the steroid-thyroid hormone superfamily. While its therapeutic benefits are well-documented, the potential effects of IOS on thyroid function remain inadequately explored. This study aims to evaluate the impact of IOS therapy on thyroid hormone levels in patients with AV. This prospective study included 50 patients with AV who were prescribed 0.5 to 1 mg/kg/day of IOS treatment for 4 months. Thyroid function was evaluated by measuring serum levels of triiodothyronine, thyroid-stimulating hormone, and thyroxine at the beginning and post-IOS treatment period. Posttreatment analyses revealed a significant increase in thyroid-stimulating hormone levels and a substantial decrease in triiodothyronine and thyroxine levels compared to baseline measurements (P<.000). These findings suggest that IOS therapy may influence thyroid hormone synthesis and regulation. IOS may induce subclinical changes in thyroid function. Monitoring thyroid parameters during therapy is recommended. Further research with larger sample sizes and controlled designs is warranted to better understand the mechanisms underlying these associations and their clinical implications.