Background: Acne, also known as acne vulgaris, is a long-term skin disease that occurs when hair follicles are clogged with dead skin cells and oil from the skin. It is characterized by blackheads or whiteheads, pimples, oily skin, and possible scarring.
Objective: To evaluate TSH, free T3 and free T4 in patients with acne treated with systemic isotretinoin at baseline and after three months of treatment to find any alteration in TFTs.
Patients and methods: This study was conducted on thirty patients with treatment for acne vulgaris.  The study was done in Al-Azhar university hospitals from June 2018-February 2019.
Results: The mean and standard deviation of age was 30.62 ± (7.6) years. There was no statistical difference in age distribution, i.e. normally distributed. As regard sex, there was 38 (76%) females and 12 (24%) males. The ratio of female to male was 3:1.Serum levels of thyroid function tests were compared by using Wilcoxon comparison test for non-parametric tests. There was a statistically significant difference between both variables. TSH levels markedly elevated in comparison to before treatment. In contrast to TSH levels, T3 and T4 reduced significantly when compared to before treatment levels.
Conclusion: Dermatologists need to be aware about possible TFTs abnormalities during systemic isotretinoin therapy. Clinical symptoms regarding thyroid disease for both hypothyroidism and hyperthyroidism should be evaluated regularly at visits, and patients with concomitant thyroid function disease should be monitored for TFTs.