RESUMO
BACKGROUND: Isotretinoin is widely used in the treatment of acne. AIMS: We investigated the effects of isotretinoin on thyroid function tests and thyroid volume in acne patients. METHODS: In this prospective study, a total of 104 acne patients were included. Sixty-six patients were treated with isotretinoin for at least 4 months. Thirty eight patients were included in the control group. The levels of thyroid stimulating hormone, free triiodothyronine, free thyroxine, antithyroglobulin and antithyroid peroxidase antibodies were measured and a thyroid ultrasound was performed in all the subjects before treatment and 4 months after treatment. A "p" value of < 0.05 was considered significant. RESULTS: In the isotretinoin-treated group, thyroid stimulating hormone levels increased significantly during isotretinoin treatment (P = 0.018). Free triiodothyronine, free thyroxine, anti-thyroid peroxidase levels and thyroid volume decreased significantly during treatment (P = 0.016, P= 0.012, P= 0.006, P = 0.020 respectively). LIMITATIONS: The major limitation of this study is the lack of follow-up data after the cessation of isotretinoin therapy in acne patients. CONCLUSION: Patients treated with isotretinoin should be monitored with thyroid function tests.