Work

First case of hyperpigmentation in vitiligo after use of methimazole in a patient with Graves' disease

Year: 2025

Type: article

Abstract: First case of hyperpigmentation in vitiligo after use of methimazole in a patient with Graves' disease ଝ Dear Editor,A 50-year-old man was seen at the endocrine outpatient clinic at Hospital das Clínicas (Universidade de São Paulo) due to hyperthyroidism in November 2020, referred by the cardiology team, which started methimazole 15 mg/day two months before.The patient had a 6-year history of generalized vitiligo, untreated for 3years.The physical examination had no hyperthyroidism signs, thyroid enlarged on palpation, without nodules.The skin showed depigmented macules and patches involving scalp, face, neck, forearms, dorsal hand, fingers, feet, and trunk, with some hyperpigmentation in the vitiligo macules periorbital and in the scalp (Fig. 1A).Based on thyroid function tests and thyroid ultrasound (moderately hypoechoic gland without nodules, volume of 26.33 cm 3 and increased vascularization), the diagnosis of Graves' disease was given.Laboratory tests before methimazole: Thyrotropin (TSH) < 0.008 IU/mL, serum Free T4 (FT4) 4.99 ng/mL, total Triiodothyronine (T3) 438 ng/mL, high Thyrotropin Receptor Antibody (TRAb) 3.88 IU/L, and thyroglobulin antibody undetectable.In February 2021, while using methimazole, the patient was concerned about recent pigmentation, started two months after initiating methimazole.He denied redness, burning, itching, or other associated symptoms.On physical examination presented multiple scattered brown, welldemarcated macules, and patches in sun-exposed areas (ears, scalp, forehead, periorbital), darker than the normal surrounding skin, sparing areas covered by a face mask, used for protection against SARS-CoV-2 infection (Fig. 1B).Most of the other vitiligo lesions had some perifollicular repigmentation.Laboratory tests showed TSH < 0.02 IU/mL, FT4 1.85 ng/mL, T3 169 ng/mL, and TRAb 2.27 IU/L.

Source: Anais Brasileiros de Dermatologia

DOI: 10.1016/j.abd.2024.06.006

Authors: Nicolau Lima, Meyer Knobel, Mayara Chinelatto, Maria Victória Quaresma

Institutions: Universidade de São Paulo, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Universidade de Ribeirão Preto

Language: English

Topic: Thyroid Disorders and Treatments

Subfield: Endocrinology, Diabetes and Metabolism

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $1,700