title: Etiopathogenetic factors, thyroid functions and thyroid autoimmunity in melasma patients.
abstract: BACKGROUND
  Melasma is a common chronic, acquired pigmentation disorder with a significant impact on the quality of life of patients.
  
  
  OBJECTIVE
  To investigate the etiopathogenetic factors, thyroid functions and thyroid autoimmunity in patients with melasma.
  
  
  METHODS
  Forty-five women with melasma and 45 age-matched healthy women were included in the study group. A detailed history was taken from the patients including triggering factors of melasma. Serum free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), anti-thyroglobulin (AbTG) and anti-thyroid peroxidase (Ab-TPO) were measured and thyroid ultrasonography was performed for each subject.
  
  
  RESULTS
  In 26.7% of patients, pregnancy, in 17.8%, oral contraceptive use and in 13.3%, intense sunlight exposure were the triggering factors. 17.8% of patients had a family history of melasma. FT4, TSH and AbTG levels were significantly higher in the patient group.
  
  
  CONCLUSIONS
  The results suggest that a combination of factors including pregnancy, oral contraceptive use, sunlight and genetic factors often trigger melasma. Thyroid hormones and thyroid autoimmunity may also play a role in the pathogenesis which needs to be proven by further studies.
authors.affiliation: Dermatology Clinic, Ankara Numune Education and Research Hospital, Ankara, Turkey. Head of the Department: Ferda Artüz.
authors.forename: Seray Külcü
authors.initials: SK
authors.lastname: Çakmak
authors.affiliation: Dermatology Clinic, Ankara Numune Education and Research Hospital, Ankara, Turkey. Head of the Department: Ferda Artüz.
authors.forename: Nimet
authors.initials: N
authors.lastname: Özcan
authors.affiliation: Dermatology Clinic, Ankara Numune Education and Research Hospital, Ankara, Turkey. Head of the Department: Ferda Artüz.
authors.forename: Arzu
authors.initials: A
authors.lastname: Kılıç
authors.affiliation: Radiology Clinic, Ankara Numune Education and Research Hospital, Ankara, Turkey. Head of the Department: Bülent Sakman.
authors.forename: Suha
authors.initials: S
authors.lastname: Koparal
authors.affiliation: Dermatology Clinic, Ankara Numune Education and Research Hospital, Ankara, Turkey. Head of the Department: Ferda Artüz.
authors.forename: Ferda
authors.initials: F
authors.lastname: Artüz
authors.affiliation: Department of General Surgery, Ankara University Faculty of Medicine, Ankara, Turkey. Head of the Department: Nezih Erverdi.
authors.forename: Atıl
authors.initials: A
authors.lastname: Çakmak
authors.affiliation: Department of Biostatistics, Faculty of Medicine, Ankara University, Ankara, Turkey. Head of the Department: Yasemin Yavuz.
authors.forename: Kenan
authors.initials: K
authors.lastname: Köse
keywords: etiopathogenesis; melasma; thyroid