Parting Thought Journal of Cosmetic Dermatology, 0, 1--5

Evaluation of autoimmune thyroid disease in melasma Majid Rostami Mogaddam, MD,1 Manouchehr Iranparvar Alamdari, MD,2 Nasrollah Maleki, MD,3 Nastaran Safavi Ardabili, MD,4 & Selma Abedkouhi, MD1 1

Department of Dermatology, Imam Khomeini Hospital, Ardabil University of Medical Sciences, Ardabil, Iran Department of Internal Medicine, Imam Khomeini Hospital, Ardabil University of Medical Sciences, Ardabil, Iran 3 The Persian Gulf Marine Medicine Biotechnology Research Center, Department of Endocrinology, Bushehr University of Medical Sciences, Bushehr, Iran 4 Department of Midwifery, Ardabil Branch, Islamic Azad University, Ardabil, Iran 2

Summary

Melasma is one of the most frequently acquired hyperpigmentation disorders clinically characterized by symmetrical brown patches on sun-exposed areas. To date, few studies have been conducted about the relationship between thyroid autoimmunity and melasma. To evaluate the thyroid dysfunction and autoimmunity in nonpregnant women with melasma. A total of 70 women with melasma and 70 agematched healthy women with no history of melasma were enrolled in the study. We studied the thyroid hormone profile in both groups. The statistical analysis was performed using SPSS software. Patients with melasma had 18.5% frequency of thyroid disorders, and 15.7% had positive anti-TPO, while subjects from the control group had a 4.3% frequency of thyroid abnormalities, and only 5.7% had positive anti-TPO. There was a significantly higher prevalence of thyroid dysfunction in women with melasma compared with control group (P = 0.008). This study suggests that there is a relationship between thyroid autoimmunity and melasma. However, to make recommendations on screening for thyroid disease in patients with melasma, future research of good methodological quality is needed. Keywords: melasma, thyroid function test, autoimmunity

Introduction Melasma, also known as chloasma, is a common, acquired disorder, characterized by symmetric, hyperpigmented patches with an irregular outline that affects sun-exposed areas of skin, most commonly the face. It is most prevalent among young to middle-aged women who are Hispanic, Asian, or of African or Middle Eastern descent, that is darker skin phototypes.1 The precise pathogenesis of melasma has not been Correspondence: Nasrollah Maleki, Specialist of Internal Medicine, The Persian Gulf Marine Medicine Biotechnology Research Center, Department of Endocrinology, Bushehr University of Medical Sciences, Bushehr, Iran. E-mail: [email protected] Accepted for publication February 4, 2015

© 2015 Wiley Periodicals, Inc.

determined. However, multiple factors are likely to be implicated in its etiopathogenesis, including pregnancy, combined oral contraceptive pills (OCPs), genetics factors, sun exposure, use of cosmetic products, thyroid dysfunction, and antiseizure medications.1–4 Melasma in men shares the same clinico-histologic characteristics as in women, but hormonal factors do not seem to play major significant role;5 it is not clear whether hormonal factors play a role in men.5,6 The key role of UV radiation is supported by the fading of lesions during winter months and the distribution pattern of melasma, with the involvement of sunexposed sites and sparing of sites such as the philtrum. Compared to the uninvolved adjacent skin, increased melanin deposition is observed in all layers of the epidermis. An increased number of melanin-containing

1

Thyroid autoimmunity and melasma

. M R Mogaddam et al.

dermal macrophages (melanophages) may also be seen. Epidermal melanocytes are normal to increase in number, and they are enlarged with prominent dendrites.7 Ultrastructurally, lesional melanocytes contain an increased number of melanosomes compared to melanocytes from adjacent “normal” skin. In addition, the mitochondria, Golgi apparatus, and rough endoplasmic reticulum are increased in number or amount. These findings support the theory of hyperfunctional melanocytes, presumably stimulated by UV irradiation or hormones.8 The areas of hypermelanosis are distributed symmetrically in three classic patterns: centrofacial, malar, and mandibular.2 The centrofacial pattern is most commonly observed, with the involvement of the lateral forehead, cheeks, nose, upper lip (sparing the philtrum), and chin. In the malar and mandibular forms, the distribution is more limited, that is cheeks plus nose and mandibular ramus, respectively. In addition to the clinical classification scheme based upon distribution pattern, melasma has also been subdivided into four types based upon its appearance under Wood’s lamp illumination: epidermal, dermal, mixed, and indeterminate.2 Screening for thyroid disease in patients with melasma remains a contentious issue. To date, few studies have been conducted about the relationship between melasma with thyroid autoimmunity. This study was conducted to evaluate the thyroid dysfunction and autoimmunity in nonpregnant women with melasma.

Materials and methods Patients and controls

This study was approved by the Ethics Committee of the Ardabil University of Medical Sciences. This was a prospective cross-sectional study. Patients presenting with melasma to the dermatology outpatient clinic of Imam Khomeini Hospital in Ardabil, Iran, between January 2012 and May 2013 were recruited for the study subjects. In this study, 70 women with melasma, aged 20–50 years, referred to our clinic, and 70 agematched healthy women with no history of melasma as the control group were evaluated. Melasma was diagnosed visually or with assistance of a Wood’s lamp (340–400 nm wavelength). Criteria for exclusion included (1) pregnant women, (2) known cases of pre-existing thyroid disease, (3) the coexistence of serious concomitant illness (e.g., decompensated liver cirrhosis or uremia), (4) the coexistence of other autoimmune diseases, (5) history of drug use

2

that might affect thyroid function (glucocorticoids, lithium, amiodarone, iodide, and octreotide), (6) use of OCP and antiseizure medications, and (7) patients on any hormone replacement therapy. We studied the thyroid hormone levels and antithyroid antibodies in both groups. The results of routine investigations (complete blood and urine examinations, random blood sugar, renal and hepatic profiles, and thyroid function tests) were recorded. A standardized questionnaire was used, and details pertaining to family history, and medical and obstetric history were collected. Body mass index (BMI) and blood pressure were also recorded. Written informed consent was obtained from the participants. Assessment of thyroid function

In this study, free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), and antithyroid peroxidase (anti-TPO) were measured in all women with melasma and healthy controls. Serum FT3 and FT4 were measured by a radioimmunoassay method (Vitros Immunodiagnostic Products; Ortho-Clinical Diagnostics Inc., Rochester, NY, USA). Normal reference ranges for FT3 and FT4 were 0.7– 1.8 ng/mL and 4.5–12.00 lg/dL, respectively. TSH was determined using an immunoradiometric assay (Spectra, Fenzia, Finland). Normal reference range for TSH was 0.4–4.5 lIU/mL. Anti-TPO was measured by enzyme-linked immunosorbent assay (Radim, Rome, Italy). Normal reference range for anti-TPO was

Evaluation of autoimmune thyroid disease in melasma.

Melasma is one of the most frequently acquired hyperpigmentation disorders clinically characterized by symmetrical brown patches on sun-exposed areas...
66KB Sizes 0 Downloads 7 Views