Evaluation of the serum zinc level in adult patients with melasma: Is there a relationship with serum zinc deficiency and melasma?

Summary

Background

Melasma is a common acquired hypermelanosis of sun-exposed skin, particularly on the face, which presents as symmetric, light- to gray-brown-colored macules and patches. There are several studies of serum zinc levels in cutaneous disorders. So far, no studies have been carried out to assess the serum zinc level in patients with melasma. The aim of this study is to determine the serum zinc level in patients with melasma compared to healthy subjects.

Materials and methods

A total of 118 patients with melasma and 118 healthy controls were enrolled in this prospective cross-sectional study. The two groups were matched for age and sex. Atomic absorption spectrophotometry was used to measure serum zinc levels. The statistical analysis was performed using SPSS software.

Results

The mean serum level of zinc in melasma patients and controls was 77.4±23.2 μg/dL and 82.2±23.9 μg/dL, respectively (P-value=.0001). Serum zinc deficiency was found in 45.8% and 23.7% of melasma patients and control subjects, respectively. A positive family history of melasma in first-degree relatives was present in 46 (39%) of the cases, and a history of taking oral contraceptive pill was found in 95 (81%) of women with melasma. The aggravating factors for melasma were stated as: sun exposure (11.1%), pregnancy (15.3%), nutrition (2.5%), oral contraceptive pills (18.6%), and emotional stress (5.9%). The malar and centrofacial patterns were seen in 3.4% and 72% of cases, respectively, whereas 24.6% of the patients had both centrofacial distribution and malar distribution, and there was no patient with mandibular pattern. Among patients with melasma, 20.3% had thyroid dysfunction, while in the control subjects, 8.4% had thyroid dysfunction (P=.001).

Conclusion

There is a significant relationship between low levels of zinc and melasma. Zinc deficiency may be involved in the pathogenesis of melasma. Also, treatment with oral zinc supplements can be tried in these patients to see the outcome. However, to make recommendations on screening for zinc deficiency in patients with melasma, future research of good methodological quality is needed.