title: Melasma: a clinico-epidemiological study of 312 cases.
abstract: BACKGROUND
  Melasma is an acquired increased pigmentation of the skin, characterized by gray-brown symmetrical patches, mostly in the sun-exposed areas of the skin. The pathogenesis is unknown, but genetic or hormonal influences with UV radiation are important.
  
  
  OBJECTIVE
  Our present research aims to study the clinico-epidemiological pattern and the precipitating or provocation factors in melasma.
  
  
  METHODS
  A total of 312 patients were enrolled for the study over a period of one year.
  
  
  RESULTS
  The mean age of patients with melasma was 33.45 years, ranging from 14 to 54 years. There was female preponderance with a female to male ratio of approximately 4 : 1. The mean age of onset was 29.99 years, with the youngest and oldest being 11 and 49 years, respectively. The patients sought medical treatment on an average of 3.59 years after appearance of melasma. About 55.12% of our patients reported that their disease exacerbated during sun exposure. Among 250 female patients, 56 reported pregnancy and 46 reported oral contraceptive as the precipitating factors. Only 34 patients had given history of exacerbation of melasma during pregnancy. A positive family history of melasma was observed in 104 (33.33%) patients. Centrofacial was the most common pattern (55.44%) observed in the present study. Wood light examination showed the dermal type being the most common in 54.48% and epidermal and mixed were seen in 21.47% and 24.03% of the cases, respectively. We tried to find an association with endocrinal diseases and observed that 20 of them had hypothyroidism.
  
  
  CONCLUSIONS
  The exact cause of melasma is unknown. However, many factors have been implicated in the etiopathogenesis of this disorder. Here we try to identify the causative factors and provocation to develop melasma.
authors.affiliation: Department of Dermatology, Midnapore Medical College, West Bengal, India .
authors.forename: Arun
authors.initials: A
authors.lastname: Achar
authors.forename: Sanjay K
authors.initials: SK
authors.lastname: Rathi