Exogenous ochronosis in melasma: A study from South India

Abstract

Background: Exogenous ochronosis (EO) can be associated with the prolonged application of hydroquinone (HQ) used for the treatment of melasma. Histopathological examination is required for a definite diagnosis. Dermoscopy can be used to avoid unnecessary biopsies from the face. Aims and Objectives: The aim was to characterize the clinical profile of melasma, to elicit the dermoscopic features of melasma and EO if any, and to histopathologically confirm any suspected cases of EO. Materials and Methods: This was a descriptive study spanning October 2011 to June 2013. With informed consent, a detailed history and examination was carried out along with details of skin lightening creams used if any. This was followed by cutaneous examination and dermoscopic evaluation. In those who had lesions suspicious of EO, consent for 3 mm punch biopsy was obtained and the samples were studied using hematoxylin and eosin stain for banana-shaped ochre colored fibers. Results: In 104 (94 females, 10 males), the mean age at onset and duration of melasma was 36.6 and 4.14 years, respectively. Past history of treatment for melasma was present in 30.8% patients. The most common clinical type of melasma was malar (51.9%). EO was suspected in five patients. In suspected cases, brown-blue globules were noted in addition to melasma features dermoscopically. Telangiectasias were noted in 37.5% of patients. Histopathological confirmation of EO was obtained in only one out of four patients who gave consent for biopsy. Conclusion: The frequency of EO in our study was found to be 0.9%. The incidence of EO in Indian population appears to be quite low, which might be due to under reporting, lack of awareness, irregular and infrequent use of HQ or population based difference in prevalence.