A clinicoepidemiological study of eruptive hypomelanosis: A newly described entity

Abstract

Background: Eruptive hypomelanosis is a newly described entity from India characterized by sudden onset of symmetrical hypopigmented macules over the extremities. Only a few cases have been reported till date and the etiology is unknown. Aim: To study the epidemiological and clinical profile of eruptive hypomelanosis. Materials and Methods: A total of 19 cases were seen over a period of 5 months (March–July) and subjected to detailed history and clinical examination. Routine investigations including hemogram, liver and kidney function tests, urinalysis, erythrocyte sedimentation rate, C-reactive protein, HIV, hepatitis B surface antigen, anti-hepatitis C virus antibody, and potassium hydroxide (KOH) examination were carried out in all the cases. Skin biopsy was performed in three patients. Results: All patients were of pediatric age group ranging from 3 to 7 years (average 4.42 years) and had multiple discrete to confluent well-defined, hypopigmented nonscaly macules of size ranging from 2 to 20 mm, mainly distributed symmetrically over extensor aspect of extremities. Majority of the cases (12, 63%) presented in April. Six cases (37.5%) had prodrome symptoms 3 days to 2 weeks preceding the onset of lesions and four (25%) had positive family history. The routine investigations including KOH preparation and wood's lamp examination were normal in all cases. Histopathology of the skin was essentially normal. Lesions began to fade spontaneously after a period of 3–4 weeks resulting in complete/near-complete resolution, making total duration of the illness as 4–9 weeks. Conclusion: Considering the eruptive nature of lesions presenting in pediatric population, clustering of cases in a particular season, spontaneous resolution without active intervention, history of prodrome, and positive family history in some patients, eruptive hypomelanosis can be considered as a viral exanthem. As it can be easily confused with pityriasis versicolor, it is important for the clinicians to be aware of this entity so as to avoid unnecessary treatment.