Epidemiology of molluscum contagiosum in children: a systematic review.

BACKGROUND Molluscum contagiosum (MC) is a common skin condition that primarily affects children, a common reason for presenting in primary care and is commonly seen in children presenting with other conditions in primary and secondary care. It is usually asymptomatic but can present with pain, pruritus, erythema and bacterial superinfection. Aim. To synthesize the current epidemiology of MC. Design and setting. A systematic literature review of bibliographical databases on the prevalence, incidence, risk factors, age distribution and association with other conditions for MC in children. RESULTS Data on the epidemiology of MC is largely of poor quality. The largest incidence is in children aged between 0 and 14 years, where the incidence rate ranged from 12 to 14 episodes per 1000 children per year. Incidence rates in the UK were highest in those aged 1-4 years. Meta-analysis suggests a point prevalence in children aged 0-16 years of between 5.1% and 11.5%. There is evidence for an association between swimming and having MC and MC is more common in those with eczema; however, there is little evidence for other risk factors. CONCLUSIONS MC is a common condition, with the greatest incidence being in those aged 1-4 years. Swimming and eczema are associated with the presence of MC, but the causal relationships are unclear. There is a lack of data regarding the natural history of MC and published data are insufficient to determine temporal or geographic patterns in incidence, risk factors, duration of symptoms or transmission between family members.