title: Molluscum contagiosum and associations with atopic eczema in children: a retrospective longitudinal study in primary care.
abstract: BACKGROUND
  Molluscum contagiosum (MC) is a common skin condition in children. Consultation rates and current management in primary care, and how these have changed over time, are poorly described. An association between the presence of atopic eczema (AE) and MC has been shown, but the subsequent risk of developing MC in children with a diagnosis of AE is not known.
  
  
  OBJECTIVE
  To describe the consultation rate and management of MC in general practice in the UK over time, and test the hypothesis that a history of AE increases the risk of developing MC in childhood.
  
  
  METHODS
  Two studies are reported: a retrospective longitudinal study of MC cases and an age-sex matched case-cohort study of AE cases, both datasets being held in the UK Clinical Practice Research Datalink from 2004 to 2013.
  
  
  METHODS
  Data of all recorded MC and AE primary care consultations for children aged 0 to 14 years were collected and two main analyses were conducted using these data: a retrospective longitudinal analysis and an age-sex matched case-cohort analysis.
  
  
  RESULTS
  The rate of MC consultations in primary care for children aged 0 to 14 years is 9.5 per 1000 (95% CI = 9.4 to 9.6). The greatest rate of consultations for both sexes is in children aged 1-4 years and 5-9 years (13.1 to 13.0 (males) and 13.0 to 13.9 (females) per 1000 respectively). Consultation rates for MC have declined by 50% from 2004 to 2013. Children were found to be more likely to have an MC consultation if they had previously consulted a GP with AE (OR 1.13; 95% CI = 1.11 to 1.16; P<0.005).
  
  
  CONCLUSIONS
  Consultations for MC in primary care are common, especially in 1-9-year-olds, but they declined significantly during the decade under study. A primary care diagnosis of AE is associated with an increased risk of a subsequent primary care diagnosis of MC.
authors.affiliation: Institute of Health and Wellbeing, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Olsen
authors.affiliation: Professor and head of Department of Dermatology and Academic Wound Healing, Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff.
authors.forename: Vincent
authors.initials: V
authors.lastname: Piguet
authors.affiliation: Department of Psychiatry, Medical Sciences Division, University of Oxford, Oxford.
authors.forename: John
authors.initials: J
authors.lastname: Gallacher
authors.affiliation: Cochrane Institute of Primary Care and Public Health, School of Medicine, Cardiff University, Cardiff.
authors.forename: Nick A
authors.initials: NA
authors.lastname: Francis
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008976:Molluscum Contagiosum / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D011320:Primary Health Care / Q000379:methods*; D012017:Referral and Consultation; D012189:Retrospective Studies; D006113:United Kingdom / Q000453:epidemiology
keywords: atopic eczema; children; consultation rates; molluscum contagiosum; primary care