title: Effect of Mycobacterium vaccae on atopic dermatitis in children of different ages.
abstract: BACKGROUND
  Exposure to environmental microorganisms is associated with variations in the prevalence and severity of atopic diseases. We have previously shown that administration of a Mycobacterium vaccae suspension significantly reduced the severity of atopic dermatitis (AD) in children aged 5-18 years.
  
  
  OBJECTIVE
  This study aimed to extend these observations to younger children.
  
  
  METHODS
  Fifty-six children aged 2-6 years with moderate to severe AD were enrolled in a randomized, double-blind, placebo-controlled trial and given one intradermal injection of either killed M. vaccae suspension or buffer solution (placebo). Skin surface area affected and dermatitis severity score were assessed before and 1, 3 and 6 months after treatment.
  
  
  RESULTS
  Although a 38-54% reduction in surface area affected by dermatitis was noted at all time points after M. vaccae administration (P = 0.005), this improvement was not significantly different from that observed in the placebo group. Meta-analysis of this and our previous cohort (97 children aged 2-18 years) showed that M. vaccae was associated with a significant improvement in clinical severity at all ages, whereas within the placebo group, younger but not older children showed a similar improvement.
  
  
  CONCLUSIONS
  Despite a reduction in clinical severity associated with M. vaccae at all ages, no benefit could be found after administering M. vaccae to children with AD aged 2-6 years when compared with placebo. M. vaccae may offer greater benefit in children over 5 years old, whose AD appears less likely to regress spontaneously.
authors: Academic Unit of Child Health, University of Manchester, Booth Hall Children's Hospital, Charlestown Road, Manchester M9 7AA, UK. peter.arkwright@lineone.net
authors: P D
authors: PD
authors: Arkwright
authors: T J
authors: TJ
authors: David
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D001428:Bacterial Vaccines / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000188:drug therapy / Q000473:pathology / Q000628:therapy*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage; D006801:Humans; D008297:Male; D015201:Meta-Analysis as Topic; D009161:Mycobacterium / Q000276:immunology*; D016896:Treatment Outcome; D015164:Vaccines, Inactivated / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000900:Anti-Bacterial Agents; D001428:Bacterial Vaccines; D005938:Glucocorticoids; D015164:Vaccines, Inactivated