Pattern of Bacterial Colonization of Atopic Dermatitis in Saudi Children

Background: Atopic dermatitis is an inflammatory skin disorder. Although it is not a life threatening condition, it may become infected with microorganisms, especially in children. Objectives: The aim of this study was to determine bacterial colonisation in children with atopic dermatitis. Methods: A total of 80 children were randomly included in this study. Two swabs were taken from each child, one from the eczematous skin lesion and the other from apparently healthy skin, as a control. Bacteria were isolated and identified on the basis of the colonial morphology, gram staining and the Vitek System. Results: The mean age of children in this study was 1.4 years, with no gender difference (p=0.98) (n=80). A total of 240 bacterial colonies were grown from atopic dermatitis lesions in contrast to 193 colonies from non-lesional skin. Gram-positive cocci were found in 78 (97.5%) lesions and in 77 (96.2%) non-lesional skin. Staphylococci species were significantly detected in the lesions than in the non-lesional skin. Ent. Faecalls, Ent. Faecium, Ent. gallinarium and C. minutissium were significantly isolated from lesions as compared to non-lesional skin, whereas C. xerosis was insignificantly found to be more in the lesions (p=0.21). Gram-negative bacteria were isolated from 7(8.8%) lesions, but none were isolated from non-lesional skin. Recovered species were Pantoea agglomerans, Enterobacter cloacae, Chryseobacterium indologenes and Acinetobacter lwoffii. Conclusion: Atopic dermatitis in children is complicated with streptococcal and gram-negative bacterial colonisations and the latter was correlated with the severity of the lesions. Enterococci and Corynebacterium species were significant residents. S. aureus remained the chief inhabitant. No causal relationship could be established between the skin microbiota and atopic dermatitis.