Introduction:
Atopic dermatitis (AD) is a chronic and recurrent disease with an inflammatory background. Genetic and environmental factors are responsible for the occurrence and development of this dermatosis.

Objective:
The aim of the study was to assess the frequency of colonisation of the nasal vestibule and apparently healthy skin by S. aureus, and to assess dermal lesions for superinfection with S. aureus in AD patients.

Material and methods:
The research was performed on a population of 100 AD patients. Three smears were collected for microbiological investigations: from the anterior nares, from apparently healthy skin and from lesioned skin. On collection, the material was cultured on mediums provided by the bioMerieux and Argenta companies. The strains were identified and their sensitivity to antibiotics assessed by means of the Vitek2 system (bioMerieux).

Results:
S. aureus was present in at least one location in 90%. 44% presented S. aureus colonization of apparently healthy skin and within skin lesions. In the case of 23%, this particular pathogen was detected only in skin lesions, whereas 6% had a positive result within the area of apparently healthy skin. In total, S. aureus was detected in the skin of 73%. In 61%, apparently healthy skin had been colonized with S. aureus, whereas in 81% colonization was proved within the skin lesions. S. aureus was detected in the nasal vestibule of 85%. Among the group with S. aureus in their anterior nares, the pathogen was also found on the skin surface of 77%.

Conclusions:
S. aureus colonises skin in most AD patients. Most AD patients carry S. aureus in their nasal vestibules. S. aureus does not seem to colonise healthy skin as often as skin lesions in young people. The vast majority of S. aureus strains were sensitive to local antibiotics. Most S. aureus strains produced penicillinase.