1Zaghloul W, 2Abdel-Khabir
A and 2El-Sohafy M
Departments
of 1Microbiology & Immunology and 2Dermatology &
Andrology, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
Forty two patients
with atopic dermatitis (AD) and twenty age and sex matched healthy subjects
were included in the present study. Swabs from lesional skin and anterior nares
were taken and cultured for identification of bacteriological growth. S. aureus
strains isolated from both skin and nose were investigated for superantigen
production (Enterotoxins A-D) by reverse passive latex agglutination (RPLA)
test. Results of bacteriological culture revealed that the incidence of S.
aureus colonization in patients skin (71.4%) was significantly higher than
in control group (30%) and the colonization was more significant in patients
with wet lesions than those with dry lesions. There was no significant
difference in the nasal carrier between patients (45.2%) and control group
(40%). As regards the superantigen production, 53.3% of S. aureus
strains (38.1% of the total cases) were found to secrete enterotoxins, mainly Staphylococcal
enterotoxin B and C (SEB and SEC) while in the control group only 33.3% of isolated
S aureus strains (10% of the total group) were enterotoxins producers.
Treatment of 16 cases with topical steroids alone for one week resulted in
reduction of S. aureus colonization by 62.5% and enterotoxins production
by 60%. In conclusion, skin lesions of AD are frequently colonized with
superantigens producing strains of S. aureus. These superantigens could
act as a trigger or exacerbating factor in the pathogenesis of atopic
dermatitis. Topical steroid therapy, significantly reduced colonization of
superantigens producing S. aureus in
skin lesions of atopic dermatitis and induced clinical improvement.