Bacterial Culture Using Tape Method in Atopic Dermatitis and Non-atopic Dermatitis / 대한피부과학회지

ABSTRACT

BACKGROUND: The role of cutaneous bacterial flora in eczematous dermatitis has been discussed for decades. Areas of active dermatitis in patients with atopic dermatitis(AD) are known to be heavily colonized with Staphylococcus aureus. The density of S. aureus is correlated with the severity of AD. S. aureus is considered to be an exacerbating factor in this disease. The bacterium interferes in the inflammatory process of atopic dermatitis in various ways, among which the ability to release superantigens in a high percentage of clinical isolates is of great importance. OBJECTIVE: The purpose of this study was to evaluate the microbiology of the skin of the patients with AD and non-atopic dermatitis(NAD). We compared bacterial colonization of AD with those of NAD and healthy controls(HC). METHODS: Cutaneous organisms were obtained using Tape method from the worst lesion and uninvolved forearm skin of 30 patients with AD, 25 patients with NAD and 30 individuals as HC. Bacterial growth was examined in aerobic culture and the counts of colony forming unit(CFU) were estimated. The sensitivity to ten antibiotics of the bacteria isolated was also tested. RESULTS: 1.S. aureus colonizations of the eczematous skin were found in 19 of 30 AD patients(63%) and in 9 of 25 NAD patients(36%). The difference between the two groups was statistically significan t(p=0.076, alpha<0.1). 2.In AD patients, the frequencies of S. aureus colonizations revealed 63%(19 of 30) in the lesion and 60%(18 of 30) in uninvolved skin, which were significantly higher than 33%(10 of 30) of HC(p<0.05). 3.The frequency of S. aureus colonizations in the lesions of NAD patients revealed 36%, which was not significantly higher than 33% of HC(p=0.836). 4.Coagulase negative strains of staphylococcus were found in 20 of 30 HC(66%) and 17 of 25(68%) uninvolved skin of NAD patients(68%) compared with 12 of 30 uninvolved skin of with AD(40%). 5.In AD patients with positive nasal colonization with S. aureus, the frequencies of S. aureus colonization in the lesion and uninvolved skin were increased in significance compared with patients with negative nasal colonization(p<0.05). And total counts of CFU in the lesion and uninvolved skin of AD patients were significantly higher compared with HC(p<0.05). 6.Total counts of CFU correlated with severity of dermatitis. CONCLUSION: Colonization of S. aureus was significnatly increased in the skin of AD patients compared with healthy controls. As the severity of the AD lesions increased, the numbers of S. aureus isolated increased. These results support the role of S. aureus in the AD described in the previous reports. Tape method had the advantage of being inexpensive, quick and straightforward to prepare, easy for the clinician to use and was well tolerated by children. It is hoped that the result of this study and the availability of Tape method in the culture of bacteria of the skin will facilitate and promote investigations of pathophysiology and treatment of eczematous dermatitis as well as AD.