Histopathologic Study of Dermatophytosis

Kim, Sung Wook; Kim, Si Yong; Cho, Baik Kee

Abstract

BACKGROUND: Dermatophytosis is sometimes difficult to diagnose deinitively if it has atypical clinical characteristics and mycological tests are negative. Histopathologic findings may be different depending upon the location and causative dermatophytes.
OBJECTIVE
The purpose of the present study was to evaluate histopathologic characteristics nf dermatophytosis depending upon the areas of involvement.
METHODS
We evaluated the clinical and histopathologic features of 32 cases of dermatophytosis which were diagnosed by skin biopsies at the Dermatology Department of branch hospitals of Catholic University Medical College from March 1985 to August, 1994. Histopathologic features were observed in three dilferent groups divided by location, area of terminal hair, areas of vellus hair and hairless areas.
RESULTS
Epidermal changes including hyperkeratosis, parakeratos, acanthosis, spongiosis and neutrophilic exocytosis were frecuently observed in the three groups of Iermatophytosis. In 7 cases of tinea capitis and linea barbae, follicular and inflamma or changes of the deep dermis were important. Hyphae and spores were observed in 71%(5 cases) and 57%(4 cases) respectively, in the follicles. In 19 cases of tinea faciale, tiriea corporis and tinea cruris, change epidermis and superficial dermis as well as findings of follicular infundibulum were important. Herphae were observed in 84%(16 cases) and 53%(10 cases) in the stratum corneum and vellus hir follicle respectively, and in 3 cases the hyphae were observed only in the vellus hair follicle. Sandwich sign, known to be important clue of dermaliophytosis, was observed in only 5%(1 cacse, In 6 cases of tinea manus and linea pedis, hyphae and spores were rebserved in 100% (6 cases) and 33%(2 cases) respectively, in the stratum corneum.
CONCLUSION
We consider tha histopathologic observations may of great help to diagnose some difficult cases of dermatophytosis and the presence of hyphae n .he vellus hair follicle may be a more frequent and important finding than the sandwich sign the dermatophytosis of the vellus hairy regions.