BACKGROUND: The pathogenesis of atopic dermatitis is still unknown, but house dust mites are thought to be playing an impor tant role in the development of skin lesions. Atopic dermatitis shows an immediate react,ion to mite allergens in skin prick test, postive IgE-FAST for mite antigens, and higer serum levels of mite-specific IgG4, IgE and IgE immune complexes. This immediate antigen-IgE-initiated reaction, however, is not clinically and histologically relevant to typical skin lesion, eczematization. OBJECTIVE: We tried to show that atopic skin lesions can clinically be induced by the type 1V hypersensitivity to house dust mites and evaluate the histological features of the eczematous skin lesions. METHODS: We investigated patch test reaction to Dermatophagoides farinae and the changes of expression of intercellular adhesion molecule 1(ICAM 1), vascular cellular adhesion molecule 1(VCAM 1), and E selectin on vascular endothelial cells in skin biopsies obtained from positive patch sites. RESULTS: Positive rate is 41%. The patch test has a good correlation with asthma predisposition. In the positive reaction sites, the expression of ICAM 1 is markedly increased, and those of VCAM 1 and E selectin are induced on the vascular endothelial cells. CONCLUSION: D. farinae patch testing represents a diagnostic method besides prick testing in mite induced eczematous dermatitis but better standardization is necessary. D. farinae can activate the endothelial cells and enhance the expression of adhesion molecules, so allergic contact sensitivity to mite allergen is playing an important role in the pathogenesis of atopic dermatitis.
Allergens ; Antigen-Antibody Complex ; Asthma ; Biopsy ; Cell Adhesion Molecules* ; Cell Adhesion* ; Dermatitis, Atopic* ; Dermatitis, Contact ; Dermatophagoides farinae* ; E-Selectin ; Eczema ; Endothelial Cells ; Humans ; Hypersensitivity ; Immunoglobulin E ; Immunoglobulin G ; Mites ; Patch Tests* ; Pyroglyphidae* ; Skin

A 13-year-old girl developed rice to nut-sized, bluish to slate-gray colored, depressed patches in a zosteriform distribution along the right side of her upper back and arm without any symptoms. Microscopically, the lesions showed a normal-appearing epidermis, dermis, and subcutaneous fat tissue except for a thinning of collagen fibers and widening of intervals between them in the lower dermis. There have been no changes to the skin lesions during the last 2 years.
Adolescent ; Arm ; Collagen ; Dermis ; Epidermis ; Female ; Humans ; Skin ; Subcutaneous Fat