[Nosologic position of demodicidosis in humans].

In 20 patients with rosacea and rosacea-like eruptions Demodex folliculorum mites were found in high numbers within lesional skin. In one patient Demodex folliculorum could be demonstrated in pits and burrows in the epidermis of the scalp. In other instances the mouth parts of the mites were closely related to the follicular epithelium. Recent parasitologic findings showed that in spite of their name (Demodex = "sebaceous worm") the mites derive their nutritive requirements from cellular proteins obtained by epithelial destruction. To clarify the pathogenetic significance of hair follicle mites in man as suggested by these histological findings as well as their known ability to form organisational centers of foreign body granulomas, further epidemiologic and immunologic studies are needed. Topical antiparasitic agents did not offer any therapeutic advantage over traditional preparations used for rosacea and seborrheic dermatitis.