Demodex-associated folliculitis.

Examination of 388 follicles in 24 large resections of skin for the presence of histologic folliculitis and Demodex mites uncovered a nonrandom association between these two phenomena. Demodex mites were found in 42% of follicles with inflammation, but in just 10% of the follicles without inflammation. Eighty-three percent of follicles with Demodex showed inflammation. The probability that this result could occur by random chance alone was < 0.001, thus suggesting that Demodex is associated with histologic folliculitis, even minor folliculitis. The results do not, however, decide whether Demodex is causative, whether it preferentially selects follicles with histologic inflammation, or whether some of both processes operate.