Authors: Dr Achala Liyanage, Dermatology Fellow, Waikato Hospital, Hamilton, New Zealand; Assoc Prof Patrick Emanuel, Dermatopathologist, Auckland, New Zealand. January 2015.
Demodicosis is caused by two species of follicular mites, Demodex folliculorum and Demodex brevis, which are normal inhabitants of human skin. Although the mites are ubiquitous on sebaceous-rich skin, they sometimes cause dermal reaction and consequent erythema, pustules, and inflammatoryplaques.
Histology of demodicosis
Microscopically, demodicosis has follicular and perifollicularchronicinflammation with follicular dilatation and dense homogenous eosinophilic material surrounding the mites. There can be granulomatous tissue reaction.