Demodex folliculorum and Demodex brevis are two mites which infest the human eye and which may, in excess, lead to a wide range of anterior segment findings. Demodex mites have been implicated in anterior and posterior blepharitis, blepharoconjunctivitis, blepharokeratitis, and beyond. Due to significant overlap with other anterior segment conditions, Demodex infestation remains underdiagnosed and undertreated. Definitive diagnosis can be made with lash sampling, and the most common mode of treatment is with tea tree oil in varying concentrations. This article summarizes elements of pathogenesis, diagnosis, and management critical to clinical care of this common condition.
Keywords: Demodex brevis; Demodex folliculorum; blepharitis; blepharoconjunctivitis; meibomian gland dysfunction; ocular rosacea.