Infestation of the eyelash hair follicle results in easier epilation and more brittle cilia. These mites also serve as vectors of infective elements and interrupt tissue integrity. They have been implicated in meibomian granulomas and are associated with certain dermatologic changes. All reported histologic sections of lid follicles infested with D folliculorum show distention and thickening. Coston claims that less than one half the specimens he observed showed perifollicular lymphocytic infiltration.
Follicular inflammation produces edema and results in easier epilation of the eyelashes.
It also affects cilia construction, and lashes are observed to be more brittle in the presence of demodicosis. Although epithelial hyperplasia associated with follicular plugging often is encountered, dermal changes seldom extend beyond the perifollicular epidermal area. This plugging once believed to be mite excreta, is now known to be epithelial hyperplasia with interspersed layers of lipid. The formation of a collar of tissue around the base of the lashes is observed clinically. This occurs significantly more often in follicles infected with D folliculorum.