Alopecia Areata with Lymphocytic Mural Folliculitis Affecting the Isthmus in a Thoroughbred Mare
August 2004
in “
Veterinary Dermatology
”
TLDR The horse had a rare type of hair loss caused by immune cells attacking hair follicles.
A 13-year-old thoroughbred mare exhibited multifocal, generalized, noninflammatory alopecia for 8 years and more recent alopecia, erythema, and scaling on the forehead and muzzle. Histopathological examination revealed lymphocytic inflammatory infiltrate around anagen hair bulbs, indicating alopecia areata. A biopsy from the forehead showed atrophic hair follicles with perifollicular and mural mononuclear folliculitis at the isthmus. Immunohistochemical staining confirmed T-lymphocytic origin of the infiltrate. The simultaneous lymphocytic infiltration at both bulbar and isthmic levels in the same horse was an unusual finding, suggesting a variation in the histological presentation of alopecia areata.
