The same ULBP3 gene also plays an active role in rheumatoid arthritis, celiac disease, and insulin-dependent diabetes mellitus, further confirming the autoimmune nature of AA. ULBP3 gene proteins are not normally present on hair follicles but are abundant in hair follicles affected by AA. It was recently discovered to share common antigen encoded by gene ULBP3. AA is thought to occur after the collapse of the hair follicles’ immune privileged state following an unknown insult, leading to upregulation of MHC I complexes and follicular antigen presentation, which incites a T lymphocyte-mediated immune response to immunologically unfamiliar follicular antigens. While AA is believed to be a TH1 lymphocyte–mediated autoimmune attack of the hair follicle, its pathophysiology is largely unknown. What is the Cause of Alopecia areata?ĪA is thought to be caused by an autoimmune attack of the base of the hair follicle that spares the stem cell compartment of the follicle, so regrowth of hair remains possible. Sixty percent of cases present before 20 years of age 7-37% have familial associations. All races and males and females are affected equally. Who is at Risk for Developing Alopecia areata? ![]() Secondary syphilis presents with a moth-eaten pattern of irregular, diffuse patches of alopecia. Tinea capitis presents as inflamed, scaling patches of alopecia with characteristic black dot hairs (if caused by Trichophyton tonsurans) throughout the patch it is differentiated from AA by KOH microscopic examination and/or fungal cultures. Trichotillomania presents with irregularly-shaped, poorly circumscribed areas of alopecia, with broken hairs present throughout the lesion and a negative hair pull test. In clinically equivocal cases, when a biopsy may be obtained, the histopathology shows an early anagen bulb surrounded by lymphocytic infiltrate resembling a “swarm of bees.”ĪA must be differentiated from trichotillomania, tinea capitis and secondary syphilis.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |