Cicatricial and Noncicatricial Alopecias



Cicatricial and Noncicatricial Alopecias


Paul Curtiss

Kumar Sukhdeo

Kristen I. Lo Sicco

Jerry Shapiro




OVERVIEW

Alopecia refers to a reduction or complete loss of hair in an otherwise hair-bearing area. As discussed later, the etiology of alopecia is primarily divided between nonscarring (noncicatricial) and scarring (cicatricial) processes. These diagnoses are non-mutually exclusive, and multiple patterns may evolve in the same patient. Careful history taking and examination by an informed practitioner is essential in establishing the correct diagnosis and dictating management. Particular attention should be maintained in evaluating for cicatricial alopecias because permanent hair loss may occur if misdiagnosed or delayed. Although alopecias are not life-threatening, a profound link exists between hair growth and patients’ self-perception. To this end, alterations in normal hair patterns drive many clinic visits and can have devastating psychological impact on patients’ quality of life.


NONCICATRICIAL ALOPECIAS: ALOPECIA AREATA


BACKGROUND

Alopecia areata (AA) is a common, nonscarring alopecia characterized by an autoimmune attack on the hair follicle. It affects approximately 0.1% to 0.2% (1.7% lifetime
risk) of individuals in the United States, with a spectrum of hair loss ranging from a small isolated patch of hair loss, multiple focal patches of hair loss (patchy alopecia), complete scalp hair loss (alopecia totalis [AT]) to universal body hair loss (alopecia universalis [AU]).1


PRESENTATION

Patients present with a history of the recent sudden appearance of patches of hair loss on the scalp or beard.



PATHOGENESIS

AA is an autoimmune disease with a strong genetic component; there is 50% concordance in monozygotic twins and one-third of patients having an affected family member. Several pathoetiologic mechanisms have been implicated, including loss of immune privilege of the follicle site, T-cell overactivation, and inappropriate antigen presentation by HLA/MHC complex subtypes.3 Hashimoto hypothyroidism is the most frequently associated autoimmune disease, occurring between 8% and 24% of patients with AA. Less commonly AA has also been associated with vitiligo, Down syndrome, Addison disease, and autoimmune recessive polyglandular syndrome (APS-1).4





Jun 29, 2020 | Posted by in Dermatology | Comments Off on Cicatricial and Noncicatricial Alopecias

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