Pressure-Induced Alopecia: Presence of Thin Hairs as a Trichoscopic Clue for the Diagnosis

Abstract

Pressure-induced alopecia (PA) is an unusual pattern of circumscribed hair loss that occurs after ischemic changes on the scalp. Trichoscopic findings described in the literature are scarce, nonspecific, and include black dots, broken hairs, circle hairs, and erythema. However, we report 3 cases of PA in which trichoscopy also showed many vellus and thin hairs. Possibly, the maintenance of these hair shafts may be explained by the more superficial insertion of their bulbs on the skin and/or their lower metabolic rates, making them suffer less from local hypoxia. Therefore, the authors suggest that these relevant signs should be added as a clue for the diagnosis of PA in doubtful cases.

Traction Alopecia

“…[ 24 ] All the studied patients were using elastic bands together with a pony tail in adult females and braiding in pediatric patients, which is consistent with the aforementioned hair styling causality. [ 1 14 ] The clinical pattern of marginal (frontal, temporopareital occipital, or mixed) hair loss was predominant in 96.6%, while non-marginal diffuse hair loss seen in one (3.3%) case. TA is a "biphasic" disease with early non-scarring and reversibility, whereas in chronic state there is scarring and permanent hair loss.…”

“…Traction alopecia (TA) is a type of hair loss due to repetitive traction and tension on the hair. [ 1 ] The main risk factors for TA are associated hair care practices and not hair types. The applied trauma is often unintentional and usually secondary to cultural, social, religious, and occupational practices given known associations with grooming accessories and particular hairstyles.…”

“…The applied trauma is often unintentional and usually secondary to cultural, social, religious, and occupational practices given known associations with grooming accessories and particular hairstyles. [ 1 2 3 4 ] High-risk hairstyling practices include tight buns, ponytails, pigtails, chignons, braids, cornrows, and dreadlocks; application of weaves, braids, or hair extensions to relaxed hair; and any hairstyles that cause pain, crusting, tenting, or folliculitis. [ 1 2 ]…”

“…[ 1 2 3 4 ] High-risk hairstyling practices include tight buns, ponytails, pigtails, chignons, braids, cornrows, and dreadlocks; application of weaves, braids, or hair extensions to relaxed hair; and any hairstyles that cause pain, crusting, tenting, or folliculitis. [ 1 2 ]…”

Black dots in trichoscopy after COVID‐19. Can it be telogen effluvium?

“…PA is a term used to describe a group of scarring and nonscarring alopecias that often occur following hospitalization in intensive care units. 3 …”