<unk>  is usually diagnosed based on clinical features. Trichoscopy may aid in establishing the diagnosis. In<unk> , trichoscopy shows regularly distributed "yellow dots" (hyperkeratotic plugs), small exclamation-mark hairs, and "black dots" (destroyed hairs in the hair follicle opening). Oftentimes, however, discrete areas of hair loss surrounded by exclamation mark hairs is sufficient for clinical diagnosis of<unk> . Sometimes, reddening of the skin, erythema, may also be present in the balding area. A biopsy is rarely needed to make the diagnosis or aid in the management of<unk> . Histologic findings may include peribulbar lymphocytic infiltration resembling a "swarm of bees", a shift in the anagen-to-telogen ratio towards telogen, and dilated follicular infundibulae. Other helpful findings can include pigment incontinence in the hair bulb and follicular stelae. Occasionally, in inactive<unk> , no inflammatory infiltrates are found. Classification Commonly,<unk>  involves hair loss in one or more round spots on the scalp. * Hair may also be lost more diffusely over the whole scalp, in which case the condition is called diffuse<unk> . *<unk>  monolocularis describes baldness in only one spot. It may occur anywhere on the head. *<unk>  multilocularis refers to multiple areas of hair loss. * Ophiasis refers to hair loss in the shape of a wave at the circumference of the head. * The disease may be limited only to the beard, in which case it is called<unk>  barbae. * If the person loses all the hair on the scalp, the disease is then called<unk>  totalis. * If all body hair, including pubic hair, is lost, the diagnosis then becomes<unk>  universalis.<unk>  totalis and universalis are rare.
Alopecia areata
Hair loss
Alopecia mucinosa
Trichotillomania
Alopecia universalis
Alopecia totalis
Loose anagen syndrome
Alopecia neoplastica