British Association of Dermatologists' Guidelines for the Management of Alopecia Areata 2012

A.G. Messenger; J. McKillop; P. Farrant; A.J. McDonagh; M. Sladden


The British Journal of Dermatology. 2012;166(5):916-926. 

In This Article

7.0 Diagnosis

The diagnosis of alopecia areata is usually straightforward although the following may cause diagnostic difficulties:

  1. Trichotillomania – this condition probably causes most confusion and it is possible that it coexists with alopecia areata in some cases. The incomplete nature of the hair loss in trichotillomania and the fact that the broken hairs are firmly anchored in the scalp (i.e. they remain in the growing phase, anagen, unlike exclamation mark hairs) are distinguishing features.

  2. Tinea capitis – the scalp is inflamed in tinea capitis but the signs may be subtle.

  3. Early scarring alopecia.

  4. Telogen effluvium.

  5. Anagen effluvium (drug-induced) may mimic diffuse alopecia areata.

  6. Systemic lupus erythematosus.

  7. Secondary syphilis.

Dermoscopy can aid the diagnosis of alopecia areata. Regular round yellow dots are commonly seen in areas of hair loss and can indicate active disease progression. Dermoscopy also highlights common features seen in this condition such as dystrophic hairs with fractured tips (exclamation mark hairs) and hairs fractured before emergence from the scalp (cadaverized hairs). These findings are not present in triangular alopecia, trichotillomania or localized scarring conditions, which are sometimes considered within the differential of alopecia areata.[16] Occasionally, alopecia areata presents as diffuse hair loss which can be difficult to diagnose. The clinical course often reveals the true diagnosis but a biopsy may be necessary in some cases.


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