Clinical features

Presentation is typically with localised, round bald patches developing suddenly over one or two weeks, without any preceding symptoms.

Most commonly involved areas include:

• scalp
• eyebrows
• eyelashes
• beard

During the active disease at the edge of the patch, there may be small, broken hairs with a tapering shaft - 'exclamation mark' hairs. (1)

Hair loss can take many forms ranging from loss in well-defined patches to diffuse or total hair loss, which can affect all hair bearing sites (1)

• patchy alopecia affecting the scalp is the most common type
• alopecia areata affects nearly 2% of the general population at some point during their lifetime.

The scalp shows no sign of inflammation, scaling or scarring.

Round, demarcated, bald and smooth areas can be seen on the scalp or within the facial hair (1).

There might be associated itching, burning, or tenderness in these patchy areas. Finger nails changes affect around 10-30% of people with alopecia areata. Changes may be seen before, during or after an episode of hair loss.

The finger nails may be pitted and ridged and nail pitting is seen in 10% to 66% of patients with the condition. (2)

Reference:

1. Darwin E, Hirt PA, Fertig R, et al. Alopecia Areata: Review of Epidemiology, Clinical Features, Pathogenesis, and New Treatment Options. Int J Trichology. 2018 Mar-Apr;10(2):51-60.

2. Hordinsky MK. Medical treatment of noncicatricial alopecia. Semin Cutan Med Surg. 2006;25:51-55.