**7. Diagnosis**

**6. Prognosis**

110 Hair and Scalp Disorders

Younger age of onset Family history

Associated autoimmune disease

**Table 1.** Poor prognostic factors.

Atopy Ophiasis Nail changes

and universalis may occur in 5–10% of patients [3].

**Figure 3.** Reticular type alopecia areata with a net-like pattern.

Extent of involvement (alopecia totalis/universalis)

The disease has an unpredictable course; spontaneous regrowth of hair is common as observed in about 80% of patients within one year [25]. However, patients usually present with several episodes of hair loss and hair regrowth during their lifetime [8]. Progression to alopecia totalis Diagnosis of alopecia areata is made on clinical grounds. No routine laboratory investigations are needed. Routine thyroid screening is not indicated but screening may be performed in long-standing cases, females, patients with persistent patches, and patients with alopecia totalis and universalis [8].

Upon examination, exclamation mark hairs may be observed within or at the periphery of the lesions that are short hairs tapered towards their base [1]. Exclamation mark hairs occur only in acute forms of alopecia areata and are not seen in patients with long-standing areas of hair loss [15]. Pull test can be performed to assess disease activity; six hairs or more shed from the periphery of the lesion positively correlates with the disease activity [16].

Severity of the disease can be measured by SALT score, developed by the National Alopecia Areata Foundation working committee. The scalp is divided into 4 parts, the top constituting 40% of total surface, the posterior 24%, right side and left side of scalp 18% each. Percentage of hair loss in each area is determined and is multiplied by the percentage of scalp covered in that area of the scalp, and summing the products of each area will give the SALT score [26].

Several studies have shown that dermoscopy may be a useful tool to help in the diagnosis of alopecia areata. Dermatoscopic findings reported in the literature include: yellow dots, black dots, short vellus hairs, black dots, tapering hairs, and broken hairs [27].

In ambiguous cases, a scalp biopsy is required. Histopathological examination of 4 mm punch biopsy containing subcutaneous fat is necessary to establish correct diagnosis. Biopsy should be taken from the periphery of the lesion as this is the site where the disease activity is found [28]. Horizontal sections will give a better representation of the histopathology especially in bulb infiltration than vertical sections [29].
