Trichoscopic findings in alopecia areata- a cross sectional study

Introduction

Alopecia areata (AA) is a common non scarring alopecia affecting 0.1-0.2 percent of general population of all races.^[1] It usually presents as well circumscribed patches of sudden hair loss. It can affect males and females of any age and in many cases a family history of AA itself or other autoimmune disorders is present. Patients with AA have higher than expected incidence of thyroid disease, vitiligo and atopic eczema.^[2], ^[3], ^[4]

Clinical diagnosis of AA is not challenging but at times it may be confused with other patchy alopecias like Tinea capitis, Trichotillomania, Telogen effluvium etc. Moreover the activity and severity of the disease can not be assessed clinically. Trichoscopy reveals specific patterns in AA and can be an aid to diagnose, assess severity and disease activity in AA.

Trichoscopic findings in AA may differ depending on disease activity, severity and duration of the disease. Black dots, dystrophic and fractured hair, exclamation mark hair (EMH) are the most specific findings in AA and are indicative of abrupt anagen alterations and correlate with strong and ongoing disease activity. While yellow dots may be observed in all stages of both acute and chronic alopecia areata, short re-growing hair indicate a better prognosis.^[5]

Materials and Methods

The study was a cross sectional observational study conducted in the Department of Dermatology, Venereology and Leprosy, R.D.Gardi Medical College and C.R. Gardi Hospital, Ujjain (M.P.), between January 2017-December 2018. Male and female patients of clinically diagnosed Alopecia areata between the age group of 18-50 years were included after taking informed consent. Hair loss due to external injury, chemotherapy or any drugs and systemic illness and hair shaft disorders were excluded.

In every patient a detailed history was elicited and recorded on a proforma, and relevant clinical examination was performed, following which trichoscopic examination was performed using a DINOLITE digital microscope system with adjustable polarization flexible LED system equipped with a video camera with lenses providing magnifications ranging from 20X to 220X.

Results

A total of 122 patients with AA were enrolled including 76 males and 46 females. The mean age of presentation was 30.46 years. 80 (65.5%) patients were between the age group of 20-40 years. Majority (95%) of the patients presented within 6 months of the onset of alopecia areata. On trichoscopy Yellow dots were the most common trichoscopic findings observed in 108 (88.5%) patients followed by short vellus hair 66 (54.1%), short regrowing hair 58 (47.5%), exclamation mark hair 56 (45.9%), black dots 44 (36.1%) and broken hair 34 (27.9%).

Discussion

Yellow dots, first proposed by Ross et al.^[6] are seen as yellow colored round or polycyclic dots, which represent follicular infundibulum, distended with degenerating keratinocytes and sebum. Yellow dots are the most common and most sensitive feature of alopecia areata. In a study conducted by Inui et al.^[7], yellow dots were seen in 63.7% of cases in contrast to Ross et.al. study ^[6] where 94.8% cases with alopecia areata had yellow dots . Similarly a study from North India by Chiramel et al^[8] found 87.5% patients of alopecia areata with yellow dots. In our study yellow dots were observed in 88.5% patients. In a study by Naveen et al^[9] in South India, the yellow dots were found in 57.33% of patients. The low incidence may be attributed to the skin color of South Indian patients which make the yellow dots difficult to visualize. Although characteristic of alopecia areata, yellow dots are also seen in androgenetic alopecia, discoid lupus erythematosus, dissecting cellulitis of scalp etc.^[5]

Exclamation mark hair (EMH) is a broken hair with a dark, frayed, thick tip. Its proximal portion is thin and hypopigmented. EMH are typical of alopecia areata and represent peribulbar lymphocytic activity leading to thin hair production. They are co-related with disease activity.^[10] In 2014, Ankad et al.^[11] also reported them to be the sign of active disease.^[11] EMH were seen in 30% 31.7% of cases by Inui et al ^[7] and Ankad et al.^[11] respectively.

Dystrophic or broken hair (BH) correlates with disease activity. In our study broken hair were seen in 27.9% of the cases. BH were observed in varying proportions from 30% to 75% in various published studies.^[7], ^[8], ^[11]

Black dots (BD) are seen within the yellow dots and represent broken pigmented hair (cadaverized hair), that are fractured before emerging from the scalp due to severe inflammatory process or a tractional trauma.^[12] Numerous black dots are found in patients with AA. Previous studies have shown BD ranging from 20% to 77%.^[7], ^[8], ^[11] In our study BD were seen in 36.1%.

Short vellus hair (SVH) represent hair re-growth. They appear as either short, upright, tapered regrowing terminal hairs of normal thickness or as thin coiled “pig tail” hair. SVH were seen in 54.1% of cases of AA in our study. Our findings were consistent with studies by Chiramal et al ^[8] (50%) and Thappa et al ^[13] (40.9%).

Conclusion

Trichoscopy is a rapid and non invasive tool which can be reliably used to diagnose and assess the severity and disease activity in Alopecia areata. Hence a trichoscopic evaluation should be done in every case of AA.

Source of Funding

None.

Conflict of Interest

None.