Alopecia areata is a common cause of sudden onset episodic non-scarring hair loss. Patients can experience a single small coin sized patch or multiple patches. It most commonly occurs over scalp but can involve other areas such as beard, eyebrow, eye lashes and body hair. Skin overlying the patch can be red, itchy or scaly. Sometimes patches may join together to involve whole of the scalp (alopecia totalis) or loss of all body hairs (alopecia universalis). As this disease mostly affects pigmented or black hair so patients can feel that the patch area has suddenly developed white hairs. Nails can also develop roughness in 10-15% of the patients. It can occur in any age group but commonly occurs in less than 40 years of age. Although does not make the patient sick, it can be traumatizing experience for the patient.
It occurs when the body’s own immunity attacks the hair bulb leading to sudden loss of hair. Episode of hair loss might be precipitated after periods of stress. Patients might have some family member who has experienced the same condition but it is not contagious. As it is autoimmune disease, other autoimmune diseases can be associated with this such as hypothyroidism, vitiligo, psoriasis and atopic dermatitis.
Diagnosis of alopecia areata is essentially clinical. Dermoscopic examination can help aid in the diagnosis. Investigations such as fungal culture, biopsy might be required to rule out other causes. Blood tests to rule out other autoimmune diseases can be done.
Patient with small patches can regrow hair without treatment in one year in up to 80% of the cases. In 10-15% of the patients, hair loss can progress to involve the whole of the scalp or body. Prognosis is less favorable in children, patients with extensive hair loss, having history of atopic dermatitis
Single or small patches can be treated with the help of topical or injectable corticosteroids which locally suppresses the immune system which is attacking the hair bulb. Intralesional steroids might have to be repeated after a month if patch has not resolved completely. Other topical medicines can also be given such as minoxidil, anthralin, tacrolimus, vitamin D analogues and topical irritants. If patient has extensive disease or it is not resolving with topical or injectables phototherapy or oral medicines have to be given. Phototherapy can be done after topical application of photo-sensitising agent or after oral ingestion. It can be done with solar light or an ultraviolet light chamber. Oral medicines such as corticosteroids, cyclosporine, methotrexate, apremilast or tofacitinib may be given to control the disease activity. Patients with extensive hair loss can benefit from wearing hairpieces, scarves, wigs or bandanas. Eyebrow tattooing can be used to conceal the loss of eyebrow hairs.