Alopecia is characterized by excessive hair loss of more than 100 per day. Affected individuals may complain of pruritus, and burning sensation in that area. The pattern of hair loss is mostly to the sides, and lower back region of the scalp. Alopecia totalis occurs with complete loss of hair on the scalp. Alopecia universalis is defined as total hair loss on all the hair bearing areas of the body. The occurrence of alopecia can be focal or diffuse in pattern.
Yellow spots are the clinical signs of alopecia, which are reported in few cases. Other clinical presentations are broken hair, clustered short and tapering hair. In long standing cases of alopecia the phase of telogen hair reaches to 100% . Individuals with alopecia also undergo psychological distress, due to excessive loss of hair that affects their cosmetic appearance.
The following methods are employed for diagnosing alopecia.
Alopecia is a benign condition. Treatment has a little or no role in preventing this condition to recur. Remissions and reoccurrences are seen in most of the cases. Methods employed for treating alopecia help in arresting further hair loss, and has little effects in hair regrowth  .
Alopecia can predispose an individual to develop psychological problems. The prognosis of the condition is poor; however hair loss is arrested, with medications and topical ointments to manage symptoms . But, new hair growth occurs at a slower pace.
The exact cause of alopecia is unknown. However, several factors such as febrile illnesses, pregnancy, trauma, drugs, chemotherapy and autoimmune conditions, can trigger an episode of hair loss. Individuals with family history of alopecia are at increased risk of developing the same.
Alopecia can also be associated with certain conditions like Down syndrome, Collagen vascular diseases, vitiligo, atopic dermatitis and thyroid disease. In few patients, a gene DQ3 is found that could be responsible for the predisposition of this condition. In some studies, Interleukinin 1 and tumor necrosis factor were found to play an important role in inhibiting hair growth .
Males and females are equally affected. Alopecia can occur at any age, but its peak incidence is seen from 15 to 29 years of age. Several other abnormalities like koilonychia, onycomedesis and Beau lines are common abnormalities of nails, seen in individuals with alopecia. Frequency of involvement from high to low is as follows, scalp, beard, eyebrows, and extremities .
The hair growth cycle follows 3 distinct phases, anagen, catagen and telogen phase. The anagen is the growing phase, followed by short transitional phase, and then resting phase which is known as telogen. After the telogen phase, hair fall occurs, and new hair begins to grow in the follicles again. Under normal circumstances, about 40 to 100 hair fall each day, which is natural. However, when the number exceeds more than 100, then it is termed as clinical hair loss – tellogen effluvium .
Alopecia cannot be prevented. However, the underlying disease conditions should be promptly treated to stop aggravating the condition .
Alopecia is hair loss, which can exhibit many patterns in appearance. It is a medically benign condition, but can also cause psychological distress to the subject, and his family. The onset of alopecia is mostly in the early years of life. Patients may find themselves depressed and stressed due to this condition .