In dermatology, the medical term used for hair loss is alopecia. The condition may be an isolated problem or connected with other condition or disease. For example, quite often alopecia is associated with scalp disease or scarring. Depending on the condition, hair loss may be either a temporary or permanent issue. Any kind of hair loss reduces individual’s quality of life and causes psychosocial problems.
Hair loss affects any individual at any age with any hair type or hair colour. Hair loss can result from multiple causes.
As hair grows in cycles (anagen – growth, thelogen – rest, catagen – shedding) the affected cycle often gives a name of the hair loss.
Anagen hair loss is caused due to decreased hair growth. Telogen hair loss is caused due to increased hair in rest phase with subsequent shedding. Other causes are congenital or acquired abnormalities of hair shaft, presence of inflammatory skin disease which can negatively affect the hair bulb as well as changes from thick terminal hair to think vellus hair.
The features of hair loss vary with the cause. Itch and soreness are absent except when hair loss is caused due to inflammatory skin disease. Burning and picky discomfort are common symptoms for hair shedding.
Anagen hair loss occurs when hair starts to be tapered and/or broken off. The duration of the condition varies with each individual. Children can be affected as well by anagen hair loss when they have normal hair but it cannot grow their hair longer. In adults, the anagen shedding occurs in sudden onset. Empty follicles and short broken hairs are common features. The common causes are presence of autoimmune disease, side effects from medications (chemotherapy and cytotoxic drugs), and inheritance of this condition from parents. If anagen hair loss is caused by medications, the hair growth may return back to normal after 3-6 months of withdrawal from medications.
Telogen hair loss refers to excessive hair shedding. The condition becomes visible after 2-6 months after the event that stopped the active growth of hair. Some of these events include psychological stress, illness, surgical operation, fever, weight loss, child-bearing, haemorrhage, and medications (anticonvulsants, anticoagulants, or contraceptives).
Hair shaft abnormalities can be inherited and congenital or caused by disease or injury. In the current context, injuries refer to hair bleaching, chemical usage, hair dryer hear, excessive brushing, and hair pulling. Some of the common features are fractures, irregularities, coiling, and twisting.
Hair loss can also be caused due to systemic diseases, such as syphilis, iron deficiency, or thyroid hormone deficiency. Similarly, hair loss can be caused due dermatological disease like generalised skin disease (erythroderma), localised infection (tinea capitis), or severe skin disease (atopic dermatitis, psoriasis, cutaneous T-cell lymphoma). This results reversible hair thinking, bald patches, and reduced quality of hair.
Hair loss diagnosed by full skin examination and patient’s history. Dermatologists also perform additional tests to confirm their diagnosis. For example, hair pull test may be done to test anagen and telogen hairs. Swabs can be done for checking for presence of bacterial and viral culture. Blood tests may be requested for haematology, thyroid function, and serology analysis.
Treatment for hair loss vary with each patient and unique to each case. Infections should be treated. Causative drugs may be advised to be discontinued. Any deficient like iron and thyroid hormone should be remedied.
Majority of hair loss conditions cannot be actively prevented. However, there are some recommendations to follow that will prevent the injuries of hair shaft: using loose hairstyles to avoid traction injuries, minimizing usage of chemical treatments, and drying hair naturally or setting hair dryer on cool setting to avoid damage from heat.