The etiology is unknown. There is a lymphocytic infiltration around the hair follicles and the disease is sometimes combined with other autoimmune diseases (e.g. vitiligo, atopic dermatitis), so it is now thought that there may be an autoimmune pathogenesis to the development of the disease. Genetic quality is also an important factor and may be associated with HLA type II, with a family history in 25% of cases. In addition, it may be associated with neurotrauma, psychiatric abnormalities, infectious lesions and endocrine disorders.
Clinical presentation
It can occur at any age, but is more common in young adults, with no significant difference in incidence between the sexes. The lesions appear as round or oval non-scarring alopecia, with “exclamation point” like hairs often visible at the edges of the baldness. Total or almost total hair loss is called alopecia areata. If all the hair on the body (including body hair) is lost, it is called alopecia universalis. Creeping alopecia is also seen. The skin of the diseased area is not abnormal except for the absence of hair.
Sometimes there may be nail abnormalities, the most common being nail depression, as well as brittle nails, nail peeling, and anterior nail. It can also be complicated by ocular cataracts, Down syndrome, thyroid disease and vitiligo.
Differential diagnosis
It needs to be differentiated from tinea capitis, scarring alopecia, traction alopecia, syphilitic alopecia, and androgenetic alopecia.
Treatment
Most common baldness has a tendency to heal naturally, but a few cases occur repeatedly, so treatment is difficult. However, there are many therapies that can be combined to treat hair loss.
1.Topical medication
(1) Minoxidil 5% minoxidil cream or solvent, applied 1 or 2 times a day, may be related to its vasodilator effect.
(2) anthralin 0.5% to 1% anthralin ointment or cream, is a primary stimulant. It is applied topically 1 to several times a day, to the extent that it causes mild local skin dermatitis.
(3) Contact sensitizer Diphenylcyclopropenone (DCP) is most commonly used.
(4) glucocorticoids strong hormone topical or sealing package. 0.05% dexamethasone, 50% dimethyl sulfoxide solution for external use often has better efficacy than creams, etc.
2.Internal medicine
(1) Glucocorticoids
Prednisone is taken internally and gradually reduced after a few weeks, and then maintained in small doses for 6 months. Glucocorticosteroids are effective, but they have many side effects and are prone to recurrence after stopping, so they are not used as conventional therapy. However, for acute baldness, it can be tried to avoid the development of total baldness or general baldness.
(2) Cyclosporine The course of treatment is 6 to 12 months. It is effective in some cases, but if it has no effect after 4 months, it can be stopped.
(3) Thymopentin Intramuscular injection for 3 weeks.
(4) Vasodilators Niacin is taken orally.
3.Local injection method
Local injection of glucocorticoids is suitable for a smaller range of hair loss, or important cosmetic areas (such as eyebrows) in patients with alopecia areata. It can be injected directly into the hair loss area, or into its peripheral part, in order to control the continued expansion of the hair loss. Care should be taken to avoid local skin atrophy and depression that may be caused.
4.Nerve closure therapy
After the nerve is closed, the temperature of the skin in the area of its innervation rises, which is conducive to hair regeneration.