Alopecia Areata 1

Alternative Names

  • AA1
  • Alopecia Universalis
  • AU
Back to search Result
WHO-ICD-10 version:2010

Diseases of the skin and subcutaneous tissue

Disorders of skin appendages

OMIM Number

104000

Mode of Inheritance

Multifactorial

Gene Map Locus

18p11.3-p11.2

Description

Alopecia areata (AA) is a chronic inflammatory condition causing non-scarring type of hair loss that can affect any hair bearing area. It shows a spectrum of severity that ranges from patchy localized hair loss, which can eventually involve the entire scalp (a condition known as alopecia totalis), to the complete absence of hair everywhere on the body (a condition known as alopecia universalis). Unpredictable hair loss is the only noticeable symptom of this disease. However, characteristic nail changes may also associated with hair loss. Patients may recover spontaneously but the disease can follow a course of recurrent relapses or result in persistent hair loss. The age of onset of the disease can be sudden at any age, varying from birth to 80 years; however, the majority (60%) commence before 20 years of age. There is equal distribution of incidence across races and sexes. Alopecia areata may be associated with Down's syndrome and other autoimmune conditions, such as thyroid disease and vitiligo. The lifetime risk of developing the condition has been estimated at 1.7%, making it one of the most common human autoimmune diseases.

Diagnosis is usually made clinically, although a biopsy is diagnostic for this condition. Treatment of this condition aims to the re-growth of hair in affected individuals. Many treatments exist for AA including: intralesional corticosteroid injections, which are widely used in mild disease, topical anthralin, minoxidil, and topical sensitizers, such as squaric acid dibutlyester and diphenyl-cyclopropenone. However, none of these treatments alter the natural history of the disease. On the other hand, there is a high proportion of spontaneous recovery, with 34% to 50% of the patients recovering within 1 year; therefore, not all patients require treatment. Poor prognosis is linked to the presence of other immune diseases, family history of AA, young age at onset, nail dystrophy, extensive hair loss, and ophiasis (AA of the scalp margin). The unpredictable nature of the condition, with apparent improvement followed by deterioration can be causing great psychological distress. Hence, one of the most important aspects of management is counseling the patient and the family members of a young child about the nature and course of the condition as well as the available effective treatments with details of what they involve and their side effects.

Although the exact etiology of alopecia areata is not known, the pathophysiology of it is considered to be T-cell mediated autoimmunity in which the immune system mistakenly attacks the hair follicles that occurs mostly in genetically predisposed individuals. Approximately 20% of affected individuals have a family history of the disease, demonstrating that AA has a genetic component. Multiple loci have been associated with the AA disease which are chromosome 21 (increased incidence in Down's syndrome), major histocompatibility complex, and cytokine and immunoglobulin genes, indicating a polygenic basis. In addition, environmental factors could act as triggers for disease progression in genetically predisposed individuals.

Epidemiology in the Arab World

View Map

Other Reports

Egypt

Mahmoud and Kamal (1998) carried out a prospective study on 84 patients with patchy type of alopecia areata (AA) of < 25% affection during a nine months period (June 96 to February 97), aiming to evaluate the types and the prevalence of nail changes occurring in the patchy type of AA with minimal hair loss. Patients with other variants of AA and those on medications were excluded from the study. Twenty-six patients had other diseases (14 atopic manifestations, 6 psoriasis, 2 vitiligo, 3 diabetes mellitus and hypertension, and one with thyrotoxicosis). Fourty-nine patients had a family history for other diseases: autoimmune diseases (psoriasis, AA, vitiligo), atopic manifestations, hypertension, and diabetes mellitus. Of the total patients, 44.1% of patients presented with nail changes; 36.84% had maturity onset and 59.25% had juvenile onset AA. Mahmoud and Kamal (1998) concluded that nail changes are common in AA, occurring even in mild cases with minimal hair loss, being more with longer duration and recurrence; children and adolescents are more prone to nail changes than adults; and diffuse fine pitting and longitudinal ridging are the commonest nail affection.

[Mahmoud SF, Kamal AM. Nail changes in minimal alopecia areata. Gulf J Dermatol. 1998; 5 (1): 36-39.]

Kuwait

A survey performed by Bastaki et al. (1992) between 1985 and 1989 reported the overall incidence of genodermatosis in Kuwait Maternity Hospital to be 0.26 per 1000 livebirths. More specifically, the incidence of alopecia totalis was 0.012 per 1000 livebirths in Kuwait during the over-mentioned period of five years.

Nanda et al. (1999) studied the spectrum and pattern of skin diseases of children in Kuwait in 10,000 consecutive new patients; 96% were children of Arab descent. 162 dermatoses were recorded as part of the study and alopecia areata was reported in 6.7% with notable female preponderance. In 2002, Nanda and colleagues conducted a prospective study that included 215 children (97% of Arab ancestry) with AA to determine their clinical and epidemiologic features. A ratio 2.5:1 was noted among girls to boys with an age of onset between 2 and 6 years of age. 51.6% of cases had a positive family history of AA and nail changes were seen in 26.5% of the children. Nanda et al. (2002a) indicated that the age of onset, a positive family history of AA, and associated atopic disorders may not have an influence on the extent and severity of the disease. In a separate study, Nanda et al. (2002b) screened 80 Kuwaiti children with AA, without clinical evidence of thyroid disease, were screened for the presence of thyroid abnormalities. They also tissue typed 50 unrelated children with AA for human leukocyte antigen (HLA) class I and class II antigens. Thyroid abnormalities were detected in 14 children (17.5%). Among these, 11 children (14%) had thyroid autoantibodies. Kuwaiti children with AA were observed to have a significant association with HLA B21 (OR 18.850, 95% CI 4.404-80.677), B40 (OR 6.767, 95% CI 1.818-25.181), and HLA B12 (OR 4.833, 95% CI 1.198-19.505) antigens. In 2008, Nanda described a patient with neurofibromatosis type 1 having an association with alopecia areata and autoimmune thyroiditis.

Alfadhli et al. (2008) investigated evidence for the association of eNOS gene polymorphism with alopecia areata (AA). Genomic DNA was extracted from 176 subjects, 87 Kuwaiti AA patients and 89 healthy controls. Genotype (4b/4b) was found to have a significant association with susceptibility to AA and had a frequency of 22% higher in AA patients than in healthy controls.

[Bastaki L, Al-Awadi A, Naguib KK. Incidence of genodermatosis among the neonates in Kuwait Maternity Hospital: 1985 to 1989 survey report, Kuwait Medical Genetics Centre, 1992, Kuwait.]

 

Qatar

El-Tonsy et al. (1998) undertook a study on a series of patients with AA and to explore and report the immunohistochemical features of the skin lesions, and occurrence of a number of circulating auto-antibodies in patients with alopecia areata. The study population consisted of 87 patients with AA and 20 controls. Of the 87 cases of AA, 71 patients (80.9%) showed alopecia on the scalp and 16 patients (19.1%) had lesions on the face.Twenty eight cases (32.2%) had an association with other diseases, including: diabetes mellitus, atopic dermatitis, bronchial asthma, vitiligo, urticaria, psoriases, lichen planus, and thyroid diseases. In addition, many had a family history of AA and/or the other diseases associated with it. The high incidence (43.7%) of family history of AA was thought to be related to a tendency to marry within a few families in the state of Qatar, and might give some credence to the possibility of AA occurring in families as an autosomal dominant trait. One or more circulating auto-antibodies were detected in 43 patients (49.4%). Eleven patients (12.6%) had two auto-antibodies and two patients (2.3%) had three auto-antibodies. Only two (10%) of the controls had one circulating auto-antibody. The percentages of the autoantibodies found in these patients as the following: antitesticular antibodies (38.4%), antinuclear antibodies (9.2%), antithyroid thyroglobulin and antithyroid microsomal antibodies (8%), anticardiolipin (6.9%), antiantismooth muscle antibodies (5.7%), and antiparietal cell antibodies (4.6%). T4, T8, B lymphocytes, Langerhan cells, macrophages, and histiocytes were increased in the perifollicular cellular infiltrations. There was also an increased expression of HLA-DR predominantly in the inflammatory cells. In the 74 biopsies taken, the only abnormality noticed in the epidermis was a mild degree of focal spongiosis in 30 (40%) of the biopsies. Degenerative changes were present in the dermal connective tissue around the hair papilla in 48 (65%). Mononuclear inflammatory cell infiltrates were present around capillaries and hair follicles in 52 (70%) consisting mostly of lymphocytes with a few macrophages and histiocytes. There was no chromosomal abnormality detected in the peripheral blood of 20 patients (15 males and 5 females) using G-banding technique, however, this technique by itself does not exclude the possibility of genetic abnormalities. A high serum zinc levels was found in a significant proportion among AA patients comparing to the controls, especially in males with a recurrent form of AA, indicating that an excessive intake of zinc may impair the immune response. El-Tonsy et al. (1998) concluded that the findings regarding the autoantibodies studied and the perifollicular cellular infiltrate support the view that immunological factors play a role in alopecia areata.

[El-Tonsy MH, Azadeh B, Kamal AM, El-Domyati MBM, Ibrahim FA. Auto antibodies and immunohistochemical studies in alopecia areata. Gulf J Dermatol. 1998; 5(1): 40-45.]

© CAGS 2024. All rights reserved.