Clinical Characteristics and HLA Alleles of a Family With Simultaneously Occurring Alopecia Areata

Although it was recommended that all 4 patients undergo psychiatric treatment and follow-up regularly with a psychiatrist, the patients declined. After approximately 1 year of dermatologic treatment, all 4 patients were lost to follow-up.

Comment

The etiopathogenesis of AA is unclear, but there is strong evidence suggesting that it is a T-cell–mediated autoimmune disease targeting the hair follicles. Common association of AA with autoimmune diseases such as vitiligo and thyroiditis support the immunological origin of the disease.³ In our case, patient 2 had AA along with vitiligo, but no associated autoimmune diseases (eg, vitiligo, diabetes mellitus, pernicious anemia, thyroid diseases) were noted in the other patients. Genetic and environmental factors are known to be influential as much as immune dysfunction in the etiology of AA.²

The presence of family history in 20% of patients supports the genetic predisposition of AA.⁴ In a genetic study by Martinez-Mir et al,⁵ susceptibility loci for AA were demonstrated on chromosomes 6, 10, 16, and 18. HLA antigen alleles, which provide predisposition to AA, have been investigated and associations with many different HLA antigens have been described for AA. In these studies, a relationship between AA and HLA class I antigens was not determined. Notable results mainly focused on HLA class II antigens.^6-8 Colombe et al⁷ and Marques Da Costa et al⁸ demonstrated that long-lasting alopecia totalis or alopecia universalis (AT/AU) patients had a strong relationship with HLA-DRB1^*1104; DRB1^*04/05 was reported to be the most frequent HLA group among all patients with AA.^6-10 In contrast, we did not detect these alleles in our patients. Colombe et al^7,11 noted that HLA-DQB1^*03 is a marker for both patch-type AA and AT/AU. Colombe et al¹⁰ showed that HLA-DQB1^*03 was present in more than 80% of patients (N=286) with long-lasting AA. Barahmani et al⁹ confirmed a strong association between HLA-DQB1^*0301, DRB1^*1104, and AT/AU. In our patients, we detected HLA-DQB1^*03/05 in patient 1 who had the earliest onset and most severe presentation of AA. In some studies, HLA-DRB1^*03 was found to be less frequent in patients with AA, and this allele was suggested to be a protective factor.^6,12 However, this allele was not detected in any of our patients.

The association of HLA alleles and AA has been investigated in Turkish patients with AA.^13-15 Akar et al¹³ and Kavak et al¹⁴ detected that the frequency of HLA-DQB1^*03 allele was remarkably higher in patients with AA than in healthy controls. These results were consistent with Colombe et al.¹⁰ On the other hand, Kavak et al¹⁴ reported that the frequency of HLA-DR16 was decreased in the patient group with AA. In another study, the frequency of HLA-B62 was increased in patients with AA compared to healthy controls.¹⁵ The HLA-DQB1^*03 allele was found to be associated with AA in only patient 1 in our case series, and HLA alleles were not commonly shared among the 4 patients. Additionally, lack of consanguinity between patients 2 and 3 (the parents) also suggested that genetic factors were not involved in our familial cases.

Blaumeiser et al¹⁶ reported a lifetime risk of 7.4% in parents and 7.1% in siblings of 206 AA patients; however, because these studies investigated the presence of AA in any given life period of the family members, their results do not reflect frequency of simultaneous AA presence within one family. In a literature search using PubMed, Google Scholar, and other national databases for the terms alopecia areata as well as family, sibling, concurrently, concomitant, co-existent, and simultaneously, only 2 cases involving a husband and wife and 1 case of 2 siblings who concurrently had AA have been previously reported.^17,18 Simultaneous presence of AA in more than 3 members of the same family is rare, and these cases have been observed in different generations and time periods.¹⁹ Among our patients, despite different age of onset and duration, AA was simultaneously present in the entire family.

Moreover, Rodriguez et al²⁰ reported that the concordance rate of AA in identical twins was 42% and dizygotic twins was 10%. Environmental factors and infections also have been implicated in the etiology of AA. Infections caused by viruses such as cytomegalovirus and Epstein-Barr virus have been thought to be potential triggering factors; however, no evidence has been found.^21,22 The clinical and laboratory examinations in our study did not reveal any presence and/or history of any known infectious disease, and there was no history of contact with water infected by acrylamide or a similar chemical.

Various life events and intense psychological stress may play an important role in triggering AA. Depression, hysteria, psychopathic deviance, psychasthenia, schizophrenia, anxiety, health concerns, bizarre thoughts, and family problems were found to be more frequent in patients with AA than healthy controls.²³ The most common psychological disorders associated with AA are generalized anxiety disorder, major depressive disorder, adjustment disorders, and phobias.^1,24 Ruiz-Doblado et al²⁵ determined the presence of psychiatric comorbidities in 66% (21/32) of AA cases. Chu et al²⁶ reported that the differences in ages of onset of AA revealed differences in psychiatric comorbidities. The risk for depression was higher in patients with AA younger than 20 years. An increased rate of anxiety was detected with patients with an onset of AA between the ages of 20 and 39 years. Obsessive-compulsive disorder and anxiety were more common in patients aged 40 to 59 years. Interestingly, the investigators also observed that approximately 50% of psychiatric disorders occurred prior to onset of AA.²⁶ One study showed higher rates of stressful life events in children than in controls.²⁷ Ghanizadeh²⁴ reported at least 1 psychiatric disorder in 78% (11/14) of children and adolescents with AA. In the same study, obsessive-compulsive disorder was found to be the second common condition following major depression in AA.²⁴