Reappraisal of Ikeda's classification of alopecia areata: analysis of 356 cases from Chandigarh, India

Defining Severity in Alopecia Areata: Current Perspectives and a Multidimensional Framework

Alopecia areata (AA) is an autoimmune disease characterized by nonscarring hair loss. As a clinically heterogeneous disease, various classification systems have evolved for defining its severity. In this high-level review of the literature, we discuss the traditional classification systems for AA severity and their strengths and weaknesses. Most recent classifications have focused on the extent of scalp hair loss as a defining feature, but additional clinical aspects of the disease, including location, pattern, and duration of hair loss as well as impact on the patient's quality of life, are also relevant. These various components have typically been used unidimensionally to classify patients. We propose a multidimensional framework to define AA severity that incorporates multiple patient- and illness-related domains. Using such a framework, dermatologists may better assess the severity of the disease for the individual patient beyond the extent of hair loss.

Clinical characteristics and prognostic factors in early-onset alopecia totalis and alopecia universalis

Alopecia totalis (AT) and alopecia universalis (AU), severe forms of alopecia areata (AA), show distinguishable clinical characteristics from those of patch AA. In this study, we investigated the clinical characteristics of AT/AU according to the onset age. Based on the onset age around adolescence (< or ≥ 13 yr), 108 patients were classified in an early-onset group and the other 179 patients in a late-onset group. We found that more patients in the early-onset group had a family history of AA, nail dystrophy, and history of atopic dermatitis than those in the late-onset group. These clinical differences were more prominent in patients with AU than in those with AT. In addition, significantly more patients with concomitant medical disorders, especially allergic diseases were found in the early-onset group (45.8%) than in the late-onset group (31.2%). All treatment modalities failed to show any association with the present hair condition of patients. In the early-onset group, patients with AU or a family history of AA showed worse prognosis, whereas this trend was not observed in the late-onset group. Systemic evaluations might be needed in early-onset patients due to the higher incidence of comorbid diseases. It is suggested that patients with AU or family history of AA make worse progress in the early-onset group than in the late-onset group.

Alopecia areata: Clinical presentation, diagnosis, and unusual cases

Alopecia areata (AA) is a nonscarring hair loss disorder with a 2% lifetime risk. Most patients are below 30 years old. Clinical types include patchy AA, AA reticularis, diffuse AA, AA ophiasis, AA sisiapho, and perinevoid AA. Besides scalp and body hair, the eyebrows, eyelashes, and nails can be affected. The disorder may be circumscribed, total (scalp hair loss), and universal (loss of all hairs). Atopy, autoimmune thyroid disease, and vitiligo are more commonly associated. The course of the disease is unpredictable. However, early, long-lasting, and severe cases have a less favorable prognosis. The clinical diagnosis is made by the aspect of hairless patches with a normal skin and preserved follicular ostia. Exclamations mark hairs and a positive pull test signal activity. Dermoscopy may reveal yellow dots. White hairs may be spared; initial regrowth may also be nonpigmented. The differential diagnosis includes trichotillomania, scarring alopecia, and other nonscarring hair loss disorders such as tinea capitis and syphilis.

Profile of 513 patients with alopecia areata: associations of disease subtypes with atopy, autoimmune disease and positive family history

BACKGROUND

Several lines of evidence support a genetic component to alopecia areata (AA), including differences in patients based on severity of AA, associated diseases and family history.

OBJECTIVE

We aimed to examine clinical and genetic features of patients with AA with a focus on associated diseases, especially atopy, and family history of AA in the USA.

METHODS

From 1998 to 2001, 513 patients with AA completed interviews consisting of demographic information, patient's medical history, and family history of AA.

RESULTS

Forty per cent of respondents had alopecia totalis and/or universalis (AT/AU). These patients were younger at the age of onset than those with patchy AA (P < 0.001), were more likely to have associated autoimmune or atopic disease (P = 0.047), most notably atopic dermatitis (P = 0.021) and thyroid disease (P = 0.012). They also had a greater number of relatives affected by AA (P < 0.05).

CONCLUSIONS

Our findings show marked associations between severity of AA, atopic dermatitis, thyroid disease and other autoimmune diseases, and extensive family history of AA, suggesting two clinically distinct subtypes of AA with the severe subtype possibly associated with greater familial autoimmunity. Further research exploring the possibility of a genetic basis to explain these clinical findings will be helpful in clarifying our understanding of AA, leading to improvements in diagnosis and treatment.

Epidemiology and genetics of alopecia areata

The frequency of alopecia areata and observed patterns of heritability are in keeping with a polygenic inheritance model but the genetics of alopecia areata is still poorly understood. The role of environmental factors in triggering disease initiation or exacerbation remains almost entirely speculative. Using the candidate gene approach, three susceptibility/severity factors have been identified. HLA alleles were the first to show a strong association with alopecia areata and some DQB and DR alleles have been demonstrated to confer a high risk for disease by both case-control and family-based studies. Interleukin (IL)-1 cluster genes, mainly the IL-1 receptor antagonist, show a strong association with disease severity in alopecia areata and a number of other autoimmune and inflammatory diseases. Finally, the association of alopecia areata with Down's syndrome, the high frequency of alopecia areata in autoimmune polyglandular syndrome type I due to mutations of the autoimmune regulator (AIRE) gene on chromosome 21q22.3 and the finding of association with MX1, another gene in the Down's syndrome region of chromosome 21 indicate this area of the genome as a promising target for future-family based investigations. The role of individual genes of the MHC, IL-1 cluster or chromosome 21q22.3 is difficult to establish and further genetic and functional investigations are needed to confirm their involvement in the pathogenesis of alopecia areata.

Alopecia areata: an autoimmune disease?

A wide range of hypotheses such as focal infection, trophoneuroses, and endocrine dysfunction, have been previously proposed to explain the pathogenesis of alopecia areata (AA). Currently, the most widely held belief is that AA is an autoimmune disease with cellular and/or humoral immunity directed against anagen hair follicle antigen(s). However, until recently evidence in support of an autoimmune mechanism of AA has been largely circumstantial. More fundamental evidence has recently been amassed in support of AA as an autoimmune disease by using animal models. These data include: 1) identification of cross-species hair follicle specific IgG autoantibodies, 2) The ability to induce AA in an animal model with transfer of skin from affected to naive individuals, and 3) the induction of disease by transfer of lymphocytes to human skin grafted to severe combined immunodeficiency mutant mice. A review of the previous and current data related to the autoimmune basis of AA is provided to put into perspective the future studies needed to definitively determine whether AA is an autoimmune disease.