Familial implications of autoimmune disease: Recurrence risks of alopecia areata and associated conditions in first‐degree relatives

Alopecia areata (AA), a complex autoimmune hair loss condition, affects approximately 2.1% of the population. Individuals with AA have increased susceptibility to diseases such as atopy and autoimmune disorders, but little is known about first‐degree relatives' risk to develop AA and associated conditions. Genetic counseling for multifactorial conditions, including autoimmune disease is complex, but potentially valuable. Anecdotally we know patients with AA ask medical providers about recurrence risk for family members as well as question whether they and their relatives are at risk for other conditions. Data on AA recurrence risks and comorbid conditions among relatives of affected individuals comprise valuable information that may guide clinical management by genetic counselors. This study investigated the recurrence risk of AA and compared the prevalence of associated conditions among first‐degree relatives to the general population. The study also assessed the validity of self‐reported conditions for a subset of participants. Relatives of individuals with AA (N = 155), recruited from the National Alopecia Areata Foundation Registry, completed telephone surveys about their personal medical history for 70 medical conditions associated with AA. Medical records for 60 participants were compared to self‐reported responses. One‐sided proportional tests, in which it is assumed the disease prevalence in first‐degree relatives is higher than for those in the general population, yielded a 7.8% estimated risk of AA versus the general population prevalence of 2.1%. Furthermore, there are increased risks of 33 associated conditions, including atopy and other autoimmune conditions. Comparison of medical reports to self‐reported conditions indicated only 12% was incongruent. The findings may help genetic counselors better serve patients and their families by informing them of lifetime risk estimates of developing AA and comorbid conditions, resulting in early diagnosis of autoimmune diseases in AA families. Findings also provide evidence supporting the validity of self‐report data in AA families.