Severe subtype of alopecia areata is highly associated with thyroid autoimmunity

To assess the significance of thyroid autoimmune screening in alopecia areata (AA) patients in Saudi population, and to determine whether there is a difference in thyroid autoimmune susceptibility between mild and severe AA.

In a prospective case-control study, we included 50 alopecia totalis (AT) and alopecia universalis (AU) patients, 50 age- and gender-matched patients with localized AA, and 50 age- and gender- matched healthy subjects between March 2015 and August 2015. Patients with AA were consecutively recruited from the hair disorders out-patient clinic of King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia.

Thyroid autoantibodies (TAAs) were positive in AT/AU (40%), mild AA (14%), and healthy subjects (4%). The frequency of TAAs was significantly higher in patients with AT/AU than in mild AA (p=0.001) and healthy controls (p less than 0.001). The frequency of thyroid peroxidase antibody (TPO-Abs) was significantly higher in patients with AT/AU than in mild AA and healthy controls (p less than 0.001 for both). The frequency of TG-Abs was significantly higher in patients with AT/AU (p=0.003) and mild AA (p=0.043) than in healthy controls. Serum TSH level was significantly higher in AT/AU patients than in mild AA patients (p=0.006) and healthy controls (p=0.005).

Severe subtype of AA is associated with a high risk of autoimmune thyroid disease. This highlights the significance of screening for thyroid abnormalities and TAAs in patients with AT/AU.