Severe subtype of alopecia areata is highly associated with thyroid autoimmunity

OBJECTIVES: 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. METHODS: 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. RESULTS: 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<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<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). CONCLUSION: 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.