The association of anxiety with granuloma annulare: a case-control study of the National Institutes of Health 'All of Us' research programme.

Dear Editor, Granuloma annulare (GA) is an inflammatory skin disease that has been associated with diabetes, dyslipidaemia, hypothyroidism and autoimmune disorders.1,2 The annualized incidence and prevalence of GA in the USA are approximately 0.04% and 0.06%, respectively (with a female predominance).3 GA is clinically classified as localized (75% of cases), generalized or subcutaneous.4 There is a body of evidence supporting an association between several inflammatory dermatoses, such as psoriasis, and mental health conditions.5 Improvement of depression and anxiety following treatment of certain inflammatory dermatoses has also been described.5 It has been postulated that this association may, in part, relate to proinflammatory cytokines, which have been proposed to mechanistically connect inflammatory dermatoses and mental health conditions.6 A recent nested case-control study demonstrated a significant association of GA with depression, insomnia, opioid dependence and post-traumatic stress disorder.7 This study aims to investigate whether an association exists between GA and anxiety.