Systemic Janus kinase inhibitors in the management of granuloma annulare

Granuloma Annulare (GA) is an inflammatory granulomatous disorder that is typically localized to the skin. First line therapies for localized GA include topical and intralesional corticosteroids. Systemic corticosteroids have been used for generalized; however, rates of partial and complete resolution are disappointing. Recent advances in understanding the pathophysiology of macrophage activation and granuloma formation have led to Janus Kinase (JAK) inhibition as a therapeutic target for GA. The objectives of our study were to provide insight into the pathophysiology of GA and describe the clinical course and findings in patients with GA on JAK inhibitor therapy. This is a retrospective case series of 9 adults (age ≥ 18 years) with a diagnosis of GA and concomitant use of an oral JAK inhibitor. All patients on oral JAK inhibitor therapy (upadacitinib or abrocitinib) had improvement and/or clearance of their GA lesions within the first three months of therapy. Few adverse events commonly implicated in JAK inhibitor therapy (e.g., URI symptoms, malaise, acne) were reported. This study is limited by small sample size. JAK inhibitor therapy can be used in patients with GA, especially if they failed other treatments. Furthermore, JAK inhibitor therapy resulted in faster clearance time compared to other conventional treatments (e.g., antimicrobials, antimalarials, apremilast, methotrexate, and anti-tumor necrosis factor inhibitors). Depending on extent of GA involvement and patient-provider preferences, oral JAK inhibition therapy can be used off-label. Generally, these medications are well tolerated with few side effects compared to other GA treatment options.