Generalized Actinic Granuloma After Prolonged Heat Exposure Improving With Baricitinib: A Case Report and Review of the Literature.

A 54-year-old Asian male cook had 12-month annular erythematous plaques on post-auricular regions, hand dorsa and forehead (central atrophy, mild pruritus, 0.5-8 cm), induced by prolonged heat exposure. T-spot, ANA, fungal test, and diabetes history were normal. Histopathology and reflectance confocal microscopy confirmed actinic granuloma (AG). Given AG's JAK1/2-STATs-related pathogenesis, baricitinib (2 mg/day) achieved marked improvement in 6 months, with no recurrence or adverse effects during 12-month follow-up.