Rapid resolution of guttate psoriasis with upadacitinib: a case report.

We report a 30-year-old woman with acute, severe, and intensely pruritic Guttate Psoriasis (GP) who experienced a rapid and marked response to the oral selective JAK1 inhibitor upadacitinib. The patient presented with a 20-day history of rapidly spreading, intensely pruritic lesions after an upper respiratory infection, with a mildly elevated antistreptolysin O titer but no clinical or laboratory evidence of ongoing active infection. Notably, although she had previously responded well to secukinumab, an IL-17A inhibitor, the current flare occurred just 1 week after a scheduled injection. Conventional therapies, including antihistamines, topical steroids, and narrowband ultraviolet B phototherapy, failed to control either disease progression or the debilitating pruritus. Histopathological examination revealed epidermal hyperkeratosis with parakeratosis, acanthosis, elongation and downward extension of the rete ridges, dilated capillaries in the papillary dermis, and scattered lymphocytic infiltration, supporting the diagnosis of guttate psoriasis. After active infection had been excluded, upadacitinib 15 mg daily was initiated as an off-label rescue strategy. The patient reported significant pruritus relief within the first 24 h. After 2 weeks of treatment, near-complete clearance of skin lesions was achieved, and the patient completed a total of 28 days of upadacitinib therapy, resulting in complete resolution of the eruption. She subsequently underwent tonsillectomy, and no recurrence was observed during 6 months of follow-up. This case suggests that short course upadacitinib may represent a valuable therapeutic option for severely pruritic GP when rapid disease control is needed, but only after active infection has been excluded with careful safety monitoring.