Rapid therapeutic response in refractory lichen amyloidosis treated with upadacitinib: a case report.

Lichen amyloidosis (LA) is an intractable, chronic pruritic skin disorder characterized by amyloid deposition within the dermal papillae. It manifests as severely itchy, hyperpigmented papules and cobblestone plaques mainly distributed on the extremities. Conventional treatment modalities often yield partial or temporary therapeutic effects with unstable efficacy. This paper describes the case of a 60-year-old Chinese male patient presenting with a 3-year history of progressive, refractory lichen amyloidosis involving bilateral limbs. Over a 2-year period, the patient had failed multiple successive and combined treatment regimens, including oral antihistamines and potent topical glucocorticoids, while histopathological staining results confirmed primary localized cutaneous amyloidosis. After monotherapy with 15 mg oral upadacitinib once daily, the patient achieved rapid remission: pruritus was greatly relieved within 1 month, with the numerical rating score dropping from 8 to 1-2; this improvement was accompanied by obvious flattening of the papules, a decrease in lesion quantity, fading of pigmentation, and the disappearance of cobblestone skin lesions. No short-term adverse reactions were observed during medication. This case adds new clinical evidence supporting the therapeutic value of JAK1 inhibitors in the management of refractory inflammatory dermatoses, confirms the key involvement of IL-31-dependent JAK1 signaling in the pathogenesis of LA, and highlights upadacitinib as a promising rescue regimen for conventional treatment-resistant lichen amyloidosis, offering clinicians a clinical reference for employing JAK1-targeted therapy to disrupt the pathological itch-scratch cycle. Nonetheless, larger prospective cohort studies and randomized controlled trials are still required to validate the long-term efficacy, optimal dosage, and safety profile of upadacitinib in patients with lichen amyloidosis.