Clinical Response to Combined Light Therapy (Narrowband UVB Phototherapy and 1064-nm Q-Switched Nd:YAG Laser) in Refractory Lichen Amyloidosis: A Case Report

Abstract

Lichen amyloidosis is a chronic form of primary localised cutaneous amyloidosis that may be difficult to manage when pruritic and hyperkeratotic lesions persist despite conventional therapy. This case report describes the clinical response and short-term safety of sequential light therapy in a 69-year-old woman with a 10-year history of erythematous, pruritic papules on the lower extremities and repeated partial responses to previous treatments. Following a torpid evolution despite treatments by multiple physicians, symptoms exacerbated in April 2025, prompting a visit to the dermatology outpatient clinic. Physical examination revealed Fitzpatrick skin phototype IV and a bilateral, symmetrical dermatosis localized to the pretibial region. The lesions featured skin-colored, hyperkeratotic, pruritic papules coalescing into verrucous plaques, alongside evident truncal varicosities. Histopathological examination with hematoxylin and eosin (H&E) staining revealed epidermal hyperplasia, hyperkeratosis, and hypergranulosis. Congo red staining demonstrated amorphous eosinophilic material in the papillary dermis, compatible with lichen amyloidosis. Topical management was initiated using a high-potency corticosteroid, antihistamines, and vitamin D3 nutraceuticals, yielding partial improvement at two months. Consequently, narrowband UVB (NB-UVB, 311 nm) phototherapy was added twice weekly, with a 48-hour interval between sessions, for 15 weeks. Following a 24-hour rest period, four sessions of 1064-nm Q-switched Nd:YAG laser were administered at 21-day intervals. A nine-month clinical follow-up upon completion of the regimen revealed a persistent reduction in pruritus and significant clinical improvement. Lichen amyloidosis is an uncommon form of primary localized cutaneous amyloidosis characterized by a relapsing course and resistance to multiple therapies. In this refractory case, the combined approach using light therapies represented a safe therapeutic alternative with a favorable clinical response, demonstrating a satisfactory evolution throughout the follow-up period.