Human T-Lymphotropic Virus 1 (HTLV-1)-Associated Lichenoid Dermatitis Induced by CD8+ T Cells in HTLV-1 Carrier, HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis and Adult T-Cell Leukemia/Lymphoma

The study reviewed 50 patients with HTLV-1-associated diseases from 2002 to 2012, focusing on those with skin lesions showing lichenoid tissue reactions predominantly infiltrated by CD8+ T cells. These patients included HTLV-1 carriers, those with HAM/TSP, and those with smoldering ATLL. The skin conditions observed were erythroderma, lichen planus, alopecia areata, chronic actinic dermatitis, and discoid lupus erythematosus. The researchers coined the term HTLV-1-associated lichenoid dermatitis (HALD) to describe these conditions, suggesting that HALD may be linked to elevated immunity against HTLV-1-infected CD4+ T cells, similar to the immune response seen in HAM/TSP.