Palmoplantar Lichen Planus-Like Lupus Erythematosus Keratoderma: An Underrecognized And Distinctive Cutaneous Manifestation Of Systemic Or Subacute Lupus Erythematosus

Palmoplantar keratoderma (PPK) is a rare cutaneous manifestation associated with systemic lupus erythematosus (SLE) considered as non-specific and distinct from palmoplantar discoid LE (DLE), chilblain LE or lichen planus (LP)-LE overlap syndrome. Herein, we report an underrecognized clinicopathological entity of LP-like/LE PPK associated with SLE or subacute LE subset. Twelve patients (11 females/1 male; median age: 56.5 years [20-78]) with PPK associated with SLE according to the 2019 European League Against Rheumatism and American College of Rheumatology classification criteria were evaluated in six French Departments of Dermatology, Rheumatology and Internal Medicine over 18 months. PPK occurrence was inaugural of the SLE diagnosis in one-third of the cases after a median delay of 4.5 years (0-40).