Cutaneous lesions of the digits in systemic lupus erythematosus: 50 cases

The objective of this study was to observe the clinical and pathologic features of digital lesions in a cohort of 50 patients with systemic lupus erythematosus (SLE). Biopsy and pictures of digital lesions were performed in 50 consecutive patients with SLE and digital lesions. A clinical diagnosis of vasculitis was previously suggested in 36% of cases. Pictures were reviewed by three dermatologists and all the tissue sections were analysed by the same pathologist. Files of patients were reviewed retrospectively. Activity of SLE was established according to the lupus activity index (LAI). Digital lesions in SLE were frequently painful (60%) with a finger-pulp inflammation (70%). According to clinical and pathological correlation, five patients had acute cutaneous lupus, five subacute cutaneous lupus, 21 discoid lupus and 15 chilblain lupus. Two patients presented vasculitis: one had an urticarial vasculitis concomitantly to a lupus flare, the other had an erythema elevatum diutinum, independent of SLE evolution. Thrombosis of dermal vessels was present in two patients with SLE-associated antiphospholipid syndrome and in two patients with chilblain lupus. LAI was >1.5 in only seven patients. These results highlight the tendency to clinically overestimate the prevalence of cutaneous vasculitis of the fingers in patients without active SLE. Clinical features of cutaneous lupus of the digits are polymorphous. So, a pathological examination of the lesions is often necessary for diagnosis and proper management.