Early detection of epidermal dust-like particles in experimentally UV-induced lesions in patients with photosensitivity and lupus erythematosus.

Dust-like particles, producing a specific fine-speckled, epidermo-subepidermal direct immunofluorescence staining pattern, have been associated mainly with subacute cutaneous lupus erythematosus (LE). Under experimental conditions the appearance of immunoglobulins along the basement membrane in ultraviolet (UV) light-induced lesions has been reported as a late phenomenon. In this study, photoprovocations with UVA and UVB light were carried out in 16 photosensitive patients with discoid (n = 13), subacute cutaneous (n = 2) or systemic LE (n = 1) and serial biopsies from UV-induced lesions were processed for direct immunofluorescence. A specific, fine-speckled epidermal staining was detected within 7 to 14 days after UV provocation in 7/16 of the patients; in the majority of those patients associated with anti-SSA antibodies adn discoid LE without systemic manifestations of their disease.