Scarring alopecia in discoid lupus erythematosus: a clinical, histopathologic and immunopathologic study

Scarring alopecia is a very frequent feature of chronic discoid lupus erythematosus (DLE). So far in the literature, only clinic-pathologic features or histopathologic-immunopathologic traits of DLE scarring alopecia (DLESA) have been reported. We describe the most significant features of clinical morphology, histopathology, serum and tissue immunopathology of 36 DLESA patients (41.9% of all our scarring alopecia patients). Clinically, 33.3% presented a single lesion and 52.7% presented multiple lesions of scarring alopecia, while 13.8% exhibited a picture resembling Pseudopelade of Brocq, with the classic 'footprints in the snow' appearance. The most frequent morphologic features were sclero-atrophy (80.5%) and erythema (63.8%). The main histopathologic aspects appeared to be fibrosis (100%), follicular hyperkeratosis (91.4%), epidermal atrophy (88.5%), lymphocytic infiltrate (88.5%), thickened basement membrane (77.1%) and basal vacuolar degeneration (74.2%). Antinuclear antibodies were present in 42.8% of patients and antigastric mucosa, antithyroid and anticardiolipin antibodies in 17-21% of patients. A positive lupus band test was demonstrated in 81.8% of cases and perivascular deposit in 30.3% of patients. Histopathology alone allowed a correct diagnosis only in 68.5% of cases; in the other cases, the diagnosis was assessed also taking into account immunopathologic findings. Our study defines the clinic, histopathologic and immunopathologic features of DLESA patients and points out that a multiparametric approach is mandatory to assess the diagnosis of DLESA.