Cutaneous Lupus — “The Pimple That Never Went Away”
A 28-year-old woman presented with an erythematous rash involving the nose, nasolabial folds, and philtrum that appeared after she had manipulated a painful vesicular lesion at the base of her nose that she believed to be a pimple. The patient received cloxacillin for presumed erysipelas and had a partial response. However, after cloxacillin therapy, worsening induration (Panel A) prompted treatment with intravenous antibiotics, which had no effect. The patient reported recent sun exposure before noticing the extent of the symptoms. Subsequent laboratory tests were positive for antinuclear antibodies, anti-Ro antibodies (antibody index, 2.7 [normal, <1.0]), and anti-La antibodies (antibody index, >8.0 [normal, <1.0]) and showed a C3 level of 1.13 g per liter (normal, 0.79 to 1.52) and a C4 level of 0.17 g per liter (normal, 0.16 to 0.38). A punch biopsy specimen of skin from the right cheek showed vacuolar interface dermatitis and perivascular and perifollicular lymphocytic infiltration of the dermis — features that are consistent with discoid lupus erythematosus, a type of cutaneous lupus erythematosus. Cutaneous lupus erythematosus is often provoked by exposure to sunlight; the rash typically extends from the cheeks over the bridge of the nose and spares the nasolabial folds. This patient received treatment with oral prednisone and hydroxychloroquine, and the rash became less prominent, with only residual skin pigmentation (Panel B).