Clinical entity of Lupus erythematosus panniculitis/lupus erythematosus profundus

We reviewed the clinical and histological characteristics of the 44 cases of lupus erythematosus profundus (LEP) that have been encountered in our department. The female to male ratio was 4.5:1. The mean age of the females was 36 years, and the mean age of the males was 34 years. The most common sites were the face (38.4%) and upper limbs (26.0%). Even among the patients with LEP alone many of the positive patients had low antibody titers of 1:40 or 1:80. In 18 of the 44 cases SLE was complicated by LEP, and in those cases there was a tendency for LEP to develop during the course of SLE (11 cases). The important histological findings were lobular panniculitis associated with mucin deposition (32 cases) and a tendency to be associated with damage to the basal cell layer. In addition, the direct immunofluorescence test was positive in both the basement membrane (90.5%) and blood vessels (85.7%) in a high percentage of even the cases of LEP alone. Based on the above findings, LEP is a cutaneous variant of erythematosus, and the importance of the histological findings when making the diagnosis of LEP was reconfirmed.