Panniculitis — a group of conditions that causes painful bumps to appear under the skin — is a rare manifestation of childhood-onset systemic lupus erythematosus (cSLE) that occurs mainly in the first three years of disease, and seems to be an indicator of less severe systemic lupus, a study found.
The study, “Panniculitis in childhood-onset systemic lupus erythematosus: a multicentric cohort study,” was published in Advances in Rheumatology.
Systemic lupus erythematosus (SLE) is an autoimmune condition that affects multiple organs and systems, including the skin. Panniculitis, which consists of tender nodules caused by inflammation in the fat layer beneath the skin, appears in 2% to 5% of SLE patients.
However, while many SLE children and adolescents have symptoms in the skin and mucus membranes, little is known about the incidence and clinical manifestations of this rare form of cutaneous lupus erythematosus, called lupus erythematosus panniculitis (LEP).
To address this gap, researchers in Brazil examined 847 cSLE patients treated across 10 pediatric rheumatology services in Sao Paulo. Of them, six had LEP, confirmed through the presence of nodules and/or plaques in adipose tissues under the skin and through microscopic tissue examination.
In one patient, LEP occurred 2.6 years before lupus was diagnosed. In two other patients, the condition was observed at diagnosis, and the remaining three patients developed panniculitis several years — 5.5 years, 9.9 years, and 11.4 years — after their cSLE diagnosis.
All six patients had painful nodules, and four had painful plaques as well. Also, while one patient had LEP in the face only, and two in the upper limbs only, the remaining three had manifestations across the face, trunk, and limbs.
Treatments for LEP included prednisone, antimalarials, methotrexate, azathioprine, and cyclosporine. However, three patients failed to respond to these approaches and their symptoms improved only after receiving immunoglobulin, Rituxan (rituximab), or cyclophosphamide.
Researchers compared the six LEP patients with 60 patients chosen randomly from the remaining patient sample without LEP and with a similar disease duration. They found that more LEP patients had symptoms such as fever, fatigue, or weight loss, and low levels of white blood cells. However, disease activity and manifestations in kidneys or of a psychiatric nature were similar among the two groups.
“In our study children and adolescents with lupus panniculitis had a mild systemic disease, characterized by constitutional involvement and leukopenia,” researchers explained. “Indeed other studies observed that this cutaneous chronic manifestation might be an indicator of a less severe systemic lupus.”
Thus, researchers concluded that “panniculitis is a rare skin manifestation of cSLE occurring in the first three years of disease with a high frequency of sequelae,” adding that “the majority of patients presented concomitant mild lupus manifestations.”