Panniculitis With Arthralgia in Patients With Melanoma Treated With Selective BRAF Inhibitors and Its Management

Background: Painful lobular panniculitis appears to be a novel cutaneous adverse effect of selective BRAF inhibitors. Observation: We report the clinical course and management in 2 women with metastatic melanomas harboring the BRAF(V600E) mutation, who developed panniculitis with arthralgia during therapy with selective oral BRAF inhibitors. Panniculitis with arthralgia was the acute presenting adverse effect in both patients. Painful, red, nodular lesions were located on the upper and lower extremities. Biopsy specimens of the nodules showed a mild, predominantly lobular neutrophilic panniculitis. Analgesic and anti-inflammatory treatment improved panniculitis and arthralgia in both cases. It was also necessary to reduce the BRAF inhibitor dose in 1 patient. Conclusions: During therapy with selective BRAF inhibitors, panniculitis with arthralgia represents a new adverse effect that can require dose reduction. In case of this adverse effect, treatment with nonsteroidal anti-inflammatory drugs, such as etoricoxib, should be initiated early to keep patients on treatment and to avoid drug discontinuation and tumor progression.