CPC11 Immune checkpoint inhibitor-associated eosinophilic fasciitis: a case report

Abstract

Abstract A 67-year-old man presented with a 3-month history of skin tightness associated with shooting, burning pains and numbness on both his upper and lower limbs. The patient had a background of metastatic bladder cancer, treated with six cycles of gemcitabine and cisplatin therapy from September 2019 to January 2020. Following this, he also had radical radiotherapy to the bladder, and in August 2020, he started pembrolizumab therapy. Pembrolizumab was paused in February 2022 due to the development of immunotherapy-related myositis. On examination, the patient had visibly shiny and thickened skin bilaterally involving the upper and lower limbs. Symptoms significantly limited the patient’s mobility and daily activities. A skin biopsy showed marked reduction in elastin fibres and mild fibromuscular thickening around the blood vessels, suggestive of scleroderma. Following a joint rheumatology and dermatology multidisciplinary meeting, a diagnosis of eosinophilic fasciitis (EF) secondary to the checkpoint inhibitor pembrolizumab was made. This was further supported by lower limb magnetic resonance imaging, which demonstrated evidence of bilateral oedema of the soleus muscle tendinous junction. Eosinophilic fasciitis is characterized by inflammatory infiltration, thickening and fibrosis involving the fascia. Unlike scleroderma, patients, such as in our case, with EF do not have sclerodactyly, Raynaud phenomenon, telangiectasias or nailfold capillary changes. Clinical manifestations of EF involve sudden onset, and pain and erythema (usually bilaterally) of the affected extremities. Patients have also been known to develop joint contractures, morphoea-like lesions and inflammatory polyarthritis. The reported triggers and causative agents of EF include trauma, autoimmune disorders and drugs. Only 13 cases have been reported secondary to pembrolizumab therapy, and the median time of symptom onset is 12 months following the commencement of checkpoint inhibitor treatment. According to the literature, there may be an underlying diagnosis of a solid tumour, haematological disorder or autoimmune disease. High-dose prednisolone is the primary treatment of choice, followed by methotrexate. However, some patients have shown spontaneous recovery. Our patient has now started a treatment course of high-dose intravenous methylprednisolone and methotrexate. While the therapeutic outcome is too early to report, he has already noticed improvements in skin tightening of the lower limbs.