Reactions Weekly | 2021
Natalizumab
Abstract
Eosinophilic fasciitis: case report A 51-year-old man developed eosinophilic fasciitis during treatment with natalizumab for multiple sclerosis. The man, who had a history of ankylosing spondylitis and relapsing-remitting form of multiple sclerosis resistant to different therapies, presented with a 3-month history of progressive non-pitting oedema of the legs. His skin was found to be thickened and indurated. Also, he had limited joint mobility and myalgia. His ankylosing spondylitis was well controlled under the influence of prednisone treatment. To achieve better control on the relapsing-remitting form of multiple sclerosis, he was started on IV infusion of natalizumab 300mg every 4 weeks 3 months earlier. Following each infusion, he developed painful non-pitting oedema, which wss spontaneously regressed in 6/7 days, without any treatment. After the last infusion, the edema was found to be persistent. Therefore, he was hospitalised. Cardiac, hepatic and renal workup were noted to be normal. Both legs and feet revealed bilateral sclerosis with a peau d’orange appearance. On the pretibial region, a superficial indentation along the course of a superficial vein was noted, which was compatible with the groove sign . Based on these findings, a various differential diagnoses, including systemic sclerosis, nephrogenic systemic fibrosis, morphea profunda, and scleromyxedema were made. Laboratory investigations revealed a high WBC count with mild eosinophilia. However, CRP, erythrocyte sedimentation rate and blood sugar levels were within normal range. Hepatic and muscular enzymes were normal and antinuclear antibodies and extractable nuclear antigen antibodies were negative. Borrelia serology was negative. An ultrasound imaging ruled out the possibility of acute deep vein thrombosis. Cutaneous ultrasound imaging demonstrated increased signals in the fascia and dermal oedema. Abdominal ultrasound and chest X-ray were negative for neoplasms. Histopathological examination revealed orthokeratosis and dermal oedema, with a perivascular inflammatory infiltrate and rarely eosinophils. Also, hypodermal fibrous thickening of septa and eosinophilic infiltrates of fascia were noted. Based on the clinical and histopathological findings, a diagnosis of natalizumab-related eosinophilic fasciitis was made [duration of treatment to reaction onset not stated]. The man’s treatment with natalizumab was discontinued after discussion with the neurologist. The Naranjo Adverse Drug Reaction Probability Scale showed score of 8, which indicate probable relationship. He was treated with methylprednisolone along with a three months cycle of UVA 1-phototherapy and physiotherapy. A rapid improvement was noted in the sclerotic lesions.