Rapid Desensitization to Reslizumab in an 80-Year-Old Woman With Chronic Eosinophilic Pneumonia, Severe Persistent Asthma, and Chronic Urticaria.

Our patient is an 80-year-old woman with chronic eosinophilic pneumonia (CEP), chronic urticaria (CU), severe persistent asthma (SPA), long-term oral corticosteroid therapy, and a resected papillary thyroid carcinoma. The patient had normal, stable immunoglobulin E (IgE) levels across all treatments ranging from 16 to 37 IU/mL. In treating her CEP and severe asthma, she trialed monoclonal antibody therapy with mepolizumab, benralizumab, dupilumab, and omalizumab, which were each begun and then discontinued successively due to severe side effects or allergic reaction. However, reslizumab offered 10 months of notable relief from urticaria and dyspnea without oral corticosteroids but was discontinued after the patient developed infusion-associated urticaria. Given her relief with reslizumab, we planned to desensitize her to this medication via a stepwise, slowed infusion up to a target therapeutic dose. Complete vital signs and physical exam looking for symptoms of an allergic response, including angioedema, urticaria, dyspnea, and nausea, were performed every 15 minutes. Our patient was successfully desensitized to reslizumab at a target dose of 195 mg over three hours. Vitals were checked every 15 minutes, which were within normal limits throughout. Further, she was monitored for any symptoms of allergic reaction, including angioedema, nausea, urticaria, and dyspnea, and denied any complaints throughout the procedure. Our patient reported notable relief of dyspnea and fatigue at two weeks and four weeks post-procedure. As opposed to a decrease in dose or discontinuation of treatment, patients may undergo rapid desensitization through a stepwise, slowed infusion rate to better tolerate a previously allergenic medication.