BI40 Prevalence of Strongyloides seropositivity in patients with eczema requiring biologic therapy in a UK multisite trust

Abstract

Biologic therapies, including dupilumab, modulate T helper cell 2 immunity and have transformed treatment of severe atopic dermatitis. Inhibition of interleukin-4 and linterleukin-13 signalling may increase susceptibility to parasitic infections like Strongyloides, which can cause potentially fatal disseminated disease in immunocompromised patients. Given high regional rates of Strongyloides, we routinely screen all patients with eczema prior to biologic therapy. This study aimed to determine the prevalence of Strongyloides seropositivity in dupilumab-treated patients, to describe management and adherence to ivermectin therapy, and to identify any reactivation or disseminated infection. A retrospective case note review was conducted of patients receiving dupilumab across a multisite UK trust. Data collected included patient demographics, Strongyloides serology, symptoms, stool investigations, ivermectin regimens, adherence and occurrence of disseminated infection. Among 211 patients receiving dupilumab for eczema, 189 (89.6%) underwent serology testing. Positive or borderline results were identified in 27 patients (14.3%). The largest ethnic group among seropositive patients was Bangladeshi (38%). Most seropositive patients were asymptomatic; symptom status and stool investigations were inconsistently documented. Mean eosinophil counts (× 109 cells L−1), excluding patients without contemporaneous blood tests, were similar: positive (n = 15) 0.60 (range 0.10–2.00), borderline positive (n = 5) 0.44 (0.30–0.90) and negative (n = 135) 0.60 (0.00–5.40). In total, 21 patients received ivermectin, with regimens varying: 5 received a single dose, 14 received two doses and 2 received four doses. Treatment was well tolerated, with no documented side effects. No disseminated strongyloidiasis occurred in treated or untreated patients. Asymptomatic Strongyloides seropositivity is common (14.3%) among our population with eczema requiring dupilumab. Ivermectin regimens varied but were well tolerated, and no disseminated strongyloidiasis or reactivation were observed. There was no clear relationship identified between eosinophilia and serology status. These findings support the safety and potential value of routine serological screening and early treatment in at-risk populations prior to biologic initiation. Prospective evaluation of untested patients may further clarify the true background prevalence and long-term reactivation risk.