Serum Sickness in Patients Receiving Equine Rabies Immunoglobulin

Abstract

Background: Equine Rabies Immunoglobulin (ERIG) is being used for treatment of category-III animal bite cases. ERIG is economical as compared to Human Rabies Immunoglobulin (HRIG) and hence more affordable to patients in developing countries, like India. Despite high degree of purification, there are reported cases of serum sickness like reactions, anaphylaxis, and other allergic reactions following ERIG administration. Serum sickness is a type III or immune-complex-mediated hypersensitivity reaction that results from the injection of heterologous or foreign protein or serum. Because of fear of side effects (including serumsickness- like reaction) following ERIG, the use of ERIG is minimal among doctors. Objective: (1) To assess the incidence of serum sickness following the administration of ERIG. (2) To see the clinical features of serum sickness. Methods: This is a hospital-based cross-sectional study carried out in the ARV OPD of SCB Medical College, Cuttack, Odisha, India. All patients who received ERIG between September 2016 and December 2016 were included in the study. Side effects were monitored during the subsequent follow-up visits. Results: Out of 1548 category-III animal bite cases who received ERIG, 3.1% developed serum-sickness-like reactions, which manifested as rashes in 97.82%. Most of them had symptoms after seventh day following ERIG administration. Symptomatic relief with oral antihistamines like Cetirizine, Levocetirizine in 60% of cases and Inj. Avil (chlorpheniramine maleate) in 17% was achieved, and only one case required shortcourse corticosteroids. Conclusion: Despite 3.1% of serum sickness cases reported in our present study, the safety of ERIG has been proved and serum sickness can be managed with oral analgesics and antihistamines. Hence ERIG should be encouraged among doctors for use in category-III animal bite patients to prevent rabies.