Sex- and age-related differences in rabies immunoglobulin hypersensitivity

We retrospectively reviewed 72132 patients who had received rabies immunoglobulin between 1987 and 2005 at the Queen Saovabha Memorial Institute, Bangkok. Purified equine rabies immunoglobulin (ERIG) was given to 42965 (59.56%) patients and human rabies immunoglobulin (HRIG) to 29167 (40.44%) patients. A total of 812 patients from both groups (1.13%) reported adverse reactions; among those who had received ERIG, 43.13% were male and 56.87% were female, and among those who had received HRIG, 34.62% were male and 65.38% were female. Females were at higher risk of exhibiting ERIG or HRIG hypersensitivity than males (P<0.01). None of the reactions was life-threatening. Serum sickness-like reactions to ERIG and HRIG were rare under the age of 10 years (0.05 and 0.01% among recipients in that age group).