Investigators from Taichung, Taiwan, conducted a nationwide population-based retrospective study of the association between febrile seizure (FS) and allergic rhinitis. During an average 6.7 years follow-up of 1304 children with FSs, the incidence of allergic rhinitis in the FS group was higher, and after 11 years, the allergic rhinitis incidence was 4% higher than controls (p < 0.0001). Risk of allergic rhinitis in the FS group is 1.21 times higher than in the control group, and the risk is even higher (18.9) in patients with more than 3 FS-related medical visits. Both disorders have similar cytokine profiles and viral infection association. 
COMMENTARY. Fever and height of the body temperature as a measure of the FS threshold have an essential role in the mechanism of the FS. The cause of fever is almost always viral, most frequently HHV-6 in the United States and influenza in Japan. Some viruses have neurotropic properties, leading to the theory of a transient encephalitic or encephalopathic process in some cases. Additional factors involved in the mechanism of the FS include a genetic susceptibility, age and maturation, and cytokine and immune response to infection . The association of allergic rhinitis and FS in the present study was significantly higher in children 0.5 to 2 yrs of age (the age of susceptibility to FS), of male sex, and with frequent FS-related clinic visits. Children with FS had a higher association with other atopic comorbidities, including asthma (8.08% vs 5.62%, p = 0.006) .
Allergies and immune reactions are proposed as factors in the etiology of FS . In 1953, Dees, reporting on EEG observations in so-called “allergic epilepsy,” emphasized the significance of occipital dysrhythmia in children with allergies complicated by convulsions . Allergic disorders may also increase the risk of ADHD , and the risk of ADHD is increased in children with FS . A significant association between proinflammatory cytokine, IL-1B, and both ADHD and FS may be a link in the mechanism of these disorders .