Autonomic dysfunction and clinical severity of disease in children with allergic rhinitis

Abstract Objectives The involvement of autonomic imbalance has been reported in the pathogenesis of allergic diseases. Purpose To investigate the association between the clinical severity of childhood allergic rhinitis and autonomic nervous system (ANS) dysfunction, to define whether the severity of disease correlates with ANS activity. Methods In this cross-sectional, case–control study, we evaluated the ANS testing by measuring sympathetic skin response (SRR) and heart rate (R-R) interval variation (RRIV) in 55 children with perennial allergic rhinitis (PAR), aged 7–12 yrs without any chronic co-morbidity, and the results were compared with 40 sex- and age-matched control subjects. The patients were divided into two groups according to the severity of allergic rhinitis. Results There were significant increase in calculated RRIV variables during at rest and deep breathing in children with PAR compared to controls, which reflect parasympathetic nervous system (PNS) activity ( p < 0.005). The mean amplitude of SSR in patients, which reflect sympathetic nervous system (SNS) activity was smaller compared with the controls, but this difference was not significant (0.61 ± 0.35 μV vs controls 0.94 ± 0.46, p > 0.05). Lower RRIV and the prolonged SSR latencies in children with AR were closely correlated with disease severity ( r = −0.65, p < 0.05, and r = −0.59, p < 0.05 respectively). Conclusion Combined use of these two tests, allows separate testing of PNS and SNS function, and are very sensitive methods in assessing of severity of disease in children with PAR.