Pertussis symptoms in adolescents and children versus infants: the influence of vaccination and age.

This study compared the influence of age and immunization status on symptoms in pediatric patients with pertussis. The files of 60 children, aged 7 to 18 years and 20 infants aged up to 6 months, admitted to our pediatric hospital with a diagnosis of pertussis were reviewed. There were no between-group differences in day and night cough or vomiting. The older group had a longer mean interval to diagnosis than the infants, and the infant group had more symptoms of whooping cough, facial redness during cough, cyanosis, a higher white blood count, a higher percentage of lymphocytes, and more abnormal chest X-rays. Statistically significant differences were found between vaccinated and unvaccinated older children for whooping cough and white blood cell count. Daytime and nighttime coughs are common symptoms of pertussis in all pediatric age groups, regardless of vaccination status. High white blood count is related to immunization status, and percentage of lymphocytes is related to age. In infants, symptoms are more grave but are typical, leading to early diagnosis.