Posttussive emesis as a symptom of asthma in children

Background

Emesis can be triggered by cough in children, and cough is a common symptom of asthma.

Objective

To explore the association between posttussive emesis and asthma in the pediatric population.

Methods

A questionnaire was distributed to parents of children between the ages of 2 and 17 years in the pediatric and allergy-immunology clinics at our institution from August 16 through November 3, 2008. Prevalence of posttussive emesis was determined and compared among children with physician-diagnosed asthma, children with no evidence of asthma, and those not formally diagnosed as having asthma but with surrogate markers suggestive of asthma. The predictive value of posttussive emesis was compared with those of known markers of asthma. The prevalence of gastroesophageal reflux and pertussis was evaluated because these conditions might also cause posttussive emesis.

Results

The prevalence of posttussive emesis was 33% in our study population of 500 children. Among those with physician-diagnosed asthma (n = 122), 56% reported a history of posttussive emesis. For patients not formally diagnosed as having asthma but with surrogate markers suggestive of asthma (n = 62), 71% had a history of posttussive emesis. Both of these were significantly higher than in those with no evidence of asthma (n = 316), in whom 16% reported a history of posttussive emesis (P < .0005). Children with posttussive emesis were significantly more likely to have asthma than those without posttussive emesis (odds ratio, 7.9; 95% confidence interval, 5.2–12). Neither pertussis nor gastroesophageal reflux accounted for the degree of posttussive emesis reported.

Conclusions

Posttussive emesis is more common among children with asthma than among nonasthmatic children. In children with cough and a history of posttussive emesis, asthma should be strongly considered in the differential diagnosis.

Introduction

Cough is one of the most common presenting symptoms for children in the outpatient setting and is a frequent cause of consultation with a pediatric subspecialist.1, 2 Determining the cause of the cough is often a challenge for physicians but is essential for guiding the management of these patients.

The diagnosis of asthma can be elusive, particularly in young children who may have suggestive symptoms but in whom objective data collection can be technically difficult.³ Even in older children, although pulmonary function testing can provide objective evidence of asthma, results may be normal in an asymptomatic child with mild asthma.⁴ Biomarkers, such as exhaled nitric oxide, might be helpful in quantifying inflammation, but its role in routine practice is still being defined.5, 6 Ultimately the evidence to support a diagnosis of asthma relies on obtaining a thorough history, and any historical clues that can help distinguish the asthmatic child from the nonasthmatic child will likely improve the management of these children.

Posttussive emesis has historically been associated with Bordetella pertussis infections, in which violent coughing paroxysms are often followed by emesis.⁷ Most of the medical literature on posttussive emesis refers to this association with pertussis. An exception is a case series reported by Schreier et al8, 9 in 1987, in which patients had vomiting as the primary presenting symptom of asthma. These cases are presented as rare exceptions, with the intent of encouraging physicians to broaden the differential diagnosis of the vomiting patient. We hypothesized that posttussive emesis is actually common in children and is more common among those with asthma, thus making it a useful historical clue to help differentiate the origin of a child's cough.