The Use of Fractionated Exhaled Nitric Oxide in the Diagnosis and Assessment of Disease Activity of Eosinophilic Esophagitis (Pilot)

Inclusion Criteria: * Pediatric patient who will undergo esophagogastroduodenoscopy with biopsies at Children's Memorial Hermann Hospital, as part of the standard of care in the evaluation of EoE * Able to perform the single-breath exhalation for the hand-held analyzer, NIOX MINO (Aerocrine, Sweden) * Signed informed consent by a parent or legal guardian * Signed assent form by the child/adolescent subjects 7-18 years of age Exclusion Criteria: * Past medical history of asthma, allergic rhinitis, IBD, parasitic infection, hay fever and any exposure to smoking (including secondhand smoke) because these disorders are known to affect the FeNO levels * Active respiratory tract infections at the time of FeNO evaluation because this can affect the result of the FeNO as well * Asthma questionnaire and/or Spirometry test consistent with asthma