pediatrics
Gastroesophageal Reflux in Infants
Etiology of Reflux in Infants
 is similar to that of Gastroesophageal Reflux Disease (GERD) : The lower esophageal sphincter (LES) fails to prevent reflux of gastric contents into the esophagus. LES pressure may transiently decrease spontaneously (inappropriate relaxation), which is the most common cause of reflux, or after exposure to agents such as cigarette smoke orcaffeine(in beverages or breast milk). The baseline esophageal pressures is normally negative, whereas the baseline stomach pressure is positive. The pressure in the LES has to exceed that pressure gradient to prevent reflux. Factors that increase this gradient or decrease the pressure in the LES predispose to reflux. For example, the pressure gradient may increase in infants who are overfed (an excessive volume of food causes a higher gastric pressure) and in infants who have chronic lung disease (lower intrathoracic pressure increases the gradient across the LES) and may increase because of positioning (eg, sitting increases intra-abdominal and gastric pressure). include Food Allergy , most commonly cow's milk protein allergy. A less common cause is gastroparesis (delayed emptying of the stomach), in which food remains in the stomach for a longer period of time, maintaining a high gastric pressure that predisposes to reflux. Infrequently, an infant can have recurrent emesis that mimics GERD because of a metabolic disease (eg, Complications of GERD are due mainly to irritation caused by stomach acid and to caloric deficit caused by the frequent regurgitation of food. Stomach acid may irritate the esophagus, pharynx, larynx, and, if aspiration occurs, the airways. Esophageal irritation may decrease food intake as infants learn to avoid reflux by eating less. Significant esophageal irritation ( Eosinophilic Esophagitis ) may cause mild, chronic blood loss and lead to esophageal stricture and food refusal. Laryngeal and airway irritation may cause respiratory symptoms such as tachypnea, wheezing, or stridor. Aspiration may cause recurrent pneumonia. 