More infants develop gastroesophageal reflux disease than formula allergy. Some of the symptoms of GERD bear similarity to a formula allergy, others do not. If your baby exhibits symptoms common to both, his pediatrician can do tests that help pin down the cause of his symptoms. Between 2 to 3 percent of babies have a milk allergy, according to child development experts at the Kids Health website, while as many as 67 percent have symptoms of reflux at 4 months, the American Academy of Otolaryngology explains, with over half of those resolving spontaneously by 10 months.
Both GERD and formula allergies can lead to digestive upsets, but the causes and some of the symptoms differ. Gastrointestinal symptoms common to both include vomiting, choking or gagging and abdominal pain after feedings. GERD develops when the valve between the stomach and esophagus doesn't close tightly. Spitting up and vomiting occur because formula refluxes out of the stomach through the weak valve. A baby with GERD might also refuse food, because he associates food with pain. With a milk allergy, vomiting occurs because the body attempts to rid itself of the offender. Blood in the stool can occur as a symptom of either disorder.
Both GERD and milk allergy can affect the respiratory tract in similar ways, but for different reasons. A baby with GERD often aspirates small amounts of acid, which irritates the lungs, causing wheezing, coughing and difficulty breathing. Allergic reactions lead to swelling in the bronchial tubes, which can also cause wheezing as well as difficulty breathing, choking and shortness of breath. Both disorders can also cause hoarseness.
Symptoms Specific to Milk Allergy
Only an allergy causes swelling around the eyes, mouth or lips, or skin reactions such as rashes or hives. In severe allergy reactions, the circulatory system can collapse, which causes loss of consciousness. Your baby might turn blue, indicating air can't reach his airway. His pulse might feel very fast or weak. In severe cases, any allergic reaction can cause enough swelling to close the baby's airway, which leads to collapse and the risk of death without treatment. Severe allergy symptoms occur more frequently with peanuts and tree nuts than with milk allergy, according to Kids Health professionals.
Symptoms Specific to GERD
While heartburn is one of the most common symptoms of GERD, babies can't describe it; they act as if they have pain in the chest or stomach. A baby with GERD might spit up yellow- or green-tinged formula. Acid entering the esophagus causes burning esophageal pain that can cause your baby to arch his back, choke or gag. A baby with GERD might also experience frequent bouts of pneumonia from aspirating acid into his lungs. While vomiting can occur with both conditions, effortless vomiting is more suggestive of GERD, the American Academy of Otolaryngology reports.
Skin testing can determine whether your baby has a formula allergy. Diagnosing GERD involves more testing; your baby's doctor might order ultrasounds, lab tests or more invasive procedures such as an upper GI series or endoscopy to diagnose GERD.