Food Allergies in Babies

Of all the problems triggering persistent crying, baby food allergies and sensitivity rank right at the top. Diet-related colic and food allergy symptoms in babies account for about 90% of colic caused by a medical issue (For most babies, colic is non-medical and can be helped with the 5 S's.)

Looking for Signs of Diet-Related Colic and Food Allergies in Babies

Signs of Baby Food Allergies

Babies suffering from allergies usually fuss throughout the day (not just at night) and have loose stools, sometimes with streaks of bloody mucus. Unfortunately, no simple blood test has been found to diagnose these problems. Figuring out if your child has a food sensitivity requires you to play Sherlock Holmes and carefully collect clues.

Other Common Signs of Food Allergies in Babies

These are some common signs of food allergies (but please speak with your healthcare provider who will be able to help you sort through these possible symptoms to diagnose a food allergy or other issue):

  • Rash
  • Flushed skin
  • Hives or welts
  • Face, tongue, or lip swelling
  • Diarrhea
  • Vomiting
  • Difficulty breathing
  • Coughing or wheezing
  • Loss of consciousness

Common Food Allergies

If you think your baby has a food allergy, most likely the culprit will be one of these most common foods linked with food allergies:

  • Eggs
  • Cow’s milk
  • Tree nuts (think: almonds, walnuts, cashews)
  • Peanuts
  • Fish
  • Shellfish 
  • Wheat (gluten)
  • Soy

How to Test Your Baby for Food Allergies

If you’re breastfeeding, your doctor may recommend that you go a week without consuming cow’s milk, eggs, peanuts, tree nuts, wheat, soy and fish to see if the crying improves. If you’re bottle feeding, she may suggest you try a special hydrolyzed formula containing milk proteins that are “pre-digested” into tiny, non-allergenic fragments. In past decades, we used to recommend switching to soy or lactose-free milk or even a formula based on lamb protein, but there’s no evidence that any of these are truly effective for colic.

Using a Food Challenge to Suss Out Baby Food Allergies

If you do decide to try dietary changes, keep a daily journal for a week to keep track of any improvement in crying. Any reduction in fussing may be proof of an allergy, but it may also be coincidence. Your baby’s doctor should suggest you do food challenge to really figure things out: After avoiding certain foods for a week, reintroduce a spoonful of the suspected food into your diet (if you are nursing) or feed your baby an ounce of the suspected formula. Try it once a day over four days; if there’s an allergy, your baby’s crying (and/or mucousy stools) will probably return within a day.

Note: always ask your doctor before altering your baby’s diet…or your own.

About Dr. Harvey Karp

Dr. Harvey Karp, one of America’s most trusted pediatricians, is the founder of Happiest Baby and the inventor of the groundbreaking SNOO Smart Sleeper. After years of treating patients in Los Angeles, Dr. Karp vaulted to global prominence with the release of the bestselling Happiest Baby on the Block and Happiest Toddler on the Block. His celebrated books and videos have since become standard pediatric practice, translated into more than 20 languages and have helped millions of parents. Dr. Karp’s landmark methods, including the 5 S’s for soothing babies, guide parents to understand and nurture their children and relieve stressful issues, like new-parent exhaustion, infant crying, and toddler tantrums.

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Disclaimer: The information on our site is NOT medical advice for any specific person or condition. It is only meant as general information. If you have any medical questions and concerns about your child or yourself, please contact your health provider.