If your baby is showing signs of anaphylaxis, give epinephrine immediately if you have it and call 911. Every minute matters. Lay your baby flat (not upright) and keep them in that position until emergency help arrives. Anaphylaxis in infants can look different than in older children or adults, which makes fast recognition critical.
Recognizing Anaphylaxis in a Baby
Infants can’t tell you what they’re feeling, and many hallmark signs of anaphylaxis overlap with things babies do normally. Drooling, spitting up, loose stools, fussiness, and drowsiness can all be early signs of a severe allergic reaction, but they’re also things healthy babies do every day. That overlap is exactly what makes infant anaphylaxis dangerous: it’s easy to dismiss.
The signs that should raise immediate concern include:
- Skin changes: widespread hives, sudden flushing, or swelling of the face, eyelids, or lips
- Breathing trouble: wheezing, rapid or labored breathing, shortness of breath, or a blue tint around the lips or fingertips (cyanosis)
- Vomiting or diarrhea: sudden and repeated, especially right after eating a new food or being exposed to a known allergen
- Sudden limpness or drowsiness: becoming unusually floppy, unresponsive, or lethargic
- Scratching or clawing: at the face, mouth, or ears, which may signal itching or tingling the baby can’t describe
Anaphylaxis typically involves more than one body system at the same time. A baby who suddenly breaks out in hives while also vomiting or becoming limp is showing a pattern that should be treated as anaphylaxis until proven otherwise. Infants are more likely than older children to present with hives, wheezing, and vomiting as their primary symptoms.
Step-by-Step Emergency Response
If you suspect your baby is in anaphylaxis, act in this order:
1. Give Epinephrine
If you have an epinephrine auto-injector, use it right away. Do not wait to see if symptoms improve on their own. Epinephrine is the only drug that can reverse anaphylaxis, and delaying it increases the risk of a fatal outcome. Inject it into the outer mid-thigh. You can give it through clothing if needed.
For babies, dosing depends on weight. Auto-injectors come in two standard doses: 0.15 mg and 0.3 mg. The 0.15 mg dose is generally prescribed for children weighing between 10 and 25 kg (roughly 22 to 55 pounds). For babies under 10 kg (about 22 pounds), there is no commercially available auto-injector with a lower dose. The Canadian Society of Allergy and Clinical Immunology recommends that babies under 15 kg still receive the 0.15 mg auto-injector if they have a history of anaphylaxis, because the consequences of untreated anaphylaxis are far worse than the generally mild side effects of a slightly higher epinephrine dose.
2. Call 911
Call emergency services immediately, whether or not you’ve given epinephrine. Your baby needs to be monitored in an emergency department. Anaphylaxis can return hours after the initial reaction (called a biphasic reaction), so even if symptoms seem to improve, hospital observation is essential.
3. Lay Your Baby Flat
Hold your baby flat, not upright. This is one of the most important and least intuitive steps. During anaphylaxis, blood pressure drops rapidly, and standing or being held upright makes that worse by reducing blood flow to the heart. Laying your baby flat helps stabilize blood pressure. If your baby is having trouble breathing, you can let them sit with legs outstretched, but do not hold them upright against your shoulder. If your baby loses consciousness, place them on their side in a recovery position.
Keep your baby in this position even after giving epinephrine, even if they seem to recover. Do not pick them up to walk around or move them unnecessarily until paramedics arrive.
4. Be Ready to Give a Second Dose
If symptoms don’t improve within 5 to 15 minutes, a second dose of epinephrine may be needed. This is one reason allergists often prescribe two auto-injectors.
Common Triggers in Babies
About 90% of food allergies in children are caused by nine major allergens: milk, eggs, peanuts, tree nuts, fish, shellfish, wheat, soy, and sesame. For infants specifically, cow’s milk, eggs, and peanuts are the most frequent culprits. Peanuts and tree nuts tend to cause the most severe reactions.
First exposures aren’t always obvious. In one documented case, a 4-month-old with a confirmed cow’s milk allergy went into anaphylaxis after being given goat’s milk for the first time, because the proteins in goat’s milk are similar enough to trigger the same immune response. In another case, a 2-month-old developed anaphylaxis after a menthol-containing cologne was applied to their face, presenting with facial swelling, lip edema, and difficulty breathing. Triggers aren’t limited to food.
What Happens After the ER Visit
Once your baby is stable and discharged, the hospital team should prescribe an epinephrine auto-injector for you to carry at all times and teach you exactly how to use it. Most cases of infant anaphylaxis, including repeat episodes, happen at home, so being prepared outside the hospital is critical.
You’ll be told to strictly avoid whatever triggered the reaction until your baby sees an allergist. That follow-up appointment is important. Allergy testing (usually skin prick testing or blood work) helps confirm which allergen caused the reaction. If initial testing comes back negative but doctors still strongly suspect anaphylaxis, the testing may be repeated four to six weeks later. It can take that long for the immune system to “reset” enough for skin tests to show a positive result.
Long-term follow-up with an allergist serves several purposes: confirming or ruling out specific triggers, checking whether your baby has outgrown an allergy as they get older, identifying any new allergens, and adjusting the epinephrine auto-injector dose as your baby gains weight.
Building a Preparedness Plan
If your baby has been diagnosed with a severe allergy, work with your allergist to create a written allergy action plan. This document should include a clear list of your baby’s allergens, the specific symptoms to watch for, and step-by-step instructions for responding to anaphylaxis. It should also list all medications your baby takes, including dosage information.
Keep an epinephrine auto-injector with your baby at all times. Give copies of the action plan to every caregiver: grandparents, daycare providers, babysitters. Make sure each person has physically practiced with a trainer device so they won’t hesitate in an emergency. Epinephrine auto-injectors should be stored at room temperature (not in a hot car or refrigerator) and replaced before they expire. Carry two auto-injectors whenever possible, in case a second dose is needed or the first one malfunctions.