Does your baby have hives from a food allergy, or is the red rash caused by something else? Learn how to tell whether your baby has food allergy hives or another type of hive, plus how to manage allergy hives when they emerge.
What are hives? What do they look like?
Hives are also called wheals or urticaria. They are raised, usually rounded bumps that are very itchy. Often, they are red in color, and have a red flare around them.
On babies with darker skin, hives usually won’t be red, and probably won’t have flares around them. Instead, they will appear the same color as the baby’s skin. They will still be raised and itchy, though. (Sometimes, hives may still be a darker red, or a subtle red, when they appear on a person with brown or Black skin.)
Hives could appear anywhere on baby’s body, and they can sometimes change shape or spread. You might see them in one or two locations on the body, or spread all over the body.
Each individual hive could range in size from a few millimeters across to several inches across.
But most of the time, hives will appear in clusters. So, an area or batch of hives may be much larger.
What causes hives?
Most of the time, hives are a sign that baby’s body has come in contact with something they are allergic to. Hives are one way that the body responds when it has an allergic reaction.
Hives can be caused by allergies to:
- Food (food allergies are the most common cause of hives in children)
- An insect sting or bite
Sometimes, hives can also be caused by skin irritants that don’t involve an allergy, such as:
- Chemicals (including harsher soaps, lotions, and detergents)
- Viral infections
- Bacterial infections
- Extreme heat or cold
- Friction from an abrasive material on skin
But why do these allergens and irritants cause hives?
If baby comes in contact with something they’re allergic to, or that irritates their skin, their mast cells (tissue cells) and blood cells release a chemical called histamine as a way to fight against the allergen or irritant.
When the histamine gets released, baby’s blood vessels widen and become leaky. The blood vessels release fluids that cause inflammation under the skin. This release of fluids creates the raised hives on the skin.
In the case of a food allergy, baby’s body makes special IgE antibodies that detect and over-defend the body against the food proteins that they are allergic to. When baby eats a food that they are allergic to, these IgE antibodies tell the mast cells to release histamine, causing the hives to form.
How can you tell if baby has food allergy hives?
As we’ve covered above, hives could form in response to several allergens and irritants. Sometimes, you won’t be able to tell what causes hives. But if the hives are caused by a food allergy, you’ll usually be able to tell.
There are several signs that baby’s hives are caused by a food allergy:
Food allergy hives will usually appear seconds to minutes after baby eats a food that they are allergic to. They will almost always appear within two hours after baby eats that food.
Pay attention to what your baby eats throughout the day, and when. That way, if hives don’t appear immediately after mealtime, you’ll know whether the hives appeared within two hours of eating, and if so, what food might have triggered the reaction.
*** Just like food allergy hives, hives caused by other allergens or irritants appear seconds to hours after contact. For example, if your baby hasn’t eaten within two hours, but came in contact with your dog or cat, the hives could be caused by a pet allergy. Or, if baby is stung by an insect, and hives appear immediately, the insect sting is likely the cause.
If you believe that hives are caused by any allergy (particularly a food allergy, insect sting allergy, or medicine allergy), contact your doctor. Your doctor may give advice on how to keep baby safe from allergen exposure, or encourage you to see an allergist for allergy testing.
Often, food allergy hives are accompanied by other symptoms of a food allergy (which we’ve listed in the sections directly below).
If you see just one small patch of hives on the body with no other symptoms, and not soon after baby’s mealtime, this may be a minor reaction to pollen or a pet.
But if baby shows any other symptoms of a food allergy, seconds to hours after eating a food, their hives are probably caused by a food allergy.
Hives are the most common symptom of a food allergic reaction, especially in babies and children. They are often the first symptom to appear (but not always).
Remember, though, that symptoms of a food allergy reaction can vary, even across multiple reactions that the same person experiences. A baby could have any combination of the below symptoms during a food allergy reaction.
What are mild symptoms of a food allergy?
- Hives (raised, itchy bumps) concentrated in one area of the body
- Occasional vomiting
- Skin redness in one area
- Swelling of the eyes, lips, or face
- Itchy, watery eyes
- Some stomach pain
- Some nausea
- Mild coughing
- Worsening eczema, if baby already has eczema
What are severe symptoms of a food allergy?
- Hives (raised, itchy bumps) that spread to many areas of the body
- Swelling of the throat
- Tightness of the throat
- Swelling of the tongue
- Trouble swallowing
- Trouble breathing
- Shortness of breath
- Repeated, significant coughing
- Noisy breathing (wheezing)
- Pale appearance
- Trouble vocalizing
- Change in voice or cry
- Repeated vomiting
- Drop in blood pressure
- Rapid heartbeat
- Loss of consciousness
- Feeling floppy (only in infants and young children)
A Note On Anaphylaxis: When the symptoms of a food allergy reaction are severe and involve more than one organ system, this is known as anaphylaxis. Anaphylaxis can be life-threatening. Call 911, and give epinephrine (use an Epi-Pen) immediately, if your child shows signs of anaphylaxis.
Where do food allergy hives appear?
Food allergy hives could appear anywhere on the body. Some of the most common places they can appear include the face, arms, hands, legs, feet, stomach area, and back.
Someone can have food allergy hives concentrated in one area of the body, or spread throughout the body.
How long do food allergy hives last?
A food allergy rash usually lasts for several hours after food allergy reaction symptoms first appear. Sometimes, it can last for up to 24-48 hours.
What’s the difference between mild and severe allergy hives?
If food allergy hives are concentrated in one area, the allergic reaction is mild. But if the hives spread to several areas of the body, this is a sign of a severe allergic reaction.
The same goes for hives caused by any other allergy. Concentrated hives in one area are a sign of a mild allergic reaction. But widespread hives are a sign of a severe allergic reaction
The sections below describe how to treat any allergy hives, whether they’re caused by a food, insect sting, medicine, or other allergic reaction.
How To Manage Mild Allergy Hives
How to manage mild hives, concentrated in small clusters on one area of the body?
First, if you believe that a food allergy caused the hives (or any other food allergy symptoms), immediately stop feeding your baby the food that you think triggered the reaction.
If a doctor has already recommended a specific dosage of antihistamine (Benadryl or Zyrtec), you can give your child the antihistamine to treat their mild hives. Antihistamine helps stop the release of the histamine that triggered the hives, but it’s only effective for stopping a mild or moderate allergic reaction (not a severe one).
If your doctor hasn’t recommended a dosage of antihistamine, call your pediatrician or allergist to alert them about the hives, and ask about next steps. Let them know what your baby ate, or what other possible allergens your baby came in contact with, within two hours of the reaction.
If you wish, you can apply hydrocortisone cream to the hives. Hydrocortisone cream may help to relieve the itchiness of hives, but it won’t make hives go away.
Most importantly, continue to monitor your child in case their mild allergic reaction turns severe. Any mild allergy reaction to food, an insect sting, or medicine could potentially get worse, and could even possibly develop into anaphylaxis.
How To Manage Severe Allergy Hives
If your child develops significant hives all over their body, but no other symptoms of an allergic reaction, call your doctor immediately. Stop feeding baby any food that potentially caused the reaction.
Continue to monitor your child for other symptoms of an allergic reaction, because if other severe symptoms emerge, your child will have anaphylaxis. If you have epinephrine (an Epi-Pen), give your child an injection. An antihistamine will not be able to stop this severe, widespread rash.
If your child develops hives all over their body, and it’s accompanied by severe symptoms in at least one other organ system, inject epinephrine (an Epi-Pen) immediately, and call 911. Your child is experiencing life-threatening anaphylaxis, and needs immediate emergency assistance.
Remember that epinephrine is the only medicine that can stop anaphylaxis. Antihistamines cannot stop this severe reaction.
Like food allergies, insect sting and medicine allergies can also potentially cause anaphylaxis. Inject epinephrine and call 911 any time your child experiences severe allergy symptoms in more than one organ system. Severe allergy symptoms may include trouble breathing, swelling of the throat or tongue, and cardiovascular symptoms.
Allergy Hives Vs. Other Skin Rashes
It’s also important to know the difference between hives and other rashes and bumps that appear on the skin. Here are other types of skin conditions that people sometimes confuse with allergy hives, and how to tell the difference.
Eczema (atopic dermatitis)
Eczema (atopic dermatitis) causes baby’s skin to become dry, rough, flaky, itchy, and sometimes red. When baby’s skin is exposed to certain irritants, their eczema will flare up (become worse). But baby eczema will never cause raised bumps (hives) to appear.
Baby acne looks very similar to acne that develops on teen and adult skin. It appears as hard red bumps (pimples), sometimes surrounded by small red inflamed areas of the skin. You may also see whiteheads on the bumps, just like with acne in teens and adults. Baby acne will last anywhere from a few days to a few months (much longer than food allergy hives last). It usually appears on the face, neck, back, or upper chest, and it’s never accompanied by any other symptoms.
Heat rashes suddenly appear on baby’s body when it’s hot outside. They look like baby acne, and usually appear on the areas of baby’s body that heat up most quickly: the face, armpits, wrists, and legs.They aren’t accompanied by any other symptoms.
Food Allergy Reactions In Babies Are Usually Mild
Recent research has shown that food allergies have never caused any deaths in babies under 1 year of age.
- Also, according to recent research led by Dr. Jonathan Spergel (Head of Allergy at Children’s Hospital of Philadelphia), only 3% of allergic reactions in infants resulted in cardiovascular or lower respiratory symptoms---significantly fewer severe reactions than in older children.
- And infants and toddlers had fewer reactions that required an Epi-pen, compared to older age groups.
- As children get older, though, food allergic reactions become more severe.
In addition, in 3 independent clinical trials involving early allergen introduction, with over 2,000 infant participants, there were zero severe reactions or hospitalizations.
So, it’s very safe to introduce allergenic foods to babies early and often --- food allergy reactions at this age tend to be mild. Baby’s first year is the safest time to start this introduction. In fact, several sets of recent clinical guidelines recommend introducing these foods prior to baby’s first birthday.
Our Chief Allergist and Board Certified Allergist Katie Marks-Cogan M.D, explains how early allergen introduction is inherently safe:
Ready. Set. Food! is an easy and safe way to start feeding your baby allergenic foods early. Most babies will not have an allergic reaction when introducing a new food, and the few reactions that do occur tend to be mild or moderate. This is consistent with research findings that show under age 1 is the safest time to introduce allergenic foods.
Hives, whether in one area or in multiple areas of the body, are a sign that your baby may be allergic to one of the allergens in Ready. Set. Food! If your baby appears to develop hives soon after eating Ready. Set. Food!, talk to your pediatrician or an allergist for guidance.
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