How to recognize an allergic reaction

An allergic reaction in a child can be quite frightening for any parent or caretaker. Children and parents often sense something is wrong early on in a reaction, and many parents feel scared and helpless. Pediatric Allergist Jay Lieberman, MD, explains how you can recognize if a child is experiencing an allergic reaction below.

While the vast majority of reactions are mild and self-resolve, allergic reactions can be life-threatening. Thus, prompt recognition and treatment of an allergic reaction is very important.

Allergic reactions unfortunately do not all look the same. While portrayed comically as severe swelling in Hollywood movies like Hitch and Pure Luck, a true allergic reaction may or may not be so obvious in children, especially children too young to express their symptoms.

What are some signs of an allergic reaction?
Whether the allergen is a food, insect venom, drug or other trigger, the reaction can involve many organ systems and therefore be quite varied. Symptoms can include the following (patients may have just one or several of these):

  • Mouth/throat: Itching in the mouth, swelling of the lips, a scratchy throat, a feeling of throat closing or tightness
  • Skin: Swelling of any body part (usually lips, around eyes and face), itching all over the body, flushing all over the body, hives (welts) either in one area or all over the body
  • Stomach: Belly pain/cramping, nausea/vomiting, diarrhea (rarely)
  • Lungs: Trouble breathing, coughing, wheezing, hoarseness
  • Circulation: A sense of impending doom, faintness, passing out, turning blue

How long does it take for an allergic reaction to occur?
If it is an allergic reaction, these symptoms will typically occur within minutes of being exposed to the allergen (eating an allergic food, getting stung or ingesting an allergic medication) and resolve within hours. This timing issue is key in deciding if these symptoms are likely due to an allergic reaction.

What does an allergic reaction look like in toddlers or infants?
In infants and toddlers too young to express themselves, where foods are the most common culprit of an allergic reaction, parents will often say their child will spit out the food and claw or scratch their mouth as a first sign. Clearly, this can mean the child simply does not like the taste or texture of the food, but can be a first warning sign of an allergic reaction that can at least put parents on the alert.
What does an allergic reaction look like for a child who can express himself?
If they can express themselves, they may say their mouth hurts or burns to describe the oral itching sensation they are feeling. They may not look ill, but parents may notice a few hives (welts) popping up on their face, neck, back, or elsewhere while eating. Unfortunately, there is no specific pattern the reaction will take, so sometimes, the fist sign may be trouble breathing.

How can you tell if it’s an allergic reaction?
Also of importance is how allergic is the suspected food or trigger. For example, if this happens when the child first tries a common allergic food such as peanut, other nuts, fish, or shellfish (shrimp, crab, lobster, etc.), then it is likely an allergic reaction. However, if these symptoms occur randomly with no clear trigger, or after eating a food that the child eats daily without a problem, then the symptoms are less likely an allergy.

How can you prevent or treat an allergic reaction?
If you have recognized these symptoms, or believe your child might have had allergic reactions, I would recommend seeing an allergist to attempt to identify the allergic trigger. While avoidance is the mainstay of treatment for food allergies, there are new therapies in the pipeline. Patients with any life-threatening allergy should always be prescribed auto-injectable epinephrine to allow prompt treatment of any severe allergic reaction. If the allergy is to venom, then an allergist can also discuss with you whether venom allergy shots are right for your child.

Finally, there are references/handouts available to the public online that help anyone identify a possible allergic reaction and how to promptly treat it:

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