Food Allergy - Most Common Symptoms

At the core of every food allergy treatment plan are evasive maneuvers to steer you clear of the foods that commonly trigger reactions. In a world with so many foods and where certain ingredients pop up in the most unsuspecting places, avoidance can be nearly impossible 100 percent of the time.

Even my most careful and vigilant patients occasionally experience reactions, sometimes severe. For immediate relief and when avoidance is not 100 percent effective, the best available option is to treat the symptoms. Anaphylaxis is a sudden, severe, and potentially life-threatening allergic reaction.

You can minimize the severity of anaphylactic reactions by reacting to them in the following ways:

  • Recognize the symptoms early.
  • Self-treat immediately with the proper medications.
  • Seek emergency medical care promptly.

Effectively preventing future anaphylactic reactions hinges on avoiding the triggers. Whenever you experience a severe reaction, try to identify the specific trigger. Anaphylaxis is a frightening experience for the person who suffers the reaction, as well as for anyone in the near vicinity.

Dreading future reactions is normal, but you can take a few simple measures to reduce the risk and calm your fears. If you’ve experienced an anaphylactic reaction, visit an allergist for a workup. Your allergist can perform skin or blood tests to help identify your specific allergies, offer guidance on the treatment of future reactions, and provide you with a treatment plan in writing.

Avoidance is key to preventing future severe reactions. If you’ve experienced an anaphylactic reaction in the past, try to identify the food or foods that triggered the reaction, and strictly avoid those foods. See earlier article for details about avoidance diets and for food allergy sheets that can assist you in identifying allergens in processed foods.

If you have a severe or even potentially severe food allergies or have experienced an anaphylactic reaction, wear an allergy alert bracelet, necklace, or similar alert tag at all times. If you experience another reaction and are too ill to explain your condition, your tag can help responders provide proper treatment as quickly as possible. This measure is especially important in children.

The alert tag should include a list of known allergies, as well as the name and phone number of an emergency contact. One device, Medic Alert, provides a toll-free number that emergency medical workers can call to obtain your medical history, list of medications, family emergency contact numbers, and healthcare provider names and numbers.

Once you’ve experienced an allergic reaction, particularly a severe reaction, the last thing you want to think about is a future reaction that may be even worse, but that’s exactly what you need to do to save your life. Team up with your doctor to iron out the details and formulate your own plan using the form shown in Figure below.

This form can function as a great tool to include in your home emergency station. Because anaphylaxis can be life-threatening, you must treat it as you would treat any absolute medical emergency, including heart attack, stroke, or a severe diabetic reaction. An effective plan can save your life, minimize the severity of an anaphylactic reaction, and get you feeling a whole lot better a whole lot sooner.

Patients with a history of anaphylaxis or who are at risk of future anaphylactic reactions should always carry two epinephrine autoinjectors (EpiPen or Twinject). Epinephrine is the most effective drug. It treats all the symptoms of anaphylaxis, including the most threatening symptoms — low blood pressure, chest tightness or wheezing, and throat closure.

Your doctor can provide you with a prescription for epinephrine autoinjectors, but you also need to know some critical facts about autoinjectors to maximize their potential benefit:

  • Fill your epinephrine autoinjector prescription immediately.
  • Read the instructions provided with your autoinjector and review them with each refill just in case the instructions have changed.
  • Make sure you’re getting the right dose. Autoinjectors come in 2 doses — a junior for young children and a regular strength for everyone else. Officially, the full strength devices are approved for use for anyone over 66 pounds.

The junior strength is a perfect dose for someone who weighs 33 pounds, but for every pound above that it underdoses more and more. For this reason most experts, including me, recommend switching from junior to regular strength somewhere between 45 and 55 pounds.

  • Store epinephrine at normal room temperature away from cold and heat sources.
  • Examine the epinephrine cartridge window periodically to ensure that the solution is colorless and contains no floating particles. Replace solutions that are discolored or contain particles.
  • Check the expiration date on your autoinjectors regularly. (An expired autoinjector is better than no injector, so if all you can find during an emergency is an expired one, use it.)
  • Keep at least two epinephrine autoinjectors with you at all times. Having an additional autoinjector at work, school, and home is a great idea.
  • Store the home injector in a convenient location, and let family members and friends know where it is. Sticking it in the “junk drawer” or a cluttered medicine cabinet is a bad idea.
  • Get up to speed on how to use your injector, as explained later.
  • Train family members, close friends, teachers, and co-workers on proper use in preparation for a possible emergency. In the midst of a reaction, you may panic and be unable to assist with your own injection.
  • Act quickly when you first notice symptoms. A quick response is essential in preventing serious complications. Few, if any, known fatal reactions have been due to food-induced anaphylaxis when epinephrine was given promptly.
  • A second dose may be needed if symptoms are worsening or not improving within 10–15 minutes or if symptoms return before emergency personnel and equipment are available.

Both the EpiPen and the Twinject offer trainer devices for practice and to demonstrate proper use to others. Anyone who may need to use it must practice with the trainer first. Most people end up with lots of expired injectors and I find it helpful to shoot an orange or grapefruit with one of these to see what a real one feels like.

This is also a great practice tool for adolescents who are getting ready to take over responsibility for their medicines. If you have a history of severe reactions, grab you autoinjector and give yourself a shot as soon as you notice the telltale signs of a reaction. As a general rule, administer epinephrine immediately if you:

  • Have any two systems involved in a reaction, such as hives and stomach pains, or any other combination of two or more symptoms that affect different parts of your body
  • Are having trouble breathing
  • Feel tightness in your throat
  • Feel faint . . . as though you may pass out

Some people refuse to use epinephrine for fear of the needle. Others, including some doctors, won’t prescribe it because they fear the side effects. Epinephrine is a very safe medicine. For a huge majority of allergy sufferers, the benefit far outweighs the risks.

Discuss any concerns you have immediately with your doctor, and if your doctor is reluctant to prescribe epinephrine, you may need to do a little convincing or switch doctors. Although epinephrine is the first and best response to the onset of an anaphylactic reaction, other treatments are often used in addition to epinephrine to provide added relief:

  • Antihistamines: Diphendydramine (Benedryl) and other antihistamines, given by mouth or by injection, can help symptoms subside during anaphylaxis.
  • H2 blockers: Another class of antihistamines, called H2 blockers, may also be effective when added to the usual antihistamines — the H1 blockers. H2 blockers include medications like ranitidine (Zantac) and cimetidine (Tagamet), which are commonly used to treat ulcers and acid indigestion.
  • Inhalant medications: Albuterol and other asthma medications can help if you have difficulty breathing, chest tightness, or coughing.
  • Corticosteroids: Prednisone and other corticosteroids can help prevent a recurrence in the hours following an anaphylactic reaction and prevent late reactions, but they don’t work rapidly enough for emergency treatment.

Other treatment in the emergency room should address any life-threatening respiratory and cardiovascular symptoms. ER personnel may need to give you additional doses of epinephrine and possibly oxygen or a breathing tube (to keep your airway open) for severe breathing problems.

Treatment may also include medications to treat low blood pressure and cardiac arrhythmias (irregular heart beat). Even if symptoms are completely under control, your doctor should keep you under observation for a minimum of four hours due to the possibility of biphasic reactions.


Eczema is a condition that may or may not involve food allergy. As I discuss in earlier article, food allergy is responsible for about 40 percent of the cases, and even when food allergy is the prime suspect, it is almost never the sole suspect. I always tell my patients that some part of eczema is literally the skin you were born to have.

Even in the perfect environment and on the perfect diet, some people’s skin is just too dry, too itchy, or too sensitive. When food allergy is involved in eczema, the five most common food allergens are the most likely culprits: egg, milk, peanut, soy, and wheat. Other foods can certainly be involved but these top five are the most important to remember.

When food-allergy-induced eczema is itching to drive you crazy, avoiding the foods that trigger reactions is the first and most effective course of action, but symptoms can linger long after you stop consuming the food. If dryness and itchiness persist, treat the symptoms:

  • Moisturize, moisturize, moisturize. Use a cream rather than a lotion, and apply it at least once a day, particularly immediately following a bath or shower. Most people with eczema discover that taking a long bath in warm or tepid water provides much needed relief, but if you don’t follow up with moisturizer, that comforting bath can lead to drier and itchier skin later. If your eczema is severe, apply moisturizing cream multiple times per day.
  • Apply medicated creams. Medicated creams or ointments — usually steroid preparations such as hydrocortisone — can control skin inflammation. While some steroid creams are very potent and may be unsafe to use on a regular basis, especially in children, low-potency creams are very safe and can be used on regular basis, if needed.

Two nonsteroidal anti-inflammatory creams/ointments for treating eczema are presently on the market. Their safety, however, has recently come under scrutiny, and the FDA requires a black box warning on these products until further research ensures their safety.

  • Soothe the itch with oral antihistamines. Oral antihistamines can be valuable in relieving eczema’s severe itching. The older style antihistamines, including Benedryl, are particularly beneficial at bedtime, since their sedative side effect can help you sleep through the itch. For daytime itching, opt for a non-sedating antihistamine, such as Zyrtec, Clarinex, or Allegra.

Identify and avoid anything that further irritates your skin, including any clothing, soap, detergents, or lotions that exacerbate your eczema.


People who have hives know all too well what they are. If you itch inside and out, are covered with red splotches, and haven’t been camping in a cloud of mosquitoes, you probably have hives. What caused them? I discuss that topic and describe the telltale signs of a hives outbreak in earlier article, but if you have hives you probably don’t care where they came from.

All you want to know is how to shake them. The good thing about hives is that they typically go away much faster than a mosquito bite. They can be severe, but in most cases, a single dose of antihistamine leads to quick, long-lasting relief.

If someone comes to me complaining of a week or two struggle with hives, I rarely suspect that food allergy is playing a major role. To send your hives packing, I recommend the following medications, depending on the severity of the outbreak and the likelihood that the outbreak signals the beginning of a more severe reaction:

  • Old-style, fast-acting antihistamines like diphendydramine (Benedryl) are tried and true treatment for hives, although other antihistamines might be equally effective.
  • Liquid forms of antihistamines are great for treating food reactions, because your body tends to absorb them more quickly, but chewable or fast-melt tablets may be equally effective.
  • Epinephrine is the drug of choice if you believe that your hives are a sign of a potentially dangerous reaction. Consult your doctor.

Other conditions, including anxiety, can cause hives, so if your hives appear to be unrelated to the foods you eat, consult your doctor about other possible causes and their treatment. In earlier article I discusses the most common other causes.


Your gastrointestinal (GI) tract is like a pipeline, starting at your mouth and ending at your... well... you know. Gastrointestinal food reactions can occur anywhere along this pipeline, and symptoms vary depending on where the reaction hits. Reactions can be acute (occurring soon after exposure) or chronic, sometimes low-level reactions.

The GI tract is frequently involved in anaphylactic reactions. While a single episode of vomiting may not be cause for extreme concern, other GI symptoms, such as repeated vomiting or abdominal pain, are often a sign of a more severe reaction, so keep your epinephrine handy.

By definition, oral allergy syndrome is a reaction restricted to the lips and mouth and is characterized by itching (sometimes severe) and swelling (usually mild). Because the reaction is localized to the lips and mouth, it’s not dangerous in and of itself, but sometimes, oral allergy syndrome can foretell the onset of a more severe reaction, in which the term “oral allergy syndrome” no longer applies.

Another name for the oral allergy syndrome is the pollen related allergy syndrome. This name refers to the fact that the allergies that cause the syndrome — usually triggered by fresh fruits and vegetables — occur because of cross-reactivity with certain pollens.

People with allergy to tree pollens, for example, may experience oral symptoms after eating apples, cherries, or peaches, while those with ragweed allergy may react to melons or carrots. The allergies commonly associated with oral allergy syndrome are unique in the following ways:

  • These allergies begin to show up in later childhood, only after the pollen allergies are strong enough to trigger cross-reactivity to the related foods.
  • As opposed to most food allergens (peanut allergen becomes stronger with roasting), the allergens in these foods are largely destroyed by cooking. So someone with a reaction to fresh apples can usually eat apple pie or drink apple juice without experiencing a reaction. (Apple cider is another story.)
  • Symptoms may vary with the season. Some people know that their apple allergy will become more intense in the spring (tree pollen season) and then begin to wane by the summer or fall.
  • Allergy shots for the pollens associated with the allergenic food may make the related food allergy go away.
  • The skin of some fruits contains more allergen than the meat of the fruit.

Preventions and treatments for oral allergy syndrome vary, depending on the approach you decide to take:

  • Do nothing. Most people don’t even tell their doctors about the allergy and decide to live with it. If you enjoy the fruit or vegetable more than you dread having an itchy mouth and lips, then you may decide to partake of it.
  • Avoidance. If having an itchy mouth and lips isn’t worth the enjoyment, then you may choose to forego the food.
  • Strict avoidance. If eating these fruits or vegetables causes more severe reactions beyond those considered to be oral allergy syndrome, stricter avoidance is obviously needed.
  • Medicate. Most reactions, however, resolve on their own within 20 or 30 minutes with no treatment.

An eosinophil is a type of blood cell commonly found at the crime scene — the site of any allergic reaction. These cells are responsible for much of the inflammation that occurs in most chronic allergic conditions, including those that affect the skin (eczema), the nose (allergic rhinitis), the lungs (asthma), and the GI tract.

When eosinophils set course for your GI tract, they can cause a condition called allergic eosinophilic gastroenteritis — a chronic inflammation in the GI tract, sometimes localized and sometimes involving the entire GI tract. When the upper GI tract is involved, such as with eosinophilic esophagitis (swelling in the esophagus), symptoms include pain, reflux, poor appetite, and difficulty swallowing.

Swelling of the lower GI often results in pain, diarrhea, or weight loss. Food allergy causes most cases of eosinophilic gastroenteritis. In many cases, eosinophilic gastroenteritis is not an IgE-mediated allergy, meaning that the usual blood and skin tests may turn up negative for food allergy. Even so, your doctor may recommend a standard food allergy treatment:

  • Avoidance diet: Many of those who suffer from eosinophilic gastroenteritis have multiple food allergies, so a complicated avoidance diet may be needed.
  • Change in formula (for infants): In babies, sometimes a simple change of formulas may be sufficient for stemming future reactions.

When food avoidance is ineffective, steroids are the only medicines that clearly work. You may respond to a type of asthma medication called montelukast (Singulair) or other newer medications. Antihistamines are of little use. Other immunosuppressive agents may offer some relief, but they all carry risks and need to be monitored carefully, usually with the combined efforts of your allergist and gastroenterologist.

Eosinophilic esophagitis (EE) is a form of eosinophilic gastroenteritis that’s localized to the esophagus — your food chute. This condition is usually triggered by a food allergy, although environmental allergies can also contribute. In some cases, food allergy doesn’t even play a role.

When food allergy is the cause, avoidance is the key to feeling better. When the cause is something more than food allergy, I’ve had excellent success using steroid-based asthma inhalers. Instead of having patients inhale the medicine, however, I instruct my patients to spray it in the mouth and swallow it.

Allergic proctitis (or allergic colitis) is a pain in the . . . well . . . end of the intestinal tract. The condition is especially common in young babies with symptoms of blood and mucous in the stools. Milk or soy allergy is typically the cause, although other foods may be involved in breast-fed babies.

Because allergic proctitis is not IgE mediated, it generally responds well to one of the following treatment trials:

  • Formula fed: If the baby takes formula, then a milk-free or soy-free trial may clear up the condition.
  • Breast fed: If the baby is breast feeding, the mother may need to avoid soy, milk, and possibly other suspect foods on a trial basis to identify the problem food.

Allergic proctitis is a rather benign condition in which the babies tend to feel and grow well. Half the babies who have it are fine by the time they reach their first year, and most others can eat all foods by the age of two or three.

In young babies, a food allergy can cause a condition called enterocolitis syndrome, characterized by severe, repetitive vomiting that may lead to dehydration. Skin and blood tests are of no help in identifying food allergy, because the allergy is not IgE-mediated, but cause and effect usually provide a clear link to the food that’s triggering the reaction.

Milk and soy allergies are most common but these reactions also occur with a large number of other foods. Food avoidance is the only treatment, and most children outgrow the allergy by two to three years of age. During these latter years, your doctor may recommend re-introducing the problem foods, but you should proceed with extreme caution, because reactions can be severe.

Celiac Disease

Celiac disease, also known as gluten sensitive enteropathy, is a form of food sensitivity in which people can’t tolerate any form of gluten — a protein found in wheat, rye, and barley. Symptoms typically include abdominal pain, vomiting, diarrhea, and weight loss (or poor growth in young children).

Symptoms can be quite severe and appear very early in life or remain lowgrade, flying well below your doctor’s radar until adulthood. Although celiac disease is not IgE-mediated, your doctor can perform other blood tests to make an accurate diagnosis. In all cases strict avoidance of all gluten is essential and typically requires you to abstain from these foods for the rest of your life.


Short of breath? Coughing? Wheezing? If you are, you may have asthma, a chronic condition, and underlying allergies may be triggering the symptoms, but a food allergy isn’t the most likely cause. When you have an allergy-induced form of asthma, environmental allergens are the most likely suspects.

When you consult your family physician and describe your symptoms, she’s likely to offer a diagnosis based solely on your reported symptoms, or she may subject you to a series of breathing tests, assuming you’re at least five or six years old. Your allergist may perform a series of allergy tests, but these typically don’t include tests for food allergy, unless you report additional symptoms typical of food allergy.

Although food allergy typically plays only a minor role, if any, in asthma, if you have asthma and a food allergy, you’re at risk for experiencing more severe allergic reactions when you ingest a food that triggers a reaction, especially a reaction in which the throat and lungs are involved. Antihistamines have no effect on these reactions. In such cases, the reaction qualifies as an emergency.

Allergic Rhinitis

Most people attribute runny nose and sneezing to the common cold or hay fever. Something in your nose — a virus or irritant — must be causing the problem, right? Well, that’s usually true, but food allergies can also trigger symptoms in your snout, including a runny nose, sneezing, congestion, and itchy, watery eyes.

If an allergen is the cause, your sniffles and sneezes are probably due to a condition called allergic rhinitis. Rhinitis means nose — think rhinoceros. Whether your allergic rhinitis is triggered by environmental allergens or by a particular food, the symptom relievers are pretty much the same:

  • Antihistamines, including loratadine (Claritin) and diphendydramine (Benedryl).
  • Nasal sprays that often contain the same steroid medications used for asthma.
  • Leukotriene blockers, such as Singulair, can also be helpful in controlling nasal allergies.
  • A combination of nasal sprays and antihistamines (for the most stubborn cases).