“When I went to the emergency room with my terrible case of hives, the emergency room doctor told me I must be allergic to something. Please tell me which food is causing my hives so I can stop eating it. What medicines can you give me to treat the itching that doesn’t make me so sleepy like Benadryl?”
We frequently see cases like this in our daily practice. This patient was very frustrated with having chronic hives, or chronic idiopathic/spontaneous urticaria for 3 months. We took an extensive history, asking about new medications that she may have started taking prior to the urticaria starting. We also asked about any insect sting that may have caused the hives to come out. Nothing in her history suggested any potential cause of the hives. During her visit we also did skin testing which showed she is not allergic to any foods. As I expected, she did not have any allergies: there was NO EXTERNAL cause to her urticaria or hives.
SO, WHAT IS CAUSING HER HIVES?
It’s important to know that there has been multiple studies reported in the literature regarding causes of urticaria presenting to an emergency room. The results are consistent. About one third of the time there is no allergic cause for the urticaria. It seems hard to believe, but it is true. The other two thirds of urticaria or hives caused by an allergy are a combination of food, insect stings, and medications (e.g. antibiotics or aspirin/Motrin type products).
We know that most ALLERGIC causes of hives result in the hives coming out within a few minutes to an hour of the exposure. For example, if someone is allergic to shrimp, they will break out within an hour (typically within minutes) of eating shrimp. One important exception is aspirin and ibuprofen type medications. These may cause hives that occur hours after taking the medication.
The bottom line is: NOT ALL HIVES ARE A SIGN OF ALLERGY TO AN EXTERNAL FACTOR such as a food.
Incidentally, many researchers are starting to refer to chronic idiopathic urticaria as chronic “spontaneous” urticaria. I agree with trying to change the terminology. “Spontaneous,” I think, is a better descriptive word of the problem (idiopathic is a medical term that means we don’t know what is causing the problem). In fact, we do know that chronic idiopathic/spontaneous urticaria is mainly caused by unstable histamine cells that reside in the skin. These unstable cells spontaneously burst open and release chemicals such as histamine that cause the hives and the severe itching.
HOW DO WE TREAT THIS TERRIBLE PROBLEM?
We usually are quite successful treating this problem with non-sedating antihistamines such as Claritin or Allegra, but using higher than the recommended dosages (under medical supervision, of course). Typically this works very well and doesn’t make the patient sleepy. Sometimes we have to add other medications such as H2 blockers (acid reflux medications that have antihistamine properties) and other anti-allergic type medications. When this is not successful, we will use a drug called Omalizumab. This is an injectable drug which is quite effective in controlling hives. In any case, the vast majority of our patients do very well in the treatment of the urticaria, with very little side effects of the medications. And the good news is that almost every patient will get a break from their urticaria after a few months. That is, most urticaria is not truly chronic – some people can go years between bouts of urticaria.
For more information, contact Asthma and Allergy Associates of Florida at 561-368-2915.
Dr. Neil Gershman MD
Food allergies are growing food safety and public health concern. They affect 4%–6% of children and up to 4 % of adults in the United States. Food allergy symptoms are most common in babies and children, but they can appear at any age. Though less common; one can develop an allergy to foods eaten for years without a problem.
Why do food allergies happen?
The body’s immune system keeps one healthy by fighting off infections and other dangers to good health. A food allergy reaction occurs when the immune system overreacts to a food or a substance in a food, identifying it as a danger and triggering a protective response.
Which foods can be involved?
While any food can cause an adverse reaction, eight types of food account for about 90 % of the reactions; Milk, Eggs, Wheat, Soy, Peanuts, Tree nuts, Fish and Shellfish.
What are the symptoms of food allergies?
Symptoms of food allergy can range from mild to severe. They can present with one or more of the following: vomiting, abdominal pain, hives, tongue or throat swelling causing hoarseness or difficulty talking, inability to breathe, repetitive cough, wheezing, dizziness or feeling faint, weak pulse. Anaphylaxis is the most severe presentation of food allergy in which 2 or more of the above described symptoms happen together. This can be life threatening and has to be treated immediately. One should call 911 in case of having a life threatening reaction.
A food allergy will usually cause some sort of reaction every time the trigger food is eaten. The symptoms may be the same or different every time. The symptoms might even worsen with each exposure.
What is the timing of the reaction in relation to food?
Most food-related symptoms occur within two hours of ingestion; often they start within minutes.
Is there other kind of reaction related to food allergy?
There are some delayed reactions in the form of worsening eczema in some individuals. There are also some gastrointestinal conditions involving delayed allergies to foods; namely Eosinophilic Esophagitis. There is also a delayed food allergic condition called FPIES (food protein induced enterocolitis syndrome) which is usually seen in babies. It involves severe vomiting and diarrhea which can lead to dehydration and shock.
What is the amount of food which can trigger a reaction?
The amount of food needed to trigger an allergic reaction is different for everyone. Some people react to just a tiny exposure of food and some react after ingest a larger amount.
How is food allergy diagnosed?
You should talk about your symptoms with your primary doctor and discuss about seeing a specialist who deals with allergies. An allergist is a specialist doctor who is trained to diagnose and manage food allergies.
To make a diagnosis, the allergist will ask detailed questions about your medical history and your symptoms. They will also order skin testing and/or blood tests to arrive at a diagnosis. Skin testing involves pricking the skin with an allergen extract and a control and monitoring the area for a wheal/flare reaction (looks like a mosquito bite) . The test is not painful but the skin can be itchy where the extract is placed. A positive test does not always mean an allergy but a negative test is helpful in ruling it out. The blood tests are less accurate than the skin tests. Your allergist might use one or both types of tests to diagnose food allergies.
How is food allergy treated?
The primary way to manage a food allergy is to avoid consuming the food that triggers the allergy. There is currently no cure for food allergies; nor are there medicines to prevent reactions.
Read food labels to ensure that you don’t eat foods that contain ingredients which you are allergic to. Many ingredients have alternative names which can be confusing. Always ask about ingredients when eating at restaurants or when you are eating foods prepared by family or friends.
In case you have severe food allergy; carry an epinephrine auto injector which is prescribed by your doctor. It is a lifesaving medication which is injected into the thigh muscle in case you are having anaphylaxis. Antihistamines like Benadryl can also be used in case of mild symptoms. Talk to your allergist about having an anaphylaxis action plan and discuss treatment approach for mild symptoms.
It is especially important for children with severe food allergies in day care and school to have well documented list of food to be avoided and have an epinephrine auto injector available at all times. School personnel should know how to handle emergency situations.
What is difference between food allergy and food intolerance?
Many people who think they are allergic to a food may actually be intolerant to it. Some of the symptoms of food intolerance and food allergy are similar, but the differences between the two are very important. Proper diagnosis and distinction between food allergies and intolerance is important which can be done by an allergist.
Can I outgrow my food allergies?
It is possible for children with food allergies to grow out of them; this is especially true for foods like milk, eggs, wheat and soy. Peanut and tree nut allergies tend to be more persistent. Allergies which develop later in life tend to be lifelong. Your allergist can help in figuring this out.
I am allerigic to peanuts, is my child allergic to it?
Not necessarily, though immediate family members may be at an increased risk for food allergies. Your allergist can do simple tests to figure this out.
Where can get more information?
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