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Lundgren, Linnea, and Jeff Wald. "Allergy Basics." 02 May 2006. HowStuffWorks.com. <http://health.howstuffworks.com/how-allergies-work.htm> 17 May 2008.
by Linnea Lundgren and Jeff Wald, MD
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Food Allergies
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Food Allergies
There are two types of reactions to food. One is the result of an actual allergy while the other is a result of an intolerance. Food intolerance is actually the more common of the two, but food allergies are the more serious. In this section, we will explore the symptoms and causes of food allergies as well as how to tell a food allergy from a food intolerance.What Is a Food Allergy?
A food allergy is a hypersensitivity or abnormal response by the immune system to a certain food.
It's a sensitivity that develops the same way as allergies to pollen or mold. First your body already needs to have encountered the allergen (in this case, a food) in order to have developed antibodies to it. That's why you can have eaten a peanut once and not have had a reaction to it. It's only the next time you eat a peanut that your body reacts as the antibodies to peanuts now rally themselves for a fight.
Food Allergy Symptoms
The symptoms of an allergic reaction to food range from tingling lips and tongue to abdominal cramps to difficulty breathing and, most seriously, shock. The site of the reaction and its severity can vary. When two or more organ systems are involved or if there is wheezing, the reaction is considered severe. Reactions may get progressively worse with subsequent exposures. Just because a person has had only mild reactions to an allergic food does not mean that the next reaction will not be serious and potentially fatal.
Food Allergies in Children
Like other kinds of allergies, the tendency to have food allergies -- but not the specific allergy -- is inherited. And certain foods, including milk, eggs, wheat, peanuts, fish, shellfish, and tree nuts, are the most frequent troublemakers. Children often have more food allergies than adults, especially to cow's milk and peanuts. Many food allergies in infants are outgrown by age four. Reactions to shellfish, fish, and tree nuts are more common in adults.
Which Foods Are Responsible for Your Allergies?
It can be tricky identifying what food is causing your symptoms. It's usually obvious, but it may not be, especially if you're reacting to a spice. Less obvious reactions require a bit of detective work.
The answers to the following questions can be revealing:
- What was the timing of the reaction?
- Does the reaction happen after eating a certain food or meal?
- Was the food fully cooked?
- What else was eaten (including spices, condiments, beverages...)?
- Did anyone else experience symptoms?
Even peanuts can be hard to avoid. As the saying goes, the world is full of nuts: Peanuts and peanut traces are found in cakes, cookies, candy bars, breakfast cereals, breads, Asian cooking (peanut oil is popular), ice creams, desserts, sauces and gravies, and a variety of processed foods. Therefore, people who have experienced or are at high risk for experiencing life-threatening food allergies are well advised to carry injectable epinephrine (which must prescribed by a doctor) and possibly antihistamines to reduce serious symptoms and buy time to seek medical help.
Food Intolerances
Food intolerance is a chemical reaction that doesn't involve the immune system. Classic examples include lactose intolerance, irritable bowel syndrome, and heartburn. Lactase deficiency ranks as one of the most common types of food intolerance. If your body doesn't have enough of the enzyme lactase, you can't properly digest lactose, the sugar found naturally in milk and milk products. Symptoms of lactose intolerance include bloating, abdominal cramps, and diarrhea.
Taste enhancers, fancy food colorings, and preservatives are also on the list of food intolerance causes. Perhaps the best-known example is monosodium glutamate (MSG), a flavor enhancer commonly used in restaurants and processed foods. When MSG is ingested in large amounts, sensitive individuals may experience flushing, headaches, and chest pain. Sulfites are another common cause of food intolerance. Sulfites are substances that occur naturally in some foods (such as wine) and are added in others to preserve texture and prevent mold. Asthmatics risk an attack if the sulfite-containing food they consume gives off sulfur dioxide. This gas irritates the lungs, causing spasms and constriction of the airways.
Now that we've covered food and skin allergies, it's time to look at other factors that can contribute to allergies. In the next section, we will explain how drugs and even your workplace can cause allergic reactions.
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Please copy/paste the following text to properly cite this How Stuff Works article:
Lundgren, Linnea, and Jeff Wald. "Allergy Basics." 02 May 2006. HowStuffWorks.com. <http://health.howstuffworks.com/how-allergies-work.htm> 17 May 2008.
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Heel Pain Hemolytic Crisis Hepatomegaly Heterochromia Hiccups Hip Pain Hoarseness Or Changing Voice Hump Behind The Shoulders Hyperactivity Hyperelastic Skin Hypermobile Joints Hyperventilation Hypotonia Impaired Smell Increased Head Circumference Indigestion Infantile Reflexes Intercostal Retractions Intertrigo Irritability Itching Jaundice (Yellow Skin) Joint Pain Joint Swelling Knee Pain Leg Pain Lichenified Limited Range Of Motion Lordosis Low Nasal Bridge Lower Back Pain Macule Malaise Memory Loss Metopic Ridge Microcephaly Micrognathia Morbid Obesity Morning Sickness Moro Reflex Motormental Retardation Mouth Sores Muscle Aches Muscle Atrophy Muscle Cramps Muscle Function Loss Muscle Twitching Nail Abnormalities Nasal Congestion Nasal Discharge Nasal Flaring Natal Teeth Nausea And Vomiting Neck Lumps Neck Pain Night Blindness Nightmares Nikolsky’s Sign Nipple Discharge Nodules Nosebleed Numbness And Tingling Obesity Opisthotonos Pain During Sexual Intercourse Painful Menstrual Periods Painful Urination Pale or Clay-Colored Stools Paleness Papule Patches Patchy Skin Color Pectus Carinatum Pectus Excavatum Penis Pain Photophobia Pilonidal Dimple Pinna Abnormalities And Low-set Ear... 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DISEASES AND CONDITIONS GLOSSARY:
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