Gastrointestinal Tract

A food allergy is an exaggerated immune response triggered by eggs, peanuts, milk, or some other specific food.

Allergy to food

Normally, your body's immune system defends against potentially harmful substances, such as bacteria, viruses, and toxins. In some people, an immune response is triggered by a substance that is generally harmless, such as a specific food.

The cause of food allergies is related to your body making a type of allergy-producing substance called immunoglobulin E (IgE) antibodies to a particular food.

Although many people have a food intolerance, food allergies are less common. In a true food allergy, the immune system produces antibodies and histamine in response to the specific food.

Any food can cause an allergic reaction, but a few foods are the main culprits. In children, the most common food allergies are to:

• Eggs
• Milk
• Peanuts
• Shellfish (shrimp, crab, lobster, snails, clams)
• Soy
• Tree nuts
• Wheat

A food allergy frequently starts in childhood, but it can begin at any age. Fortunately, many children will outgrow their allergy to milk, egg, wheat, and soy by the time they are 5 years old if they avoid the offending foods when they are young. Allergies to peanuts, tree nuts, and shellfish tend to be lifelong.

In older children and adults, the most common food allergies are:

• Fish
• Peanuts
• Shellfish
• Tree nuts

Food additives -- such as dyes, thickeners, and preservatives - may rarely cause an allergic or intolerance reaction.

An oral allergy syndrome may occur after eating certain fresh fruits and vegetables. The allergens in these foods are similar to certain pollens. Examples are melon/ragweed pollen and apple/tree pollen.

Many Americans believe they have food allergies, while in reality fewer than 1% have true allergies. Most people's symptoms are caused by intolerances to foods such as:

• Corn products
• Cow's milk and dairy products (See: Lactose intolerance)
• Wheat and other gluten-containing grains (See: Celiac disease)

Symptoms usually begin immediately, within 2 hours after eating. Rarely, the symptoms may begin hours after eating the offending food.

If you develop symptoms shortly after eating a specific food, you may have a food allergy. Key symptoms include hives, hoarse voice, and wheezing.

Other symptoms that may occur include:

• Abdominal pain
• Diarrhea
• Difficulty swallowing
• Itching of the mouth, throat, eyes, skin, or any area
• Lightheadedness or fainting
• Nasal congestion
• Nausea
• Runny nose
• Swelling (angioedema), especially of the eyelids, face, lips, and tongue
• Shortness of breath
• Stomach cramps
• Vomiting

Symptoms of oral allergy syndrome:

• Itchy lips, tongue, and throat
• Swollen lips (sometimes)

In severe reactions, you may have low blood pressure and blocked airways.

A blood or skin test can be done to identify elevated antibody levels (particularly IgE) and confirm that you have an allergy.

With elimination diets, you avoid the suspected food until your symptoms disappear. Then the foods are reintroduced to see if you develop an allergic reaction.

In provocation (challenge) testing, you are exposed to a suspected allergen under controlled circumstances. This may be done in the diet or by breathing in the suspected allergen. This type of test may provoke severe allergic reactions. Challenge testing should only be done by a doctor.

Never try to deliberately cause a reaction or reintroduce a food on your own. These tests should only be performed under the guidance of a health care provider -- especially if your first reaction was severe.

See: Allergy testing

The only proven treatment for a food allergy is to avoid the food. If you suspect you or your child has a food allergy, consult an allergy specialist.

If you have symptoms on only one area of the body (for example, a hive on the chin after eating the specific food), you may not need any treatment. The symptoms will likely go away in a brief time. Antihistamines may relieve the discomfort. Soothing skin creams may provide some relief.

Consult your doctor if you think you have had an allergic reaction to food, even if it is only a local reaction.

Anyone diagnosed with a food allergy should carry (and know how to use) injectable epinephrine at all times. If you develop any type of serious or whole-body reaction (even hives) after eating the offending food, inject the epinephrine. Then go to the nearest hospital or emergency facility, preferably by ambulance. Seek immediate medical attention after injecting epinephrine for a food reaction.

Food Allergy and Anaphylaxis Network -- www.foodallergy.org

Avoiding the offending foods may be easy if the food is uncommon or easily identified. However, you may need to severely restrict your diet, carefully read all package ingredients, and ask detailed questions when eating away from home.

Anaphylaxis is a severe, whole-body allergic reaction that is life threatening. Although people with oral allergy syndrome rarely have an anaphylactic reaction, they should ask their doctor whether they need to carry injectable epinephrine.

Food allergies can trigger or worsen asthma, eczema, or other disorders.

• Call your local emergency number, such as 911, if you have any serious or whole-body reactions (particularly wheezing or difficulty breathing) after eating a food.
• If your doctor prescribed epinephrine for severe reactions, inject it as soon as possible, even before calling 911. The sooner you inject the epinephrine, the better.
• Anyone who has had an allergic reaction to a food should be evaluated by an allergy specialist.

Breastfeedingmay help prevent allergies. Otherwise, there is no known way to prevent food allergies except to delay introducing allergy-causing foods to infants until their gastrointestinal tract has had a chance to mature. The timing for this varies from food to food and from baby to baby.

Once an allergy has developed, carefully avoiding the offending food usually prevents further problems.

Lack G. Clinical practice. Food allergy. N Engl J Med. 2008;359:1252-1260.

The "gooey stuff" is feces, often soft and in a small amount. The anus has a sphincter that holds it closed and should be "patent"--meaning, do the job it is supposed to do. There is always some bits of feces and fecal fluid present in the rectum. If the sphincter has been damaged, or if the expulsion of gas is forceful, it can force small bits of fecal matter through the anus.

These kind of expulsions are also called "wet farts" because it can feel like you messed yourself even when you did not.

Antifreeze is a liquid used to cool engines. It is also called engine coolant. This article discusses poisoning caused by swallowing antifreeze.

This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local emergency number (such as 911) or the National Poison Control Center at 1-800-222-1222.

See also:Ethylene glycol poisoning

Engine coolant poisoning

• Ethylene glycol
• Methanol
• Propylene glycol

• Various antifreezes

Note: This list may not be all inclusive.

• Airways and lungs
  • Rapid breathing
  • No breathing
• Bladder and kidneys
  • Blood in urine
  • No urine outputor decreased urine output
• Eyes, ears, nose, and throat
  • Blurred vision
  • Blindness
• Heart and blood
  • Change in body's acid-base balance, which can lead to organ failure
  • Rapid heartbeat
  • Low blood pressure
• Muscles and joints
  • Leg cramps
• Nervous system
  • Coma
  • Convulsions
  • Dizziness
  • Fatigue
  • Headache
  • Slurred speech
  • Stupor (lack of alertness)
  • Unconsciousness
  • Unsteady walk
  • Weakness
• Skin
  • Blue lips and fingernails
• Stomach and gastrointestinal tract
  • Nausea
  • Vomiting

Seek immediate medical help. Do NOT make a person throw up unless told to do so by poison control or a health care professional.

Use standard first aid and CPR for signs of shock or cardiac arrest. Call your local Poison Control Center or 911 for further assistance.

Determine the following information:

• Patient's age, weight, and condition
• Name of product (as well as the ingredients and strength, if known)
• Time it was swallowed
• Amount swallowed

The National Poison Control Center (1-800-222-1222) can be called from anywhere in the United States. This national hotline number will let you talk to experts in poisoning. They will give you further instructions.

This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.

Take the container with you to the hospital, if possible.

See: Poison control center - emergency number

The health care provider will measure and monitor the patient's vital signs, including temperature, pulse, breathing rate, and blood pressure. Blood and urine tests will be done.The patient may receive:

• Dialysis
• Fluids through a vein (IV)
• Medicines to treat symptoms
• Medicine (antidote) to reverse the effect of the poison
• Tube through the nose into the stomach to wash out stomach (gastric lavage)

For ethylene glycol: Death may occur within the first 24 hours. If patient survives, there may be little or no urine output for several weeks before the kidneys recover. Any brain damage may be permanent. Vision loss or blindness may also be permanent.

For methanol: Methanol is extremely toxic. As little as 2 TABLEspoons can kill a child, while 2 to 8 oz. can be deadly for an adult. The ultimate outcome depends on how much was swallowed and how soon appropriate care was given.

Berk WA, Henderson WV. Alcohols. In: Tintinalli JE, Kelen GD, Stapczynski JS, Ma OJ, Cline DM, eds. Emergency Medicine: A Comprehensive Study Guide. 6th ed. New York, NY: McGraw-Hill; 2004:chap 166.

A polyp biopsyis a diagnostic procedure that takes a sample of or removes polyps (abnormal growths) for examination.

Polyp biopsy

Polyps are outgrowths of tissue that may be attached by a stalk-like structure (a pedicle). They are commonly found in organs with many blood vessels, such as the uterus, colon, and nose. Some polyps are cancerous (malignant) and likely to spread, while others are noncancerous (benign).

How a polyp biopsy is taken depends on the location:

• EGD(esophagogastroduodenoscopy) or other endoscopy is used for the throat, stomach, and small bowel.
• Colonoscopy or flexible sigmoidoscopy explores the large bowel.
• Colposcopy-directed biopsy examines the vagina and cervix.

For areas of the body that are visible, a topical anesthetic is applied, and a small piece of the tissue that appears to be abnormal is removed. This tissue is sent to the laboratory, where technicians determine if the polyp is benign or malignant.

If the biopsy is to take place in the nose, or other visible surface or orifice, no special preparation is required, although fasting for a few hours beforehand may be advisable.

There is more preparation needed for internal procedures. Please see the particular procedure for additional information.

For superficial polyps, you may feel a tugging sensation while the biopsy is being taken. After the anesthetic wears off, the area may be sore for a few days. Biopsies of internal polyps are performed during procedures (for example EGD or colonoscopy), and usually nothing is felt during or after the biopsy. Please see the individual procedure topics for more specific information.

The test is performed to determine if the growth is malignant (cancer).

Examination of the biopsy shows the polyp to be benign (not cancer).

Malignant cells are present and may indicate a malignant tumor. Further tests may be needed.

Risks include:

• Bleeding
• Infection
• Organ perforation (hole)