An alimentary, or food, allergy can arise at any time in life and may persist from that point forward. Children tend to grow in and out of food allergies, but adults most often develop lifelong allergic sensitivities. This means older people especially should have suspected allergies diagnosed, because they face potentially fatal allergy symptoms anytime they ingest a problem food. Allergic reactions to foods may affect the airways and blood vessels, as well as the alimentary canal.
Function
Individuals form antibodies to certain proteins in foods. When they next encounter those foods, an allergic reaction to those alimentary proteins will occur. The Mayo Clinic reports this action cannot be reversed with drugs or allergy shots.
Features
According to the National Institutes of Health (NIH), the signs of food allergies appear in conjunction with the allergens' passage through the body. Thus, itching and swelling in the mouth and throat may begin first, followed by inflammation of the skin and nasal passages. Allergy symptoms in the stomach and intestines usually occur within an hour or so of eating the wrong food. Patients can also swiftly develop a rare allergic reaction called anaphylaxis that affects blood pressure and breathing.
Effects
The impact on the alimentary canal may be mild and temporary, or severe with recurrent allergy symptoms. Common itching, swelling and nasal congestion may be followed by nausea, vomiting, stomach cramps and diarrhea, the Mayo Clinic relates. As the throat and airways swell, breathing may become difficult. This may, in part, trigger anaphylaxis, which occurs when the blood vessels suddenly dilate and reduce blood pressure. Anaphylactic symptoms include light-headedness, weakness and abnormal pulse. Without emergency medical treatment, this condition can cause fainting, coma and death.
Identification
Patients who identify their allergy symptoms as signs of anaphylaxis should call 911 right away. Breathing problems, weakness and loss of consciousness might prevent a later call for help. The possibility of anaphylactic shock warrants a diagnosis and equipment with an epinephrine injector for patients with food allergies. The Mayo Clinic reports doctors may order skin tests, blood tests or elimination diets to determine the exact foods that cause allergic reactions in individuals.
Prevention
Treating an alimentary allergy requires diligent self-monitoring of everyday diets. The only way to prevent health problems is to avoid the food allergens. The Mayo Clinic encourages people with food allergies to always check the ingredients when purchasing foods at the grocery store. Some allergenic ingredients, however, may be listed under different names on food labels. Patients should ask their physicians for a list of food products that may contain "forbidden" food ingredients.
