If you find yourself with a headache soon after eating, it's time to suspect a food allergy. Besides the typical allergy responses, headaches are another symptom that your body is reacting to something you ate. Here is how this allergy process works, how you can get tested, and what treatment is available.

The Allergy Process

Your immune system reacts to foods in a similar fashion as when you're allergic to pollen or cat hair. When you eat a food to which you are allergic, your immune system releases substances that try to get rid of the allergen. You may have an increased salivary response, your throat and esophagus may constrict, your stomach may churn violently and you may get the headaches because of an elevated blood pressure.

The symptoms are normally short in duration, but they can be intense. People with an allergy to peanuts can have their throat constrict so much that they have trouble breathing. For minor allergies, the symptoms go away as the food is digested and moves through your system.

Testing for Food Allergies

There are two primary ways of testing for a food allergy:

Skin test - The allergy doctor places a small drop of fluid containing a concentrated form of the food on your skin. They then prick the skin under the drop with a tiny needle. Within a few minutes, you'll get results. If you are allergic to the food, you'll develop a small red bump or a rash where the prick was done.

Blood test - This may be done along with the skin test. It is also done on people who have a skin condition where the skin test cannot be done. The blood test looks for antigens that your immune system created in response to a particular food.

Narrowing Down the Food Allergen

These tests give a general idea of what you are allergic to. To get a specific answer, your doctor may have you do a challenge test. This requires you to start out eating a small amount of a food, and increasing the amount you consume over several days until you begin to have a response. Your doctor will have you do this will several foods so you'll know to which foods you're most vulnerable.

Treating Food Allergies

These allergies cannot be cured, but knowing what you're allergic to allows you to adjust your diet. Your options to deal with the allergy include:

• Taking medications that slow down or prevent a response to certain foods.
• Removing the food from your diet completely.
• Limiting the food in your diet to an amount that doesn't cause a reaction.
• Use a substitute for the food. For example, you may be allergic to cow's milk but can drink goat's milk.

For an allergy doctor, contact a company such as Asthma and Allergy Clinic.