How to Find a Food Trigger continued...
Skin testing. A doctor can take an extract of the food and use it to scratch the skin lightly. If the area swells up, it's a sign of an allergic reaction. However, sometimes it's not accurate.
Blood tests. RAST -- radioallergosorbent test -- can check for special cells in the blood that are signs of specific food allergies. Generally it’s less accurate than skin tests. Other lab tests can check for cells that trigger swelling.
Tracking down a food trigger can take patience and detective work.
Be methodical. Eliminate only one food at a time. If you ban dairy and gluten at the same time and symptoms get better, you'll have no idea which one made the difference. Use a food diary to record foods and symptoms.
Move slowly. Accommodating a food allergy isn't easy. And eliminating too many foods could also cut out important nutrients your child needs to grow and develop. So for your child's sake and yours, be certain before eliminating a food from your child's diet permanently. Work with your doctor. Remember that a positive skin test isn't reason enough to cut out a food -- lots of kids test positive for foods that don't really cause symptoms.
Keep using other treatments. Even if your child does have an eczema trigger food, cutting it out may not make the rash disappear. So continue the other treatments your doctor recommends -- like skin ointments, lotions, medications, and avoiding other allergens like dust mites, pollen, or pet dander.