Sniffles and sneezing due to allergies can feel just about as bad as a head cold. Skin rashes are so itchy, they can have you losing sleep. More often than not, the “triggers” to feeling miserable can include everything from dust and mold inside, to flower and tree pollen outdoors; from materials like latex (rubber), to medicines (like some antibiotics), not to mention laundry detergents or shampoos. Food allergies can also kick reactions into dangerous, sometimes life-threatening levels for some people. In any case, when symptoms are extreme, allergy testing for things that you may breathe, eat, or touch may help determine exactly what allergens are causing problems, and what to avoid.
Talk to your doctor about the symptoms you’re experiencing. He/she will take a detailed history from you before any testing even begins. Those options include:
Mild Skin Prick (“Scratch”) or Injection Tests
Mild skin prick or “scratch” tests can look at up to 40 different substances at once, and take only 20 to 45 minutes. Safe for most adults (done on the forearm) and children (done on the upper back), they may be used to diagnose sensitivities to things like allergic asthma, bee venom, food allergies, dermatitis (skin inflammation), latex (rubber), or penicillin. These tests are most reliable for testing airborne substances like dust mites, pet dander, and pollen. A histamine (a chemical that causes allergy symptoms), plus a thick liquid (glycerin) or a salt and water mix (saline) are also scratched onto the skin’s surface. If you don’t react to histamine, your test may not reveal an allergy (even if you have one). Most people have no reaction to glycerin or saline. If you do, you may have sensitive skin. When insect venom or penicillin are the concerns, a small amount of these allergens may need to be injected just under the skin’s surface.
More expensive (but less sensitive), blood tests may be advised if you’ve been known to have a severe or life-threatening (anaphylaxis) allergic reaction to even the tiniest amount of a substance.
Typically used to determine the cause of skin irritations like dermatitis, allergens are applied to patches that are placed onto the arm or back for 48 hours. (Avoid bathing or sweating during that time.)
If you’re allergic, the testing site will leave a raised, red, and itchy bump (like a bug bite) called a wheal (after about 15 minutes from a sin prick or injection test; after a few days from a patch test). These wheals will be measured and then cleaned with alcohol. With any type of test, the bigger the wheal, the more sensitive you are to the allergen.
Allergy testing isn’t always 100 percent accurate, and your results could also change at different times! Your doctor will go over the results with you, discuss any changes that you might need to make with your diet, your environment, or products that you might be using, plus talk about medications that you might need to take. (With any testing, be sure to have it done where emergencies like breathing problems or vomiting can be handled.)
While not perfect, allergy testing can play detective to help solve the puzzle of what’s ailing you!
By Lisa Miceli Feliciano
Sources include: www.mayoclinic.org