Allergy Testing for Teens

Allergies at Puberty

• People of all ages suffer from allergies. However, teen years are a period of increased risk for worsening allergies and development of new allergies, notes Cheryl M. Reifsnyder, Ph.D., in the informational brochure "Allergies and Hormones." This is presumably due to major hormonal fluctuations taking place. Hormones and the immune system -- the system responsible for allergic reactions -- are intricately connected. If a teen develops new allergic symptoms, allergy testing is important to get to the bottom of them; just because your child didn't have any or severe allergies, they might appear or worsen around puberty. On the positive side, allergies can also improve with the hormonal changes of puberty, so teen years are a good time to repeat positive allergy tests to see if allergies have been outgrown.

Concerns to Prompt Testing

• Teens may experience environmental or food allergies. The former are primarily triggered by contact or inhalation and the latter by ingestion, though contact and inhalation pose risks, too. Symptoms may include nasal or chest congestion, runny nose, watery or itchy eyes, coughing, wheezing, itchy throat, mouth swelling, difficulty breathing, hives, rash, itching, cramps, diarrhea, constipation, vomiting and anaphylaxis, which involves multiple organ systems. Keep an eye on teens, especially those with known allergies; they're less likely to communicate concerns, given the nature of many teen-parent relationships, those classic feelings of invincibility, their less cautious attitudes and their lack of enthusiasm for going to the doctor's. Also, teens with allergies might worry about being teased or bullied if they have to carry an epinephrine injector or suspect they'll otherwise stand out at school because of allergies.

Allergy Blood Testing

• Blood tests are one of two main types of allergy testing. They measure certain chemical responses to the introduction of allergens. They're a bit more expensive, less sensitive and require lab analysis, so take at least several days -- and often a week or more -- to offer results. However, they are the only option for teens who must be on an antihistamine regimen to control allergies, or who must take steroids or certain antidepressants. They are also generally the best option for teens with severe allergic skin conditions, certain heart conditions, poorly controlled asthma and those with a history of or the potential for life-threatening reactions to skin tests. Some teens may also prefer a single blood drawing to multiple pricks and drawn out sensations involved in skin testing.

Allergy Skin Testing

• Skin testing is the second main method of allergy diagnosis. Various methods, including needle pricks or injections, are used to introduce common allergens into the skin. The injections are shallow and generally not considered painful. Skin reactions can be observed often in about 20 minutes with a positive result. These are faster, cheaper and more sensitive than blood tests. To be reliable, though, they require your teen's system be completely clear of antihistamines, steroids and some other immunosuppressant drugs, which usually means they cannot be taken for a week or more before the test; follow your allergist's instructions.

Allergy Challenge Testing

• Neither blood tests nor skin tests are entirely reliable. Both produce false negatives and false positives with some regularity. They typically provide good starting points for identifying allergens in teens, but challenge testing is usually called for, too. This must be done with the supervision and advice of an allergist. Challenge testing involves deliberate withholding and reintroduction of suspected allergens. For example, if milk is suspect, your teen won't have any dairy products at all for a period of perhaps two to four weeks to see if symptoms clear up. Then, he'll eat a dairy product and you'll watch closely for four hours to see if any symptoms appear. Such empirical testing is the most reliable.