What to Expect

Allergy testing

Skin testing

Skin testing is one of the most common and reliable ways to test for environmental and food allergies. These tests are not very invasive, and results are available in about 20 minutes.

A prick test is when a diluted allergen is applied using a small, disposable plastic device to prick the surface of the skin. Side effects include redness, swelling, and itching at the prick site.

Do not take antihistamines before skin testing. Please do not stop any antibiotics, asthma inhalers, or steroid nose sprays before skin testing.

These antihistamines must not be given for 48 hours before skin testing:

  • Chlorpheniramine (Diabetic Tussin and ChlorTrimeton)
  • Clemastine (Tavegyl)
  • Cyproheptadine (Periactin)
  • Dexchlorpheniramine (Polaramine)
  • Diphenhydramine (Benadryl)
  • Hydroxyzine (Atarax)
  • Promethazine (Phenergan and Phenadoz)
  • Tripelennamine (Pyribenzamine)

These antihistamines must not be given for five days before skin testing:

  • Azelastine nasal spray (Astepro and Astelin)
  • Cetirizine (Zyrtec)
  • Fexofenadine (Allegra)
  • Loratidine (Claritin, Alavert)
  • Levocetirizine (Xyzal)
  • Desloratadine (Clarinex)

If you have any questions regarding your appointment, please contact us.

Blood testing

Another method of testing for allergies is blood tests. Blood is drawn from a vein and sent to a lab, and results are available in approximately a week. Lab tests can look at antibodies to specific allergens, like grass pollens, or antibodies to specific allergenic proteins, especially in foods.

Allergy shots

Allergy shots are unique to each patient and contain a small amount of the allergens that a child is allergic to. Allergy shots are administered every week. We start by administering a very small amount of diluted allergen and gradually build up the dose weekly.

Please plan on bringing your child to a weekly allergy appointment for approximately six months. Once your child receives all injections in the buildup phase, we will maintain your child’s tolerance with monthly shots at the child’s highest dose tolerated.

Please note:

  • Allergy shots should be given once a week in the same clinic location.
  • Patients and their parent/guardian must wait at least 48 hours between each injection.
  • Over the first year, patients receive approximately 25 allergy shots weekly, then a monthly allergy shot for three to five years.
  • If more than 14 days pass between each injection, we repeat or decrease the dose.
  • Your child must wait 30 minutes after each injection and be evaluated by an RN before leaving the clinic. If you cannot wait 30 minutes, please reschedule the shot for a different day.
  • You are required to bring an epinephrine auto injector to each allergy shot appointment and carry it for the remainder of the day.
  • Skip your weekly allergy shot if your child has been sick with a cold, flu, or fever, or if your child is having an asthma exacerbation.

Food challenges

An oral food challenge appointment involves eating measured doses of the allergic food every 15 minutes in a slow, graded fashion. These visits last three to four hours.

The doctor will prescribe three to seven graded doses of the allergic food. He or she will start with a very small dose that is unlikely to trigger any symptoms. With each dose, the doctor and/or registered nurse will assess for any signs of a reaction. If no symptoms or adverse reactions are noted, the nurse will give the next prescribed dose (slightly larger than the previous dose). After the last dose is given, you child will be observed for at least one hour prior to discharge.

The oral food challenge will stop if your child develops a mild or severe reaction during the challenge.

Additional information:

  • You are responsible for bringing in the food your doctor has recommended to challenge (for example, nut butter, baked egg muffin, scrambled egg). Please see egg and dairy recipe options below.
  • Please do not give your child any antihistamines for a minimum of five days prior to the food challenge. Continue all asthma medications on the day of the challenge.
  • Please do not give your child the food to be tested for prior to the appointment.
  • You will be scheduled to see the nurse conducting the food challenge in addition to the doctor who ordered the food challenge.
  • Please bring your child’s current epinephrine auto-injector with you to the appointment. This is required in the event that your child develops an allergic reaction after being discharged from the appointment.
  • We recommend only very small amounts of food two hours prior to the oral food challenge to ensure that your child eats the prescribed doses during the appointment. Small snacks/breastfeeding prior to the appointment are OK. You may bring additional food that your child eats regularly without concern (such as applesauce, crackers, or juice).
  • Please ensure that your child is healthy—call to reschedule if your child is sick, is experiencing an asthma flare-up, or is currently on prednisone or any antibiotic.
  • Feel free to bring age-appropriate activities to pass the time during the challenge.

Please call us at (650) 725-7233 if you have any questions about food challenges.

Recipes for food challenges