General Information

• Vaccines are important to protect people from potentially severe infections - Allergies to vaccines are rare
• Some people are allergic to the vaccine itself or parts of the vaccine such as gelatin, egg and yeast
• Patients with an egg allergy can receive the flu vaccine but need to stay in the doctors office for 30 minutes after the injection
• During your allergy assessment your doctor will ask several questions about your reaction to determine if there is an underlying allergy to the vaccine
• The skin prick test (SPT) and intradermal test help confirm the allergy
• One week before the appointment, you / your child need to avoid antihistamines such as Benadryl, Reactine, Claritin, Aerus and Allegra because these medications will interfere with the test
• Many cough medications and decongestants also have antihistamines and should also be stopped one week before the appointment
• If antihistamines are not stopped one week before the appointment the testing may not be done
• The test can be performed on all ages including babies
• Two control samples are included to make sure that the test has worked:
  • One control will cause an itchy bump in all people
  • The other control is water and should not cause an itchy bump

Testing Procedure

• The SPT test is performed on the inside of the forearm but in some cases it may be carried out on another part of the body such as the back
• The steps for the SPT include the following
  • Cleaning the skin with an alcohol swab
  • A pen or marker will be used to label the skin and identify the allergens to be tested - Tiny liquid drops will be placed on the skin. There are usually 3 - 5 drops
  • The skin is then pricked through the drop using a metal device called a lancet
  • The doctor or nurse will return in 15 minutes to interpret the test
• The test may feel a little sharp but is generally not painful and does not cause any bleeding - Any allergies will cause a localized red bump that is itchy and usually appears within 5 to 15 minutes. These bumps are measured with a ruler by the doctor or nurse
• If there are no bumps with the SPT, the next step is the intradermal test which is usually 3 tiny injections under the skin. The doctor or nurse will return in 20 minutes to interpret the test
• If there are no bumps with the intradermal test, the next step is to give the vaccine
• You must remain in the clinic for 1 hour after the vaccine is given to make sure there are no reactions
• Possible reactions range from hives to anaphylaxis with symptoms such as skin swelling, breathing problems, vomiting and dizziness
• Treatment for reactions include antihistamines and epinephrine injection for severe reactions