PREPARING FOR DIAGNOSTIC TESTING

Lung Function Tests
Bronchial Challenge Test
Skin Tests
Patch Tests
Oral Food Challenge
Oral Drug Challenge
Nasal Challenge

Lung Function Tests 

Lung function tests at premier allergy are non-invasive, and they give us a quick overview on how well your lungs are working.  These tests are computer-based with visual incentives, very much like an interactive video game.

SPIROMETRY

This test measures how open your airways are and how easily air flows through your airways.  You will be asked to fill up your lungs with a deep breath, then blow out very hard for 3-6 seconds into a tube that is connected to a computer.  You can choose to have visual incentives on the computer screen as you are doing the test to help you gauge how hard and how long you need to continue blowing.  Blowing out birthday candles is the most popular choice among our patients, but there are many other incentives in our system you can pick from. 


EXHALED NITRIC OXIDE (eNO)

With advanced medical technology, we can now measure inflammation in your airways using a small device that captures your exhaled breath, analyzes it, and reports the result within 2 minutes. 

Using results from eNO together with spirometry results, our provider will have a good understanding of how your lungs are functioning and map a treatment plan to help you breathe better.

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Bronchial Challenge Test

When you don’t get relief from your asthma medications, or when your symptoms don’t quite fit with asthma diagnosis, methacholine challenge can help clarify your diagnosis.  Our providers will recommend this test if they suspect that asthma may not be the cause of your symptoms.  Please see information on methacholine challenge and how to prepare for this test at the American Thoracic Society web site.

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Skin Tests

Skin tests have been used to diagnose allergies for more than 100 years.  They are easy, relatively non-invasive, and provide quick results.  Skin tests rarely cause side effects if performed after a careful evaluation of the patient.  As simple as skin tests may seem, there are variables that can cause inaccurate results.   Blood tests are not used very often but may be necessary in some cases to complement skin tests in order to obtain a more definitive result.  

There are 2 types of skin tests:

  • PRICK OR PERCUTANEOUS SKIN TEST:  There are no needles involved with this skin test.  A diluted allergen is applied using a small toothpick-like plastic device to lightly prick or touch the surface of the skin.  This test is used for environmental allergies, food allergies, and as the 1st step for testing for insect sting allergies and medication allergies.  
  • INTRADERMAL SKIN TEST: This test is only used as a 2nd step for insect sting allergies and medication allergies.  A very small and thin needle is used to deliver a tiny drop of a diluted allergen just below the skin surface.  

It takes about 10-15 minutes to apply allergens to your skin.  Then you will wait for 15 minutes before the test is read.  A small, red, and itchy bump similar to a mosquito bite will appear if the test is positive.  These bumps are measured in millimeters and recorded. Depending on how many positive results you have, it may take 10-20 minutes to complete the reading.  Our provider will create a treatment plan for you using the results from these skin tests.


HOW TO PREPARE FOR SKIN TESTS?

Some medications, including over the counter medications, may affect skin test results.  At the visit prior to skin testing, our provider will identify medications that need to be stopped including for how long they need to be stopped.  Please review this recommendation in your secured patient portal. If you are taking new medications, please let us know immediately.  In general, medications used to treat the following conditions can interfere with skin testing:

  • Allergic diseases and conditions 
  • Sleep disorders and insomnia
  • Cough and cold medications
  • Dizziness
  • Sinus disorders
  • Itching/rash 
  • Acid reflux
  • Headache/migraine

Please remember that this list serves as an example and is not an inclusive list of all medications that may interfere with skin testing.  For your safety, it is best that you discuss your complete current medication list with our provider at your first office visit with us.  Do not stop any medications without first speaking with your prescribing provider.

While most patients can successfully complete skin testing 3-5 days after discontinuing those medications that can interfere with testing, a few patients may require more time than is commonly expected.  If you require more time off your medication(s) to obtain reliable and valid skin test results, an additional office visit to repeat skin testing may be required.  


SKIN TESTING FOR FOOD ALLERGIES

Extra steps may be needed for certain food allergies, especially fruits and vegetables.  Skin testing to the actual food, in addition to standardized extracts may increase the accuracy of food allergy diagnosis.  At the visit prior to skin testing, our provider will discuss with you whether these steps are needed.  Only a small amount of each food is needed for skin tests (i.e. a thumb-size piece or one teaspoon).  Be sure to pack only 1 food in each bag or container with clear labeling.   A small Ziploc bag labeled with permanent marker works very well for this purpose.

For patients with eosinophilic esophagitis (EoE), our provider may recommend that you bring some food for skin testing after your first visit.  Only a small amount of each food is needed for skin testing (i.e. thumb-size piece or one teaspoon).  It is best that these foods are prepared without other ingredients added.  Below are examples of how best to prepare food for skin testing:

  • Egg (whole): hard boiled 
  • Cow’s milk
  • Corn: on the cob, fresh, or frozen
  • Rice: cooked 
  • Soy: edamame
  • Wheat: 100% wheat flour 
  • Beef: raw & poached in boiling water for 5-10 minutes
  • Chicken: poached in boiling water for 5-10 minutes
  • Tree nuts and peanuts: almond, Brazil nut, cashew, hazelnut, pecan, pistachio, walnut, and peanut (please do not bring in mixed nuts; these need to be individually packaged)

SKIN TESTING FOR DRUG ALLERGIES

Extra steps may be needed for skin testing to medications.  You may need to bring in some prescription medications for skin testing in addition to standardized extracts as this may increase the accuracy of drug allergy diagnosis.  At the visit prior to skin testing, our provider will discuss with you whether these steps are needed.  Please be sure to drop off these medications at least 48 hours before your skin testing visit.  For your convenience, some pharmacies may directly deliver medications to our office.  Please respond to the pharmacy’s request to process the prescriptions in a timely manner.  Your visit may be cancelled if we do not receive these medications in advance.


HOW LONG SHOULD YOU PLAN FOR THIS VISIT?

For skin test to environmental allergies or food, please plan for 45-60 minutes.  Allow for an additional 15-20 minutes to your appointment time if you bring in actual food for skin test as their extracts need to be prepared prior to the test. Skin tests to medications require 2-3 additional steps, so please allow for 60-90 minutes.


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Patch Tests 

Our providers recommend patch testing when allergic contact dermatitis is suspected as a possible cause of your symptoms.  It is reliable, easy to perform, and safe.  Our provider will determine which allergens may be involved based on your history and symptoms.  You may be asked to bring your own products for testing as well.

Since contact dermatitis is a “delayed” allergic reaction, your test results will need to be read over the course of 5 to 7 days.   Plan for 5 consecutive visits over the course of 7-10 days for patch testing.


HOW TO PREPARE FOR PATCH TESTING 

2 weeks before patch test application: 


  • Begin avoiding sunlight or use of a tanning bed on your back.
  • Wear dark tops if patch test is done in the summer time. 

1 week before patch test application: 


  • Stop using topical medications including steroids on your back. 
  • It is okay to take oral antihistamines such as Benadryl or Zyrtec.
  • Check your visit summary for any other medications that our provider may have asked you to stop in the week leading up to your test.

2 days before patch test application: 


  • Excessive hair on your back may make it difficult to keep the patches in place for 48 hours.  Shaving with an electric razor 1-2 days before testing helps.  
  • Do not use chemical hair removal products.

The day of patch test application: 


  • Shower the morning of the test since you cannot get your back wet for 48 hours after the patches are applied.  Do not put any creams or oils on your back after the shower.  Plan to arrive with a clean, dry back.
  • Wear old, dark clothing that you would not be upset if it becomes stained with the ink used to locate the allergens placed on your back.
  • Remember to bring any personal care products or other items or substances you’ve discussed with our provider during your consultation.   Only small quantities of product are required.  Be sure these items have clear labels, and where possible, each product should have a full list of ingredients.  Shampoo and soaps are not usually tested, but if this is an area of concern, please discuss this with our providers. 
  • If clothing is suspected, bring about a 1/2-inch square of the material, ideally taken from a seam or other unimportant area of the garment, that comes in contact with the affected skin.
  • Rubber gloves and footwear can also be tested.  Talk to our provider if you suspect that one of more of these items may be contributing to the problem.

After patch application: 


  • Avoid perspiration, heat, getting your back wet, and showering.
  • Avoid exercises that involve movements that may cause patches to come off.
  • Avoid sunlight or use of a tanning bed on your back.
  • Continue to use old and dark clothing.

After patches are removed until the final read:


  • Continue to avoid perspiration, heat, or getting your back wet except showering.
  • You may continue with light exercises that do not cause perspiration.
  • Continue to use old and dark clothing.
  • Always reframe the grids after you shower so that we can accurately identify the allergens for you.
  • Avoid scrubbing or touching the test site(s). 
  • Continue to avoid topical medications including steroids on your back. 
  • Continue to avoid sunlight or use of a tanning bed on your back.

PATCH TEST APPLICATION

This is the first visit of the series of visits associated with your patch testing.  During this visit, allergens are applied to your back.  These allergens are freshly prepared and placed in individual small square chambers.  These chambers are held together in a patch or a panel consisting of 10 chambers.  These patches are then taped to your back to allow the allergens to come in “contact” with your skin.  

Once you are checked in for this visit, we will begin filling the chambers with allergen since contact allergens lose their potency quickly and need to be applied immediately to the skin after the patches are prepared.  This process may take up to 20-30 minutes depending on the number of allergens being tested.  Please bring a book to read or homework to do as you wait.  Once all the patches are taped to your skin, you may return home.  

Itching and a burning sensation are common side effects. Try not to scratch the patch test area. Scratching can irritate your skin and may make the itching worse. It can also decrease your provider’s ability to interpret your test results. Try using pressure or applying a cold, dry cloth (no ice) to the affected area. 

Do not remove the patches unless you are experiencing significant discomfort.  Please call us immediately should that happen, and we’ll discuss next steps with you.  

If the patches become loose, you can use medical tape to reattach them to your skin. Apply the tape only around the outside edge of the patches.  

Please allow 30-45 minutes for this visit.


PATCH TEST REMOVAL

This is your 2nd visit in the patch test series.  It will take place approximately 48 hours after your 1st visit.  Our staff will remove all patches, check the integrity of the patches, re-mark the grid that identifies the allergens, and will then allow your skin to “air out” for 20-30 minutes before reading the reactions.  It usually takes about 15 minutes to complete the reading.  Positive reactions may range from a small skin rash with a little bit of swelling and itching to red, blistered skin.  Some of these reactions may be caused by irritation rather than allergy.  Please allow 30-35 minutes for this visit.


72-HOUR READING  


Our provider will meet with you during this visit.  Your reactions will be read, and the results discussed with you.  This visit usually takes 20-30 minutes.  Please allow 30-45 minutes for this visit.

5TH DAY READING  


A return visit on the 5th day after patch test application is essential to complete the results of your patch test.  Some allergens are known to take longer than 72 hours to show up as positive result.  Please be sure you remember to return for this visit.   Please allow 15-20 minutes for this visit.

ADDITIONAL READING. 


Our provider may recommend that you return for additional visits depending on your history and the initial results of your patch testing.  It is a good idea to keep the grid marks on your back for 7-10 days after your patch application.  If you see a new reaction in the test area after your last visit with us, take a photo with proper lighting, and call us.  Please allow 15-20 minutes for this visit.

Patch tests are safe.  Side effects are rare and are usually easy to treat.  If you have a strong positive result, you may develop blisters.  These will resolve over time once the patches are removed.  If they do not improve within 2 days of the patches being removed, please call us.  If an infection occurs, topical or oral antibiotic will be prescribed.  Positive reactions to certain allergens such as gold may persist for as long as a month.  Rarely, your skin color where patch tests are applied may change.  This usually normalizes after a few months but may be permanent.  Scarring is very rare (approximately 1 time for every 10,000 tests).

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Oral Food Challenge

Allergies to food can be “outgrown”.  Skin tests and blood tests help our providers decide whether you or your child is likely to have outgrown these allergies.  An oral food challenge is recommended when it is more likely than not that you or your child no longer has allergies.  It is important to remember that oral challenges need to be performed in a medical setting where life-threatening reactions can be quickly treated.  For your and your child’s safety, do not attempt these challenges at home.  Continue to strictly avoid food allergens until oral challenges are completed. 

A serving of the food will be given to you or your child over the course of approximately 1-2 hours.  Our team will be observing you or your child for any changes related to eating the food both during the challenge and for about 2 hours after the challenge.  Allow for 3-4 hours to complete the entire visit.

Oral food challenges are scheduled on Mondays or Wednesdays only.  Your appointment may begin at 9:15 am or at 1:15 pm on those days.

HOW TO PREPARE FOR AN ORAL FOOD CHALLENGE?

A week before the appointment: 


  • At your visit prior to the oral food challenge, our provider has identified medications that need to be stopped including for how long they need to be stopped.  Please review this recommendation in your secured patient portal.  If you or your child are taking new medications since the last visit, please notify us immediately.
  • Unstable asthma may increase your risk of reactions from oral challenges.  DO NOT stop your daily inhaled steroid asthma medications prior to oral food challenges.
  • Shop and prepare food for the challenge.  
  • It is best to prepare food for challenges at home, so you can better avoid cross contamination.
  • Cook the food allergen for the challenge by itself.  Avoid additional ingredients.  Poaching, boiling, or sautéing in safe oils work well.  Salt and pepper can be added.
  • If store-bought food is used, read the entire label to ensure that it does not contain or has cross contamination with other food allergens.
  • Prepare multiple options of the food in case your child refuses to eat something (i.e. nuts vs. nut butter).
  • Bring “vehicle” food, such as apple sauce, homemade smoothie, bread, or rice to mix food allergen in.  Condiments, such as ketchup, can be helpful.  It’s best to use food that you or your child has eaten before.  Be sure to check the labels of these foods for allergens. 
  • If the food allergen is mixed with other food ingredients, i.e. egg challenge using egg muffins, carefully record the amount of food allergens used in that entire batch.  Take care to divide the batch into small equal portions.
  • Don’t forget to prepare food for yourself if this appointment is for your child.  This is a long appointment, and you will not be allowed to leave our office until the challenge is completed.
  • Monitor you or your child’s health.  Cancel the appointment if you or your child is sick within 1 week leading up to the appointment, even if it is a minor cold.  You will not incur a rescheduling fee.
  • Bring activities of your choice to pass time during this appointment.  For pediatric patients, we designate 1 room for you and your child for the entire visit.  
  • Please complete the cooking process at home.  We only provide a microwave to reheat foods brought from home and a refrigerator and a freezer to keep food cold.

The day of the appointment:


  • Have a light meal on the day of the appointment.
  • Avoid eating or drinking for 2 hours prior to the challenge.
  • Avoid physical exertion 2 hours before and after the challenge.
  • Don’t forget to bring your prepared food with you on the day of your appointment.
  • Bring your epinephrine autoinjectors to the visit. Although extremely rare, a delayed reaction may occur.  The challenge visit will be cancelled if you don’t have epinephrine autoinjectors.  Cancellation fee will apply.

TIPS ON FOOD PREPARATION 

    MILK 


  • Consider cheese or yogurt in addition to liquid milk. 
  • Bring bottles or “sippy” cups, so your child can drink from something familiar. 
  • Also consider powdered milk which can be added to many foods. 

  EGGS 


  • Hard-boiled eggs work best.  
  • For a challenge of baked goods containing eggs, bake a batch of 6 muffins using 2 eggs.

SOY


  • Consider soy yogurt in addition to soy milk. 
  • You may also consider edamame or getting creative with tofu. 

WHEAT


  • Consider 2 slices of bread, a serving of whole wheat cereal, or cream of wheat.

PEANUT 


  • Finely ground peanuts can also be made into an ice cream Sunday.  Bring a small tub of ice cream and chocolate sauce.  
  • Creamy peanut butter.  Look for a brand that does not carry a “may contain tree nuts” label. The peanut butter can be spread on safe bread, crackers, celery, or any other safe vehicle.  

TREE NUTS 


  • You need a nut that is not contaminated with peanuts or other tree nuts.  Never buy nuts from an open bin.  Buy nuts in a pre-packaged plastic bags, and rinse them thoroughly under cold running tap water for 5-10 minutes.  Dry the nuts before cooking.  
  • You can grind the nuts and put them into safe homemade cookie, muffin, or brownie. 
  • Finely ground nuts can be sprinkled on top of pudding, yogurt, or ice cream if those foods are safe for your child. 
  • Our providers may recommend almond milk and cashew milk.  Read the label to ensure that there is no cross contamination with other nuts.

MEAT/ SEAFOOD 


  • A serving of meat/seafood is usually about the size of a deck of cards. 
  • Fish can be cross-contaminated if it is packaged or stored with other seafood. 
  • Don’t forget to bring condiments such as ketchup, mustard, or BBQ sauce if those foods are safe. 

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Oral Drug Challenge (Graded challenge) 

Allergies to medications can often be “outgrown”.  Skin tests help our providers decide whether you or your child is likely to have outgrown these allergies.  An oral challenge is recommended when it is more likely than not that you or your child no longer has allergies.  It is important to remember that oral challenges need to be performed in a medical setting where life-threatening reactions can be quickly treated.  For your and your child’s safety, do not attempt these challenges at home.  Continue to strictly avoid offending drugs until oral challenges are completed. 

This challenge is the final step for your drug allergy evaluation.  A 2-step dosing of the medication in question will be given to you or your child over the course of approximately 90 minutes.  Our team will be observing you or your child for any changes related to the medication both during the challenge and for 1 hour after the challenge.  Allow for 2 hours to complete the entire visit.

HOW TO PREPARE FOR AN ORAL DRUG CHALLENGE?

1 week before the appointment: 


  • Pick up the medication for your challenge from the pharmacy.  Call us immediately if you cannot obtain this medication.
  • At your visit prior to the oral drug challenge, our provider has identified medications that need to be stopped including for how long they need to be stopped.  Please review this recommendation in your secured patient portal.  If you or your child are taking new medications since the last visit, please notify us immediately.
  • Unstable asthma may increase your risk of reactions from oral challenges.  DO NOT stop your daily inhaled steroid asthma medications prior to oral drug challenges.
  • Monitor you or your child’s health.  Cancel the appointment if you or your child is sick within 1 week leading up to the appointment, even if it is a minor cold.  You will not incur a rescheduling fee.
  • Bring activities of your choice to pass time during this appointment.  For pediatric patients, we designate 1 room for you and your child for the entire visit.  

The day of the appointment:


  • Avoid eating or drinking for 2 hours prior to the challenge.
  • Avoid physical exertion 2 hours before and after the challenge.
  • Bring the medication for the challenge to your visit.  The challenge visit will be cancelled if you don’t have the medication.  Cancellation fee will apply.

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Nasal Challenge

Our providers recommend nasal challenges when “local allergic rhinitis” to environmental allergies is suspected, but skin test results do not match up with your symptoms.   


HOW TO PREPARE FOR A NASAL CHALLENGE?

2 weeks before the appointment: 


  • Monitor your symptoms.  Cancel the appointment if you are sick within 2 weeks leading up to the appointment.  You will not incur a rescheduling fee.

1 week before the appointment: 


  • At your visit prior to the nasal challenge, our provider has identified medications that need to be stopped including for how long they need to be stopped.  Please review this recommendation in your secured patient portal.  If you are taking new medications since the last visit, please notify us immediately.
  • Unstable asthma may increase your risk of reactions from nasal challenges.  DO NOT stop your daily inhaled steroid asthma medications prior to nasal challenges.
  • Monitor your symptoms.  Cancel the appointment if you are sick within 1 week leading up to the appointment, even if it is a minor cold.  You will not incur a rescheduling fee.
  • Avoid immunization.
  • Avoid using perfumes, candles, air freshener, essential oil diffuser, any scented products, or cleaning supplies.  
  • Avoid being around smokes from campfires, outdoor grilling, or smudging.

2 days before the appointment: 


  • Avoid alcohol consumption, smoking, or vaping.

The day of the appointment:


  • Avoid physical exertion 2 hours before and after the challenge.
  • Avoid coffee and spicy food.

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