Dr. Ellis @DrAnneEllis Dr. Justin Greiwe - Best practices for oral food challenges on infants - which patients and when?
Food allergy is a family disease, not an individual problem.
Huge social and psychological consequences to a food allergy diagnosis - some children will be home schooled, not allowed to go to sleep overs or birthday parties, avoid airplanes/sporting events. So we have to get this diagnosis right! Oral food challenges are the Gold standard for diagnosing food allergy - they are underutilized in clinical practice, unfortunately.
Why perform an oral food challenge?
Make the diagnosis
Monitor for resolution
Assess the status of tolerance to cross-reactive foods
Relieve parental or patient anxiety
Determine if patient is a candidate for oral immunotherapy
The Ultimate Goal is to accurately identify patients who will benefit from oral food challenge - it does require ingestion of a meal-sized portion of tested food prepared in usual state.
Kevin Parks MD @kparksmd Dr Greiwe: a test does not define allergy. We've heard this so many times yet clinical decision-making hasn't caught up... history + exam + tests = data needed to assess food allergy.
Carina Venter PhD RD @VenterCarina No need to avoid food allergens during pregnancy or lactation for prevention.
Dr. Ellis @DrAnneEllis Testing via skin prick test or in vitro tests have advantages and pitfalls
IgE to Ara H2 is a strong predictor of peanut allergy. High IgE levels of Gal d1 and Bos d8 associated with more persist allergy to egg and milk, respectively. Skin prick testing to food has a high negative predictive value but overall positive predictive challenge of only ~50%.
Many factors can affect the accuracy of a specific IgE - clear history of previous reaction - if IgE 0.36 to 2 kU/L, 44% of patients passed a challenge despite that history.
Younger age important -lower levels of allergen specific IgE have increased clinical relevance in young children - having concomitant environmental allergy can artificially drive up the food specific IgE level.
A survey of US allergist showed that 92% of practitioner felt there was a need to perform OFC in their practice, but a minority actually did them.
ACGME requirements now dictate that Allergy Fellows in Training need to participate in a minimum of 5 oral food challenges.
Late phase and biphasic anaphylactic reactions very rare following oral food challenge - my editorial opinion is because of the rapid administration of epinephrine at the first sign of concerns anaphylaxis symptoms during an OFC.
RDN @PeanutFarmers @PeanutRD And Dr. Greenhawt mentioned yesterday that quality of life improves regardless of whether individual passes or does not pass the oral food challenge.
Kevin Parks MD @kparksmd Broad panel in vitro food-specific IgE tests are NEVER a good idea!
In survey of allergists the 3 top reasons OFC's are not performed were lack of time, lack of staff, and lack of office space - not safety.
Dr. Ellis @DrAnneEllis Issues unique to infant challenges:
Appropriate portion sizes for age
Appropriate vehicles/food forms
Mixing vehicles infant has previously tolerate
Allow ample time to feed!!
Subtle clues for infant reactions - ear picking, tongue rubbing, putting hand in mouth more than usual, neck scratching, change in general demeanor (quiet/withdrawn, clingy, fussy).
Stopping Criteria for OFC have been published. Don't be a cowboy, known when to quit.
Critical to do an oral challenge before enrolling someone on oral immunotherapy. Don't go through the burden of OIT if the disease isn't there.
Katherine Anagnostou @PedAllergyDoc As food OIT develops there will be a high need and demand for oral food challenges.
Dr. Ellis @DrAnneEllis Exacerbations of skin disease related to food do exist, but nowhere near as commonly as patients/public believe.
Use the failed oral food challenge as a teaching point both during and after the reaction - our responsibility as allergists to reduce anxiety and fear - instill healthy respect for food without crippling parent and children. Instill Confidence not Fear in our food allergy patients - Empowerment not Despair. Ensure that food allergy does not define the patient.
Kevin Parks MD @kparksmd Primary teaching points for families with food allergy: confidence rather than fear, empowerment rather than despair. Lowering the psychosocial cost of food allergy should be a primary goal. Passing a food challenge should be followed by including the food in the child's diet. Recent data suggests they don't. Follow up is key.
Dr. Ellis @DrAnneEllis Dr. Benjamin Prince now discussing Practical Aspects of Infant (and toddler) oral food challenges.
Oral food challenges are a necessary procedure for any allergist who is going to be diagnosing food allergy.
Sometimes getting the patient to eat can be the most difficult and frustrating part of the challenge.
The good news about infant OFCS- most reactions are mild and cutaneous, only a few cases have required epinephrine in the RCTs.
Before you begin - counsel the family on how to prepare and what to expect - review what medications to stop and more importantly which ones not to stop (Asthma meds!). Send a written reminder prior to the day of challenge; reschedule if the child appears to be getting sick. Obtain written informed consent on the day of the oral food challenge.
Pre-draw up the medications that may be needed to treat a reaction; obtain baseline weight, vital signs and detailed physical exam.
A 5 yr retrospective chart review of children seen for peanut allergy who had 2 different skin prick tests at two different times - 2mm difference on average after 5 to 8 months (got bigger).
Important to consider both protein content and total volume of food. Protein content should mirror a normal meal sized portion.
Initial dose is usually base on overall risk of reaction - lower risk 5-10% of total dose, higher risk -0.1-1% of total dose.
Most clinic oral food challenges involve 4 to 6 doses; consider more gradual initial doses in patients planning on undergoing OIT later.
How much time between doses? typically 10 to 30 min - shorter time for lower SPT/sIgE, longer time with higher SPT/sIgE, history of wheeze/asthma or past severe reaction.
For the non-verbal patient it is critical to perform a good baseline physical exam and vitals.
Tips for feeding infants and toddlers - Vehicles are EXTREMELY important - applesauce, pudding, yogurt, ice cream, juices, baby food often successful. Encourage the family to bring favorite foods that can be combined with the challenge food. Encourage the family to try foods with similar textures at home prior to the challenge (e.g. the muffin for a baked egg or milk challenge without the egg or milk).
Minimize skin contact with food as much as possible.
Provide several food options at one time - a Bamba stick, a serving of peanut butter and a Reese's pieces to choose from, for example. Nut butters are the best way to do tree nut challenge as that's the source with the highest amount of protein compared to nutella for e.g. or almond milk for e.g.
Kevin Parks MD @kparksmd Feeling less like a loser allergist after this talk. Lots of kids who pass food challenge/have negative SPT/sIgE tests, green light to reintroduce the food at home, they come back a year later having NOT eaten the food! Good to hear the FA experts fight the same battle.
Dr. Ellis @DrAnneEllis Its why it's now 'part of the deal'. If the patient doesn't promise to eat the food after the challenge, I won't offer it. My 2 yr wait list for the oral challenges can't allow for this to happen.
Dr. Ellis @DrAnneEllis now Dr. Jay Lieberman - Prevention and Management of Infant Anaphylaxis. Foods are clearly the most common trigger for infant anaphylaxis. Food triggers in infants may vary by country/region - Peanut most common in Tennessee, whereas as Milk most common in Massachusetts.
If we are to prevent food induced anaphylaxis we must do our best to prevent food allergy - the Addendum guidelines for early introduction of peanut based on results from the LEAP trial are well known. There will be reactions in the low risk population. Not a lot - but they will happen. LEAP doesn't prevent ALL peanut allergy, just significantly reduces the risk.
Kevin Parks MD @kparksmd Lieberman: infant food challenges are annoying, "they suck", but we have to own them. It's our deal.
KristinSokolMD @kristinkrasnow If we are not doing oral food challenges, even in our infant patients, we are doing a disservice to our patients. - Dr. Leiberman.
Dr. Ellis @DrAnneEllis There is universal agreement that epinephrine is the first line therapy for anaphylaxis in infants. Dose is 0.01mg/kg (as will any other age group). One of the challenges of using an epinephrine autoinjector in an infant, however, is that they may be at risk for an intraosseous injection based on the needle length from ultrasound study.
Very important to hold the child still when administering an epinephrine auto injector - grasp the thigh firmly to avoid lacerations , pinch up the skin to ensure intramuscular injection. Remember dosing of epinephrine is weight based not age based!
Kevin Parks MD @kparksmd currently available 0.15mg epi AI's (US market) may hit bone in nearly 1/2 of infants based on skin-to-bone distance. We don't know the physiologic effects of intraosseous injection of epi vs IM or SC.
Dr. Ellis @DrAnneEllis Consider rephrasing a "failed" oral challenge as a "B+" - look what you WERE able to eat, not focusing on that the entire amount of food was not eaten.
Before you order any test for food allergy - ask your self (and the parents!) what you are going to do with the information. False positive tests are common. Greenhawt now doesn't allow parents to make their own muffins for baked challenges to ensure no cross-contamination with other food allergens.
No other specialty owns food allergy, drug allergy or anaphylaxis. We owe it to our patients to do the best for their allergic needs!
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