Updates and Tips in Allergy and Immunology

Educational Objectives

The goal of this program is to improve diagnosis and management of allergies. After hearing and assimilating this program, the clinician will be better able to:

1. Optimize use of the oral food challenge in patients with food allergies.
2. Compare epinephrine blood concentration in nasal spray with injection in emergency treatment of anaphylaxis.
3. Cite health disparities among various ethnic groups in anaphylaxis.

Summary

Food allergy: major food allergens (usually proteins) are recognized by serum immunoglobulin (Ig) E antibodies in >50% of people with allergies; this indicates that if someone has a food allergy, they are likely sensitized to one of these major allergens; allergy refers to an immunologic reaction, not intolerance; mechanism of allergy — an individual develops sensitivity to an allergen and produces IgE antibodies, which do not necessarily cause a clinical reaction; however, upon subsequent exposure, the antibodies bind to the allergen and the mast cells, causing a series of reactions that release inflammatory chemical mediators (eg, histamine, tryptase, prostaglandins, leukotrienes); anaphylaxis — can manifest in various ways and may involve the heart, lungs, skin, and gastrointestinal (GI) tract; in food allergies, it typically presents with swelling of the mouth, throat, as well as face, nausea, vomiting, and diarrhea; many patients also experience significant urticaria

Current updates in food allergy: women may experience uterine cramps as a sign of anaphylaxis; this might be because of prostaglandins causing smooth muscle contraction; in 2023, the United States expanded its list of food allergens to 9 by adding sesame; for children, the most common major allergens include egg, milk, soy, wheat, peanut, and tree nuts; ≈60% of children outgrow allergies to egg, milk, soy, and wheat, but most children with peanut and tree nut allergies tend to retain till adulthood; allergies to shellfish and fish are increasing among adults; shellfish accounts for ≥50% of new-onset food allergies in adults; sesame can cause allergic reactions in children and adults; these allergens account for ≈95% of major food allergy reactions, but there are >160 foods known to cause allergies

Winter-Spring tree pollen: often comes from the cedar, cypress, and juniper families; these can cause allergic rhinitis, asthma, and conjunctivitis; because they are closely related, an individual allergic to one is likely allergic to all; pollen blooms can start as early as December, and depending on the location, they may last well into the spring

Component diagnostics: peanut allergy affects 1% to 2% of the population, ie, 3 to 6 million people in the United States; blood and skin tests are used to detect IgE antibodies to peanut proteins; component diagnostics examine the molecular components of these allergens, providing improved diagnostic accuracy to help stratify risk; it is now becoming possible to predict who might or might not outgrow peanut allergies in adulthood; eg, antibodies to Ara h 2, a component of peanut protein, indicate that a child is likely to develop severe anaphylaxis and may not outgrow the allergy; the presence of IgE antibodies to Ara h 8 indicates a milder condition, as this particular allergen is more closely related to birch pollen; heat-labile proteins may cause mild symptoms, and allergies might be outgrown; heat-stable proteins associated with Ara h 2 can cause issues throughout the entire GI tract; this information helps in educating patients and setting expectations; some ongoing studies are also focusing on foods other than peanuts

Allergy vs intolerance: history is crucial for distinguishing between allergy and intolerance; symptoms of intolerance (eg, abdominal pain, bloating, diarrhea) can overlap with those of food allergy but are not mediated by the immune system (and do not cause anaphylaxis); intolerances can still be very serious (eg, celiac disease)

Allergy testing: based on the patient’s history, determine which specific allergens should be tested for using skin or IgE testing; rarely, the history and appropriate testing may not provide clarity; the gold standard for diagnostic testing is the oral food challenge, which should be performed under the supervision of an allergy-immunology practitioner trained to manage anaphylaxis

Management: omalizumab injections have been newly approved for reducing food allergic reactions in multifood allergic individuals; the medication reduces the severity of reactions; however, the speaker expresses concern about administering new and expensive biologic agents to infants and young children for an indefinite period; the speaker also believes the reason for the increase in food allergies and other types of immune dysregulation needs to be identified; an oral peanut immunotherapy was approved in early 2020; this powder is standardized to contain exact quantities of different proteins, ensuring that each exposure for the allergic individual delivers consistent amounts of same proteins (unlike the variable doses in real peanuts); the initial doses are given in an allergy-immunology clinic, after which the patient can start treatment at home; it helps to desensitize the immune system; although it does not cure peanut allergy, it can help reduce the reactions in the majority of patients

Spring tree pollen: oak variants may look very different, but allergies to multiple types are common; oak pollen is a major allergen in Northern California and other regions; it is important for patients to be able to recognize these trees

Epinephrine for anaphylaxis: injection — hold the epinephrine needle around its base, rather than the top; this reduces confusion and prevents accidental injection into the finger; another injection system (Auvi-Q) provides verbal instructions; there is also a generic injection system available; nasal sprays — are familiar for many patients with allergies, and some may be afraid of needles and injections; a new epinephrine nasal spray (Neffy) was approved by the US Food and Drug Safety Administration (FDA) for the emergency treatment of allergic reactions (eg, food allergies, bee stings, medications); studies reported that epinephrine blood concentrations from this spray are comparable to those from injections, with similar increases in blood pressure and heart rate; it is approved for individuals >66 lb; the prescription comes in 2 single-dose containers; administer the first dose through one nostril when anaphylaxis is suspected; if there is no improvement within 3 to 5 min, administer the second dose (one dose per container); the spray cannot be used in individuals with obstructed nasal passages (nasal polyps, trauma from boxing); look inside the nose before prescribing; use caution for individuals with a history of adverse reactions to sulfites (eg, cough or nasal congestion); information on the cost is not yet available

Nasal spray in the inpatient vs outpatient setting: nasal spray may be more practical for the outpatient use, as clinicians can interview and examine patients in that environment; in an inpatient emergency setting, it is quicker to inject epinephrine, which is readily available in crash carts along with needles; the real-world efficacy and ease of transport, and use are yet to be determined

Health disparities in anaphylaxis: minority patients have lower odds of receiving a diagnosis but higher odds of experiencing food-induced anaphylaxis; epinephrine is less available in schools with low-income students, and these patients are less likely to have anaphylaxis action plans that they or their caregivers can use; Black and Hispanic individuals have higher rates of emergency department visits; self-reported food allergies are sharply increasing across the board, with the highest rates among non-Hispanic Black children; Black and Hispanic children are at higher risk for adverse outcomes from food allergic diseases; the allergy community is actively working to improve equity

Spring-Summer tree pollen: olive tree pollen is a common allergen; if local privet bushes are blooming, allergic individuals may also experience symptoms, as privet and olive trees are closely related

Chronic nasal congestion: for individuals with chronic nasal congestion (unilateral or bilateral), establish the diagnosis by examining the nose and nostrils; if they appear flattened, the individual may have congestion caused by a genetic predisposition to nasal-valve collapse, which can obstruct nasal breathing (the valves collapse inward upon inhalation); assess for mucosal conditions (eg, nasal polyps) or structural changes (eg, broken nose); the most common cause is postrhinoplasty effects that lead to obstruction via the nasal valves; ask the patient to pull the nose laterally and gently inhale; if this clears the congestion, it indicates valve obstruction; another method is to ask the patient to pull the tips of the nostrils upward and outward to see if this relieves the congestion; these patients do not require allergy medications; nasal strips, especially at night, are useful; some patients may need an otolaryngology consultation

Atopic dermatitis: atopic dermatitis, commonly known as eczema, is caused by allergies; consumption of high-sodium foods leads to high levels of sodium in the skin; this can drive T lymphocytes to the allergy end of the spectrum and causes immune dysregulation in the skin; a large cross-sectional population cohort study used urine sodium as an indicator of consumption and found that higher levels were associated with a higher frequency of diagnosis, more active atopic dermatitis, and increased severity; another study in the United States using dietary recall reported that an additional 1 g sodium/day was associated with higher risk of current atopic dermatitis (adjusted odds ratio, 1.22); consider asking patients with atopic dermatitis about their diet

Long COVID-19 update: symptoms of long COVID-19 include brain fog, postexertional malaise, nausea, abdominal pain, diarrhea, persistent pelvic pain, menstrual issues; the highest-risk patients are the elderly and unvaccinated with severe infections, as well as those with preexisting conditions; symptoms can last for months to years; research shows that there is evidence of abnormal immune response among patients with long COVID-19; a recent study reported evidence of persistent T-cell activation in the blood, gut, spine, and lungs using positron emission tomography with an agent that highlights and indicates T cell activation; there is evidence of double-stranded RNA in biopsied gut tissue, suggesting ongoing viral activity; there were particularly high levels in the gut and spine in the people with the most significant long COVID-19 symptoms; this T-cell activation was noted ≤2.5 yr after infection; tissue-based immune activation and viral persistence seem to be contributors to long COVID-19

Readings

Ellis AK, Casale TB, Kaliner M, et al. Development of neffy, an epinephrine nasal spray, for severe allergic reactions. Pharmaceutics. 2024;16(6):811. doi:10.3390/pharmaceutics16060811; Ghouri H, Habib A, Nazir Z, et al. Omalizumab for the reduction of allergic reactions to foods: a narrative review. Front Allergy. 2024;5:1409342. doi:10.3389/falgy.2024.1409342; Klemans RJ, Broekman HC, Knol EF, et al. Ara h 2 is the best predictor for peanut allergy in adults. J Allergy Clin Immunol Pract. 2013;1(6):632-8.e1. doi:10.1016/j.jaip.2013.07.014; Mohamed S, Emmanuel N, Foden N. Nasal obstruction: a common presentation in primary care. Br J Gen Pract. 2019;69(689):628-29. doi:10.3399/bjgp19X707057; Mothes N, Horak F, Valenta R. Transition from a botanical to a molecular classification in tree pollen allergy: implications for diagnosis and therapy. Int Arch Allergy Immunol. 2004;135(4):357-373. doi:10.1159/000082332; Peluso MJ, Ryder D, Flavell RR, et al. Tissue-based T cell activation and viral RNA persist for up to 2 years after SARS-CoV-2 infection. Sci Transl Med. 2024;16(754):eadk3295. doi:10.1126/scitranslmed.adk3295; Peters RL, Krawiec M, Koplin JJ, et al. Update on food allergy. Pediatr Allergy Immunol. 2021;32(4):647-657. doi:10.1111/pai.13443; Tepler E, Wong KH, Soffer GK. Health disparities in pediatric food allergy. Ann Allergy Asthma Immunol. 2022;129(4):417-423. doi:10.1016/j.anai.2022.04.022.

Disclosures

For this program, members of the faculty and planning committee reported nothing relevant to disclose.

Acknowledgements

Dr. Gundling was recorded at Primary Care Medicine: Principles and Practice, held October 16-18, 2024, in San Francisco, CA, and presented by the University of California, San Francisco, School of Medicine. For more information on upcoming CME activities from this presenter, please visit https://virtualce.ucsf.edu. Audio Digest thanks the speakers and the presenters for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 1.50 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

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Lecture ID:

IM721501

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.