Bridging the Diagnostic Gap in Allergy Care

Nearly one in three U.S. adults and more than one in four U.S. children report having a respiratory allergy, eczema, or food allergy. However, up to 35% of people self-diagnose food allergy or intolerance to foods and self-manage the condition, rather than seek a clinical diagnosis from a healthcare professional. Individuals who self-diagnose may take action like adopting restrictive diets that can cause avoidable nutritional gaps, spending money on ineffective supplements, or taking antihistamines unnecessarily, all while the root cause of their symptoms remains unaddressed.

While allergy self-diagnosis or misdiagnosis can have negative or harmful impacts on patients’ allergy care, failing to test for all suspected allergens can also leave allergies undetected, leading to avoidable symptoms and a worse quality of life for patients. Underdiagnosed allergies can also put patients at risk for unexpected reactions, repeated emergency visits, heightened anxiety around uncertainty, and unnecessary treatments for presumed allergies. 

Beyond individual risk, underdiagnosis drives a higher economic burden of allergies on the healthcare system, resulting in potential billions each year in wasted healthcare spending. By getting to the root cause of patients’ allergies with detailed symptom histories from patients coupled with history, informed comprehensive allergy testing can help uncover hidden allergies, ensure both effective care and smarter resource utilization, and improve patient safety.

How clinicians can accurately confirm a suspected allergy

Skin-prick testing and specific IgE (sIgE) blood testing, the two proven tests that healthcare providers typically turn to, don’t necessarily indicate a clinical allergy, but rather sensitization to an allergen. With sIgE blood testing, people who produce elevated sIgE antibodies that can recognize a specific allergen are described as being sensitized to the allergen, and having an increase in sIgE is correlated with an increased likelihood of having an allergic reaction when exposed to that allergen. However, sensitization doesn’t guarantee that the person will have an allergic reaction. In the case of food allergies, it also doesn’t indicate that a food should be removed from a patient’s diet, especially if the patient is currently eating the allergen without problems.

Additionally, not every person who is allergic to one food is allergic to the same component of that food. For example, patients with peanut allergies may be sensitized to different proteins. By identifying the specific proteins, or allergen components, to which a patient is sensitized, clinicians may be able to predict how they will express their particular symptoms, which enables more precise guidance for patients in the management of their allergies. This is especially important in helping patients understand when they’re likely to experience less severe symptoms like an itchy mouth versus a more systemic or even anaphylactic reaction, or if the patient can potentially ingest a cooked form of the allergen. 

Because of this variability, capturing a patient’s clinical history is the most important step of the diagnostic process. A thorough patient history should assess symptoms consistent with IgE-mediated allergy, which can affect the skin, gastrointestinal tract, cardiovascular system, and/or respiratory tract. These reactions typically occur within minutes to a few hours after allergen exposure, except for certain delayed responses, such as those seen in alpha-Gal syndrome, a mammalian meat allergy. Clinicians should assess when symptoms occur, their frequency, and potential triggers, taking into account factors such as work, home, and eating habits to help identify possible allergies. Reactions should also be consistently reproducible under similar conditions to support an accurate diagnosis.

Getting to the root cause of a patients’ allergy symptoms helps clinicians provide patients with the appropriate treatment, whether it’s medication, lifestyle modifications, or allergen-specific immunotherapy, to improve their health outcomes and overall well-being.

Negative impacts of underdiagnosis on the patient and healthcare system

Underdiagnosis or delayed diagnosis of a suspected food allergy not only creates harmful impacts for patients, but it also creates a negative impact on the healthcare system. For patients, the financial impact of acute reactions and anaphylaxis is considerable.

A seven-year retrospective analysis of insurance claims for 355,520 individuals with food allergies found that 17% had a food allergy-related emergency department visit and 0.9% were hospitalized. The study also estimated that patients with food allergy-related visits incurred an average out-of-pocket cost of $1,631 per year, representing roughly 11% of the total annual cost of $14,395 per patient for outpatient, emergency, and hospital services. Following hospital visits, one analysis found that the majority of patients who visited the emergency department for an acute allergic reaction or anaphylaxis were not given a prescription for an epinephrine autoinjector, educated about avoiding the offending allergen, or advised to consult with an allergist. 

From a healthcare resource utilization perspective, allergic conditions such as hay fever, eczema, food allergies, and allergic asthma are common yet frequently underdiagnosed and undertreated, placing a significant burden on the healthcare system and leading to avoidable health complications. Systemic healthcare inequities can also exacerbate the impacts of underdiagnosis. One study found that the prevalence of food allergy among Medicaid-enrolled children across the U.S. was substantially lower (0.6%), compared to previous national estimates using parent surveys (7.6%) and reports of physician confirmation of food allergy (4.7%), pointing to prevalent underdiagnosis in this patient population.

Overall, food allergies are a major driver of healthcare costs, with one study estimating that childhood food allergies cost the United States $24.8 billion annually, largely due to inpatient, outpatient, and emergency department visits, pointing to the importance of early and accurate diagnostics.

Why the right diagnostic approach matters

Obtaining an accurate food allergy diagnosis can increase dietary diversity and potentially improve nutrition when suspected allergies are ruled out, making the correct diagnostic approach essential from the start. Greater diagnostic specificity may also allow clinicians to reduce the number of higher-risk oral food challenges while performing more lower-risk challenges, helping more patients reach an accurate diagnosis. 

By using the right diagnostic approach and ensuring that patients have an accurate and thorough understanding of their allergies, disease management can shift from reactive to proactive, leading to better care, less unnecessary resource utilization, and improved quality of life for patients.

Photo: HASLOO, Getty Images

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