Published: August 2026
Medically reviewed by:
Gary Falcetano, PA-C, AE-C
Article summary: Testing with allergen components can improve the accuracy of peanut allergy diagnosis by distinguishing clinically significant allergy from cross-reactive sensitization, helping clinicians make more confident diagnostic and management decisions. Through the real-world story of NFL player Landon Robinson, this article explains how ImmunoCAP™ Specific IgE blood testing with allergen components supported an oral food challenge that overturned a childhood peanut allergy diagnosis, opening the door to opportunities that would otherwise have been unavailable.
How testing with allergen components changed one patient’s trajectory
A peanut allergy can be a life-changing diagnosis. It influences what patients eat, where they travel, the careers they pursue, and the opportunities they believe are available to them. That makes diagnostic accuracy especially important, yet peanut allergy remains one of the more challenging food allergies to evaluate. Sensitization does not always equate to clinically significant disease, and whole peanut allergen testing alone may not provide the complete picture.1,2
Specific IgE blood testing with allergen components can do more than improve diagnostic confidence. It can provide additional information clinicians need to make decisions that can profoundly impact a patient's quality of life. For one patient, it changed everything.
When Landon Robinson received the call that he had been drafted by the Cincinnati Bengals, it marked the culmination of years of discipline, perseverance, and athletic achievement. What few people realize is that years earlier, uncertainty surrounding a peanut allergy nearly altered his course.
Landon was offered a spot at the United States Naval Academy. However, his offer was rescinded due to his peanut allergy, which is often a disqualifying medical condition for military service.
When whole peanut allergen testing isn’t the whole story
When Landon was a young child, he was given a whole peanut allergen test and the result was positive. On its own, however, that result could not distinguish clinically significant peanut allergy from allergen sensitization due to cross-reactivity.3
That’s why his clinician ordered an ImmunoCAP™ Specific IgE blood test with allergen components.
The additional molecular information changed the clinical picture, indicating he was sensitized to less severe proteins within the whole peanut allergen. This provided the confidence needed to proceed with an oral food challenge, which confirmed peanut tolerance. That result allowed reinstatement of Landon’s appointment to attend the Naval Academy, where he went on to play Division I football before ultimately reaching the NFL.
Landon's story illustrates an important clinical principle: greater diagnostic precision can lead to better patient outcomes—not only medically, but personally, professionally, and psychologically.
How does testing with allergen components improve diagnosis?
Diagnosing IgE-mediated food allergy requires integrating patient history with evidence of allergen sensitization. While whole allergen extracts remain valuable first-line diagnostic tools to help rule in or rule out allergy, they may not always provide sufficient information to distinguish clinically relevant allergy from sensitization alone. 3
Allergen components represent a cutting-edge evolution in food allergy diagnostics by identifying IgE antibodies directed against individual allergenic proteins rather than the whole allergen extract. This additional layer of information can help provide insights into the potential severity of symptoms and improve diagnostic specificity, particularly for peanut allergy, where cross-reactivity with environmental allergens is common.3
One useful analogy is cholesterol testing.
Years ago, clinicians relied primarily on total cholesterol. Today, evaluating HDL and LDL has become standard because understanding which cholesterol fractions are elevated leads to better clinical decisions.
Peanut allergen components provide similar clinical insight. Rather than knowing only that a patient is sensitized to peanut, clinicians can identify which peanut proteins are driving that sensitization—and what that pattern may suggest about clinical risk.
You can find test codes for ImmunoCAP Specific IgE tests with allergen components from your preferred laboratory in our Lab Ordering Guide.
What do peanut allergen components tell clinicians?
Each peanut contains multiple allergenic proteins, and not all carry the same clinical significance.
- Ara h 1, Ara h 2, Ara h 3, and Ara h 6 are storage proteins that are heat- and digestion-stable. Sensitization to these proteins, particularly Ara h 2, has consistently been associated with a higher likelihood of a true peanut allergy and systemic reactions.2
- Ara h 8 belongs to the PR-10 protein family and shares significant homology with the major birch pollen allergen Bet v 1. Sensitization to Ara h 8 often reflects cross-reactivity in patients with birch pollen allergy and is commonly associated with pollen food allergy syndrome (PFAS), also known as oral allergy syndrome (OAS), rather than primary peanut allergy.2
- Ara h 9 is a lipid transfer protein (LTP). Its clinical significance varies geographically and should always be interpreted alongside the patient's history and other component results.2
- Bet v 2, a birch pollen profilin, is another cross-reactive protein that may indicate sensitization driven by environmental pollen exposure rather than clinically significant peanut allergy.4
Importantly, component results should never be interpreted in isolation. Instead, they complement the clinical history and other diagnostic findings to support more informed decision-making.¹
Landon's results: the details that kept him in the game
Landon's whole peanut-specific IgE measured 14.0 kUA/L. Viewed alone, many clinicians would understandably consider this result concerning enough to avoid recommending an oral food challenge.
However, his allergen component profile told a different story. His results demonstrated:
- Whole peanut-specific IgE: 14.0 kUA/L
- Ara h 8: 12.2 kUA/L
- Bet v 2 (profilin): 18.9 kUA/L
- Low-level sensitization to Ara h 9
- Negative to Ara h 1, Ara h 2, Ara h 3, and Ara h 6
This pattern suggested sensitization driven primarily by birch pollen cross-reactivity and other lower-risk proteins rather than sensitization to the major peanut storage proteins most strongly associated with systemic reactions.
That additional information provided reassurance for the clinician, Landon, and his family to proceed with an oral food challenge. The challenge confirmed peanut tolerance, and they were able to remove his pre-existing peanut allergy diagnosis. Dive into the details of peanut allergen components test results with our peanut test results interpretation guide here.
The right allergy diagnostic test at the right time
Landon's experience also demonstrates why whole peanut-specific IgE alone cannot tell the complete story.
His brother, Lawson, has a clinically significant peanut allergy. Both brothers are sensitized to peanuts, but their molecular sensitization profiles—and therefore their clinical outcomes—are fundamentally different. Without testing with allergen components, those important differences would have been difficult to recognize.
For clinicians, this reinforces an essential point: two patients with positive peanut-specific IgE results may require very different counseling, management, and follow-up. Knowing which proteins are involved often provides clinically meaningful information that can support individualized patient care.
What testing with allergen components means for clinical practice
Testing with allergen components is no longer reserved exclusively for allergy specialists. Primary care clinicians, pediatricians, and other providers who evaluate patients with suspected food allergy can order and incorporate these results into their diagnostic workup when interpreted within the context of a thorough allergy-focused history.
Patients who may particularly benefit include those who:
Have discordant history and whole allergen-specific IgE results
Have positive peanut-specific IgE without a convincing history of clinical reactions
Have suspected pollen food allergy syndrome
May be candidates for referral for an oral food challenge
Could benefit from reevaluation after years of peanut avoidance .
Current international guidelines emphasize that testing with allergen components should complement—not replace—clinical assessment and, when appropriate, an oral food challenge, which remains the reference standard for diagnosing food allergy.1
Fortunately, clinicians do not need to interpret component results alone. Interpretation guides and evidence-based resources are available to help translate laboratory findings into clinically meaningful decisions.
The full picture of an allergy means better patient outcomes
For Landon, testing with allergen components represented far more than another laboratory result. It helped restore an opportunity that once seemed permanently out of reach.
He attended the United States Naval Academy, competed at the highest level of college football, traveled with confidence, discovered he could safely eat peanut butter, and eventually became an NFL draft pick.
Most patients will never play professional football. But every patient has opportunities that can be affected by diagnostic uncertainty—whether it’s military service, career choices, travel, school, family meals, or simply living without unnecessary dietary restrictions.
When patient history suggests a possible IgE-mediated food allergy, a specific IgE blood test with allergen components can provide clinically meaningful information that supports more confident diagnostic decisions and, ultimately, better patient outcomes.
Also consider whether patients with longstanding peanut avoidance or whether those with diagnostic uncertainty may benefit from reevaluation using a specific IgE blood test with allergen components.
