Allergic rhinitis and asthma: From nasal symptoms to accurate diagnosis

Imagine a patient whose life is disrupted by persistent sneezing, nasal congestion and a constant runny nose. Meet Natasha, an example of a young woman struggling with the relentless symptoms of allergic rhinitis. In this illustrative case study, see how the gold standard of in-vitro allergy diagnostics¹ from Thermo Fisher Scientific helped inform an accurate diagnosis.

Medication history

• Previously prescribed intranasal beclomethasone, but stopped due to subsequent epistaxis
• Currently takes inhaled beclomethasone, twice daily BID
• Uses intranasal antihistamines and nasal decongestants

Observation

Whilst observing Natasha during the consultation, her clinician observed frequent sniffing, nose rubbing and mouth breathing. 

How should Natasha's clinician continue the diagnostic workup?

Based on Natasha’s clinical history, a diagnosis of rhinitis may be made. The next step in the diagnostic process is a physical examination, including inspection of the face, and internal examination of the nose. All patients with persistent rhinitis should also be assessed for possible asthma; this should consist of a chest examination and lung function tests including spirometry or peak flow.²

To determine whether Natasha's rhinitis is allergic or non-allergic in origin, a specific IgE blood test or skin prick test (SPT) should be used. However, in Natasha’s case, SPTs are contraindicated due to her documented dermatographism, making a specific IgE blood test most suitable.² One study found that compared with a clinical history and physical examination alone, additional use of a specific IgE blood test increases diagnostic certainty by 64 percent.³

*Based on a prospective multicenter study of 380 children aged <6 years with symptoms of eczema and/or wheezing/asthma and/or rhinitis.³

Examination, investigations and results

Examination

Natasha’s GP continued the diagnostic process with a physical examination. Inspection of her face was unremarkable, but internal examination of her nose revealed turbinate hypertrophy with clear secretions. 

Examination of Natasha’s chest revealed no obvious abnormalities and chest expansion was equal on both sides. Her respiratory rate was 18 breaths/min and upon auscultation of her lungs, the GP heard a mild expiratory wheeze. 

Investigations

Next, the GP decided to request a specific IgE blood test. Based on Natasha’s symptoms, age and local sensitisation patterns, an appropriate panel of environmental allergens was selected. 

Differential diagnosis

What is the most likely reason for Natasha’s nasal symptoms?

Specific IgE blood test results will indicate whether the patient is sensitised (has IgE antibodies) to specific allergens. Specific IgE values of ≥0.10 kUA/L indicate sensitisation⁴  and the probability of allergy rises with increasing specific IgE antibody concentrations.⁵ Results should always be interpreted in conjunction with the clinical history and physical examination.^2,6 When test results are concordant with the clinical history, a diagnosis of allergic rhinitis can be made.²

In Natasha’s case, the specific IgE test results show that she is polysensitised, with sensitisations to house dust mite (HDM), Timothy grass, silver birch, and Alternaria alternata. She has very high levels of HDM-specific IgE, but perhaps surprisingly, given her clinical history, her results indicate that she is not sensitised to cat dander. Therefore, it is likely that her asthma attack during the sleepover with her friend was due to HDM rather than the cat—a point which would have been very difficult to ascertain from her history alone. 

Natasha’s sensitisation to seasonal allergens (Timothy grass, silver birch, and Alternaria alternata) may be the reason for her worsening nasal symptoms and breathlessness over the summer months, as her total allergen load will be increased compared with winter months.⁷

Interpreting these results in conjunction with Natasha’s clinical history and physical examination findings, allowed the GP to confirm a diagnosis of IgE-mediated allergy⁸—in this case, perennial allergic rhinitis (due to HDM) and seasonal allergic rhinitis (due to Timothy grass). 

Management

HDMs are impossible to completely eradicate from a house by cleaning;⁹ however, Natasha could limit her exposure to HDM by using the following strategies: 

• Put dust-proof covers on pillows, mattresses and box springs. Remove and wash the covers frequently^9,10
• Minimize the number of stuffed animals kept in bedrooms or put them in plastic containers⁹
• Remove carpets, drapes and upholstered furniture (as much as possible)¹⁰
• Keep humidity to ≤45 percent¹⁰
• Vacuum carpets twice every week¹⁰

Natasha's peak nasal inspiratory flow is below the normal range determined for adult female patients (~115 mL/min), indicating nasal obstruction.¹¹ Normal adult PEFR range is between 400 and 700 L/min.¹² From her lung function tests, Natasha's low PEFR and FEV1 suggest intrapulmonary airflow obstruction,¹³ which, taken together with her clinical history, is indicative of asthma.¹⁴ Her FeNO is raised, but caution should be exercised when interpreting this result, as the presence of allergic rhinitis can elevate FeNO levels, even in the absence of overt, clinical asthma.²

Did you know?

• Up to 90 percent of allergic patients are polysensitised¹⁵
• Allergic rhinitis confers a 3.5-fold risk for subsequent development of asthma¹⁶ and is a marker of poor asthma control¹⁷

*The following products are included in the ImmunoCAP blood test range:

• ImmunoCAP Allergen d1, House dust mite
• ImmunoCAP Allergen g6, Timothy
• ImmunoCAP Allergen t3, Common silver birch
• ImmunoCAP Allergen e1, Cat dander
• ImmunoCAP Allergen m6, Alternaria alternata

Conclusion

Natasha's journey from persistent symptoms to effective management of her allergic rhinitis demonstrates the transformative power of accurate diagnostic results and personalized care.

BID: twice a day; FEV₁: forced expiratory volume in 1 second; IgE: immunoglobulin E; kU_A/L: allergen-specific kilo units per litre

The people, places and events depicted in these case studies and photographs do not represent actual patients, nor are they affiliated with Thermo Fisher Scientific.