Diagnostic value of the nasal provocation test with Dermatophagoides pteronyssinus in childhood asthma

Usefulness of House Dust Mite Nasal Provocation Test in Asthma

Purpose

We previously reported that the skin prick test was sensitive and the serum specific immunoglobulin E test was specific for predicting positive airway responses to house dust mites (HDMs) in patients with asthma. Because the nose and bronchus are one airway, the nasal provocation test would be more specific for predicting the bronchial responses to HDM than the skin test.

Methods

The allergy skin prick test and nasal and bronchial provocation tests using HDM (Dermatophagoides farinae) were performed in 41 young men (age, 19–28 years) who wanted military certification for asthma. The nasal responses to HDM was scored according to the severity of rhinorrhea, sneezing, and nose itching.

Results

The prevalence of a positive skin prick test to HDM did not significantly differ between patients with (n=24) and without (n=17) an early airway reaction (EAR; 79.2% vs 70.6%, P=0.534). However, the prevalence of a positive nasal test was significantly higher in the airway responders than in the others (37.5% vs 0%, P=0.005). The concordance of a positive response to the nasal test (κ=0.332, P=0.004) but not to the skin prick test (κ=0.091, P=0.529) was significant with an EAR. The diagnostic sensitivity of the nasal test (37.5%) was lower than that of the skin prick test (79.2%), but the specificity was higher (100% vs 29.4%).

Conclusions

The skin prick test is more sensitive, whereas the nasal test is more specific and accurate, for predicting an EAR to HDM in patients with asthma.

Assessment of allergen-induced respiratory hyperresponsiveness before the prescription of a specific immunotherapy

BACKGROUND

Asymptomatic sensitization is a frequent condition that must be considered before the indication of allergic-specific immunotherapy.

OBJECTIVE

The aim of this study was to appreciate and correlate the local and spirometric changes elicited by the allergen-specific nasal provocation test (NPT) to define practical and feasible guidelines for the allergist/immunologist to demonstrate specific respiratory hyperresponsiveness before the indication of allergic-specific immunotherapy.

METHODS

A total of 172 subjects (children and adults) with a diagnosis of allergic rhinitis were submitted to flow-volume spirometry immediately before and after the NPT performed with Dermatophagoides antigens. The differences between the pre- and postspirometric estimated values of peak expiratory flow rate (PEFdif%), forced expiratory volume in 1 second (FEV1dif%), and forced vital capacity (FVCdif%) were correlated with the results of the nasal provocation test symptom score (NPT-SS).

RESULTS

There were 119 subjects (69%) with NPT-SS > 2. Among these patients who were reactive, the mean NPT-SS was 6.3. The Spearman's correlation between PEFdif% and NPT-SS was r = -0.44 (p = 0.01); the Spearman's correlation between FEV1dif% and NPT-SS was r = -0.22 (p = 0.01), and the Spearman's correlation between FVCdif% and NPT-SS was r = -0.21 (p = 0.04).

CONCLUSION

The combined utilization of the allergen-specific NPT-SS with the spirometry (or PEF meter) is a safe methodology to evaluate allergen-specific nasal and bronchial hyperresponsiveness (which sometimes acts as a bronchial provocation test) in patients with allergic rhinitis and asthma due to hypersensitivity who are candidates for allergen-specific immunotherapy.

[Nasal allergen provocation test, allergic skin tests and serum allergen-specific IgE level in asthmatic children]

INTRODUCTION

The important element in the asthma diagnosis is a confirmation of trigger's asthma symptoms allergens.

AIM

The aim of this study was to evaluate diagnostic value of an allergic skin prick test and serum allergen-specific IgE level with reference to nasal allergen provocation test (NPT) results in asthmatic children.

MATERIAL AND METHODS

Study was performed in 80 asthmatic children in 3-14 yrs aged. 118 NPTs accompanied by assessments of nasal airflow by rhinospirography, were done. In all subjects, allergic skin prick tests with mites and grasses or trees pollen allergens and serum allergen specific IgE levels with the allergen used in NPT were done.

RESULTS

Concordance between SPT and TPN results was shown in 59% cases, most often in group with pollen than mites provocation. SPT's sensitivity and specificity in relation to TPN result was 71% and 53%, respectively. Concordance between asIgE level and TPN results was shown in 76% cases. asIgE results sensitivity and specificity in relation to TPN result was 71% and 82%, respectively.

CONCLUSION

The usefulness of skin prick test results in allergologic diagnosis of asthma is lesser than serum allergen specific IgE determination, especially in patients with house dust mites allergens hypersensitivity. Nasal provocation test (NPT) with suspected allergen should be performed in asthmatic children with a negative or doubtful skin prick test or serum allergen specific IgE level results.

Nasal provocation testing as an international standard for evaluation of allergic and nonallergic rhinitis

Standardized nasal provocation testing (NPT) has been shown to be a safe and very useful tool in the diagnosis of allergic and nonallergic rhinitis. However, in the United States, its use has been mostly limited to scientific investigations, and it has not yet been widely accepted as a standard diagnostic procedure in clinical practice. NPT aims to identify and quantify the clinical relevance of inhalant allergens or occupational irritants. During NPT, nasal respiratory mucosa is exposed to an airborne substance suspected to cause symptoms in the respective individual. Clinical reactions are monitored in a controlled and standardized fashion. Nasal secretions, symptoms such as itching, sneezing and, most importantly, nasal obstruction are assessed as well as ocular, bronchial, cutaneous, and systemic reactions. To achieve objective data on changes in nasal airflow and patency after the challenge, anterior rhinomanometry and acoustic rhinometry have been included in the standard protocol of NPT. By monitoring changes of nasal airflow on one hand and of nasal geometry on the other hand, these methods display nasal function in a graphic way just as speech and pure tone audiometry do for auditory function. Also, by their objective nature, these methods offer a clear and internationally comparable standard. This review outlines a protocol for NPT and discusses practical applications and clinical indications. The use of rhinomanometry and acoustic rhinometry as objective diagnostic tools is emphasized. For the diagnosis of allergic and occupational rhinitis, standardized NPT should be regarded as an international diagnostic standard.

Nasal provocation testing: a review

OBJECTIVE

This review focuses on the uses of nasal provocation testing (NPT) for scientific investigations of the mechanisms of allergic and nonallergic rhinitis. It also describes the use of NPT as a diagnostic tool in clinical practice. The indications, contraindications, advantages, and limitations of different techniques for evaluation of nasal responses are reviewed. The paper familiarizes investigators with particulars of different nasal delivery systems, provocation agents, nasal patency measurements, secretion collection, and nasal lavage techniques.

DATA SOURCES

Relevant publications obtained from a literature review.

STUDY SELECTION

Relevant publications on the topics of NPT, allergic, and nonallergic rhinitis were critically evaluated.

RESULTS AND CONCLUSIONS

To date, NPT has been used primarily as a research tool for the investigation of allergic and nonallergic rhinitis with a wide variety of techniques depending on the specific scientific purposes. NPT will continue to provide useful information about the pathogenesis of airway diseases. Standardized nasal provocation testing has the potential to become a more frequently used clinical test in the diagnosis of allergic and occupational rhinitis and for determination of the appropriate and focused therapy.

Diagnostic value of nasal provocation challenge with allergens in children

A total of 106 children suffering from perennial rhinitis and/or asthma, and all allergic to Dermatophagoides pteronyssinus (DP), underwent nasal provocation challenge (NPC) with DP to determine the best method of diagnosis. Posterior rhinomanometry was uninterpretable in 17 patients and gave negative results in 31. Clinical scores for sneezing and rhinorrhea were more effective but did not diagnose the disorder in 11 children. However, nine of the 11 had significant increases in eosinophil count in the late phase. Clinical scores and cytology were also useful for assessing whether NPC with allergens was positive in children. The feasibility and safety of NPC with DP are high for rhinitic and stable asthmatic patients, but mild reactions may occur during the late phase.