Usefulness of the Allergen Specific Nasal Provocation Test in the Diagnosis of Shellfish Allergy

Background: Shellfish allergy is an important cause of food allergy and anaphylaxis worldwide. Several allergenic proteins have been described in the last few years, but the only diagnostic tool that allows discrimination between allergic and non-allergic sensitized subjects is still the oral food challenge (OFC). Objective: The aim of this study was to evaluate the usefulness of nasal allergen provocation test (NAPT) as a diagnostic tool in the diagnosis of shellfish allergy. Methods: Forty-five subjects with confirmed sensitization to shrimp by a positive skin prick test (SPT) to a commercial shrimp extract were recruited and classified as Sensitized-Allergic or non-Allergic based on current tolerance to shrimp intake, the result of an OFC with a freeze-dried cooked shrimp mixture extract, or recent history of anaphylaxis from shrimp ingestion. These subjects and ten controls without shrimp sensitization were subjected to a NAPT with a freeze-dried cooked shrimp mixture extract. The response was evaluated by means of acoustic rhinometry (AcRh) and visual analogue scale scores (VAS). Results: Significant differences (p=.001) were found between the Sensitized-Allergic group (18/20 positive NAPT, 90%) compared to both Sensitized-non-Allergic (2/18 positive NAPT, 11.1%) and Control (0/10 positive NAPT) groups. NAPT allows differentiation between allergic and non-allergic subjects with a S: 90%, E: 89%, PPV: 90% and NPV: 89%. Conclusions: According to the study results NAPT may be a useful diagnostic tool that allows differentiating sensitized symptomatic subjects from sensitized tolerant. It could be a valuable test to consider when conducting a shrimp allergy study.

Local allergic rhinitis - a big challenge in clinical practice

Local allergic rhinitis is a new rhinitis phenotype characterized by symptoms similar to allergic rhinitis, in non-atopic patients with a positive nasal allergen provocation test (NAPT). The disease is diagnosed in over 25% of non-atopic patients with rhinitis, marked as non-atopic rhinitis. It most often has perennial and severe symptoms and a progressive course. It is often associated with conjunctivitis and/or asthma. It is necessary to consider local allergic rhinitis in patients with non-atopic rhinitis. The gold standard for diagnosis is positive NAPT. Pharmacological therapy fails to stop the natural progression and development of comorbidities. Allergen immunotherapy reduces the symptoms, consumption of medicines and increases the tolerance to allergens responsible for local allergic rhinitis. New studies are needed to confirm curative and evaluate the preventive effects of allergen immunotherapy.

Possibility of Local Allergic Rhinitis in Japan

Background The concept of local allergic rhinitis (LAR) has been advocated recently. Allergic rhinitis in Japan is characterized by house dust mites (HDMs) and Japanese cedar pollen (JCP). To investigate LAR in Japan, total IgE and antigen-specific IgE (sIgE) were measured in inferior turbinate mucosa and their relationships with skin test (ST) and nasal allergen provocation test (NAPT) and as well as serum IgE levels were examined. Methods Subjects were 50 rhinosinusitis patients for surgery. ST was performed and serum total IgE and sIgE levels were measured preoperatively. Patients with class-0 serum anti-HDM or anti-JCP sIgE levels were subjected to NAPT with HDM or JCP, respectively, or both. In all patients, inferior turbinate mucosa was weighed and mashed, and total IgE and sIgE levels were then measured as local mucosal date per gram and per milligram. Because there is no clinical consensus how to evaluate nasal sIgE yet, both positive NAPT and detectable sIgE in obtained nasal mucosa were adopted as the diagnostic criteria of LAR in order to strictly elucidate the possibility of presence of LAR in Japan. Results JCP LAR was definitely diagnosed in 2 of 14 patients (14.3%) and HDM LAR in 5 of 21 (23.8%) in cases with rhinosinusitis symptoms in the absence of positive ST nor serum sIgE. Conclusion The present results positively support LAR by HDM or JCP being present in Japan.

Prospective comparison of a nonmodified and a modified mite extract for immunotherapy in children and adolescents

Aim: This prospective study compares nonmodified and modified house dust mite extracts for allergen immunotherapy (AIT) in pediatric patients with allergic asthma. Materials & methods: Total 95 patients underwent bronchial allergen provocation (BAP). AIT was recommended to 62 patients. Complete datasets of 54 subjects were obtained. Primary aim was the comparison of treatment success defined by BAP between two extracts after 1 year. Secondary parameters were laboratory parameters and clinical symptoms. Results: Significant improvement (p < 0.001) was measured by BAP in both treatment groups. No change was seen in the controls. Both extracts exerted comparable effects on all parameters. Conclusion: After 1 year of AIT, the extracts were equally efficient, with significant improvements in 70.0% (nonmodified) and 72.2% (modified) of patients.