Incidence of food anaphylaxis in Piemonte region (Italy): data from registry of Center for Severe Allergic Reactions.

There are wide differences in estimated incidence and prevalence of anaphylaxis because of the absence, until recently, of a universal consensus on the definition of anaphylaxis and the different source of collected data. We aimed to estimate the incidence of food anaphylaxis based on the database of Piemonte Region (Italy) Reference Center for Severe Allergic Reactions. All cases of severe food allergic reactions reported in 2010 were studied. Clinical data associated to the reports were evaluated according to National Institute of Allergy and Infectious Disease and Food Allergy and Anaphylaxis Network diagnostic criteria of anaphylaxis. 75 % of the 778 cases were classified as food anaphylaxis (incidence of 13/100,000 person-years, ranging from 9.9 in adults to 29/100,000 person-years in children). Nuts were the most frequent foods causing anaphylaxis. Milk and eggs were responsible for anaphylaxis more often in children, while peach, vegetables and crustaceans were in adults. Cardiovascular symptoms were more frequent in adults. Gastrointestinal involvement was more frequent in children. A high prevalence of respiratory allergic comorbidities was observed. Food is an important cause of anaphylaxis, particularly in subjects with respiratory allergic comorbidities. Children and adults differ in triggers and clinical presentation of anaphylaxis.

Effect of arterial hypertension on chronic urticaria duration.

BACKGROUND: Reliable clinical or laboratory markers of chronic idiopathic urticaria (CIU) duration are not available. Angioedema, autologous serum skin test (ASST) results, and antithyroid antibodies have been inconsistently associated with longer urticaria duration. OBJECTIVE: To investigate the association of clinical and laboratory parameters with CIU duration, including systemic hypertension, because activation of the coagulation cascade pathway may contribute to the pathogenesis of CIU. METHODS: We performed a prospective study of a cohort of 228 consecutive adult patients with CIU of moderate to severe intensity referred to 2 outpatient allergy clinics and followed up for a 3- to 5-year period. The association of clinical and laboratory parameters (sex, atopy, markers of autoimmunity, antithyroid antibodies, positive ASST result, Helicobacter pylori infection, and hypertension) with urticaria duration was analyzed using semiparametric multivariable proportional hazards models (Cox regression) using remission as main outcome measure. RESULTS: Apart from systemic hypertension (hazard ratio, 0.71; 95% confidence interval, 0.53-0.95; P = .02), none of the considered parameters influenced CIU remission of our patients; 74% and 54% of our patients with and without hypertension, respectively, still had CIU after 5 years. CONCLUSIONS: Our results show, for the first time to our knowledge, that hypertension is associated with extended duration of CIU. This observation, together with the previous findings that point to vascular and coagulation involvement in CIU, may suggest a new approach to antihistamine-refractory CIU treatment, including adequate treatment of hypertension.

Nasal nitric oxide concentration in suspected chronic rhinosinusitis.

BACKGROUND: The role that nasal nitric oxide (nNO) plays in sinonasal diseases is increasingly appreciated. OBJECTIVE: To test the diagnostic value of measuring nNO levels in a symptomatic population undergoing evaluation for potential chronic rhinosinusitis (CRS). METHODS: Of the patients referred to an outpatient allergy clinic for persistent nasal symptoms, those reporting nasal blockage plus 1 or more additional symptoms (discolored discharge, anterior or postnasal drip, facial pain or pressure, and reduction or loss of smell) were categorized as having CRS according to sinus computed tomography scores, with (CRSwNP) and without (CRSsNP) nasal polyps on the basis of endoscopic signs. All the included patients underwent nNO measurement and skin prick tests for common inhalant allergens. Healthy individuals served as controls for nNO measurement. RESULTS: Levels of nNO were significantly lower in patients with CRSwNP (median, 340 ppb; 25th-75th percentile, 145-390 ppb) compared with patients with CRSsNP (762 ppb; 620-1,013 ppb), patients without CRS (917 ppb; 647-1,159 ppb), and controls (843 ppb; 762-962 ppb) (P < .001). Low values of nNO separated very well patients with CRSwNP, and the nNO cutoff value of less than 442 ppb was associated with the best combination of specificity (91%) and sensitivity (87%), resulting in a negative predictive value of 91% and a positive predictive value of 87%. A significant inverse relationship was observed between nNO level and sinus computed tomography score (r2 = -0.39, P < .001). CONCLUSION: Testing for nNO is highly predictive of CRSwNP in a selected population of patients with symptoms suggestive of CRS.

Diagnostic classification of persistent rhinitis and its relationship to exhaled nitric oxide and asthma: a clinical study of a consecutive series of patients.

BACKGROUND: Rhinitis and asthma represent the manifestation of one syndrome. Our hypothesis is that in patients with symptoms of persistent rhinitis, lower airway inflammation, lower respiratory symptoms, and lung function abnormalities compatible with asthma are more frequently associated with the diagnosis of allergic rhinitis (AR) and chronic rhinosinusitis (CRS) than with nonallergic rhinitis (NAR). METHODS: One hundred eight of 590 consecutive patients referred in 1 year for rhinitis were enrolled on the basis of nasal symptoms lasting > 4 weeks. Asthma was diagnosed on the basis of symptoms and a positive bronchodilation testing result and/or methacholine hyperresponsiveness. Exhaled nitric oxide (Feno) was measured with the single exhalation method at 50 mL/s. RESULTS: AR was diagnosed in 39%, NAR in 21%, and CRS in 40%. The prevalence of asthma was significantly higher in AR patients (33%) and CRS patients (42%) than in NAR patients (8.7%) [p = 0.036 and p = 0.005, respectively]. Feno was significantly higher in patients with AR and CRS compared to patients with NAR (44.3 parts per billion [ppb]; 95% confidence interval [CI], 34 to 54 ppb; and 53 ppb; 95% CI, 42 to 64 ppb; vs 22 ppb; 95% CI, 18 to 27 ppb; p = 0.002 and p = 0.001, respectively). Patients with asthma had Feno values significantly higher than patients without asthma (64 ppb; 95% CI, 51 to 77 ppb; vs 33.3 ppb; 95% CI, 28 to 39 ppb; p < 0.001). CONCLUSIONS: The diagnostic classification of persistent rhinitis helps to predict lower airway inflammation (increased Feno) and prevalence of asthma: AR and CRS are associated with higher mean Feno values and higher prevalence of asthma than NAR.

Exhaled nitric oxide in persistent rhinitis with or without lower airway involvement: a review of the literature.

The link between upper and lower respiratory airways has been investigated in the past decade leading to the concept of united airways disease. This hypothesis was suggested by several epidemiological observations, which had shown the high prevalence of rhinitis and sinusitis in patients with asthma, and indirectly, by observing the effects of drugs used for rhinitis on asthma symptoms. A broad spectrum of airway involvement severity can be associated with rhinitis or rhinosinusitis: from a subclinical/asymptomatic inflammatory involvement with an increase in eosinophils in induced sputum cell count, to asthma-like symptoms without functional features of asthma with or without extrathoracic airway hyperresponsiveness, to respiratory symptoms with clinical and functional criteria of asthma. The aim of this paper is to review the literature about the role of breath analysis in the relationship between nose and lung, focusing on exhaled nitric oxide (FE(NO)) measurement, a non-invasive marker of inflammation, in rhinitis and in chronic rhinosinusitis in patients complaining or not of asthma symptoms.

Level of exhaled nitric oxide during human anaphylaxis.

BACKGROUND: Nitric oxide (NO) seems to play an important pathophysiologic role in modulating the systemic changes associated with anaphylaxis. Even if some effects of NO may be protective, animal models of anaphylaxis have shown that the summation effects of NO are deleterious, resulting in hypotension and loss of intravascular volume. There are no studies of NO production during anaphylaxis in humans. OBJECTIVE: To measure the level of exhaled NO during anaphylaxis induced by bee venom cluster immunotherapy in a 34-year-old beekeeper. METHODS: Exhaled NO was measured using a chemiluminescence analyzer at different flow rates, and alveolar NO concentration and airway NO production were calculated. RESULTS: We measured a high level of exhaled NO (78 ppb at 50 mL/s, with increased alveolar concentration and airway production) during anaphylaxis induced by bee venom immunotherapy in this patient. Normal values of exhaled NO were measured in the same patient 1 week later before and after a modified regimen of desensitization. CONCLUSIONS: Nitric oxide production was increased in the respiratory tract during anaphylaxis. Having excluded all the common causes of increased exhaled NO levels, these resultssupport the hypothesis that NO plays an important role in anaphylaxis.

Exhaled nitric oxide as a diagnostic test for asthma in rhinitic patients with asthmatic symptoms.

BACKGROUND: Rhinitis is a major risk factor for asthma, so that evaluation of the lower airways is recommended in patients with rhinitis. Exhaled nitric oxide (FE(NO)) is considered a marker of airway inflammation and it has been found to be useful for the screening of patients with suspected diagnosis of asthma. Our aim was to assess the validity and accuracy of FE(NO) to identify patients with asthma in 48 non-smoking patients with persistent rhinitis and asthma-like symptoms. METHODS: Asthma was diagnosed on the basis of 12% improvement in FEV1 after salbutamol or a methocholine PD(20)FEV1<800 microg. Prior to lung function FE(NO) was measured with the single exhalation method at 50 ml/s. RESULTS: The geometric mean (95% confidence interval) FE(NO) was significantly higher in the 18/48 asthmatics than in the non-asthmatic patients (60 ppb, CI 95%: 50-89, versus 30 ppb, CI 95%: 28-45, P=0.001). Receiver operating characteristic (ROC) curve for the diagnosis of asthma indicated that FE(NO) is an acceptable discriminator between patients with and without asthma (area under the ROC curve=0.78). None of the asthmatic patients had FE(NO) values<25 ppb and all the patients with FE(NO)>100 ppb (n=5) were asthmatics. The sensitivity and specificity of FE(NO) for detecting asthma, using 36 ppb as cut-off point, were 78% and 60% and the positive and negative predictive values were 54% and 82%, respectively. CONCLUSIONS: Measuring FE(NO) may be useful for the screening of rhinitic patients with asthma-like symptoms.

Allergy to pigeon tick (Argas reflexus): demonstration of specific IgE-binding components.

BACKGROUND: The European tick, Argas reflexus, is an urban pest parasitizing urban pigeons and may cause a wide range of allergic reactions. METHODS: Specific IgE to A. reflexus, SDS-PAGE and IgE immunoblotting, performed with tick extract, were carried out in the sera of 6 patients who reported allergic reactions after tick bite. RESULTS: Specific IgE to A. reflexus (RAST class ranging from 1 to 3) were detected in the sera of 6 patients who reported allergic reactions (urticaria and angioedema in 2 and anaphylaxis in the other 4 patients) after tick bite. IgE reactivity to two bands of 22 and 40 kDa were identified in the patient sera. CONCLUSIONS: Allergy to A. reflexus has to be considered in allergic patients living in buildings where pigeons have their nests. The powerful sensitizing property of tick allergen is underlined by the observation that none of our patients was atopic.