Prevalence and clinical relevance of local allergic rhinitis.

BACKGROUND: Evidence demonstrates the existence of local allergic rhinitis (LAR) in nonatopic patients, although its prevalence in the rhinitis population remains unknown. The aim, therefore, of this study was to evaluate the prevalence, clinical characteristics, and severity of LAR in a Spanish rhinitis population, compared with patients having classical allergic rhinitis (AR) with systemic atopy or nonallergic rhinitis (NAR). METHODS: A group of 452 adult rhinitis patients were randomly selected from a total of 3860 who attended our allergy service over 1 year. A clinical questionnaire, skin prick test (SPT), spirometry, and serum total and specific IgE (sIgE) were evaluated. A nasal allergen provocation test with multiple aeroallergens (NAPT-M), including Dermatophagoides pteronyssinus, pollens, alternaria, and dog epithelia, was performed in patients with negative SPT and serum sIgE. RESULTS: A total of 428 patients completed the study; 24 were excluded because of nasal hyper-reactivity. LAR was diagnosed in 25.7%, AR in 63.1%, and NAR in 11.2%. The LAR and AR patients had a similar clinical profile: a nonsmoking woman with severe, persistent perennial rhinitis frequently associated with conjunctivitis and asthma. More than 36% of LAR patients reported rhinitis onset in childhood. NAPT-M detected aeroallergen polysensitization in 37.3% of the LAR patients. Dermatophagoides pteronyssinus was the main sensitizing aeroallergen in LAR and AR (60% vs 54%, P > 0.05). CONCLUSIONS: Local allergic rhinitis is a prevalent entity in patients evaluated with rhinitis. Persistent and severe symptoms associated with conjunctivitis and/or asthma and polysensitization were likely to be detected in LAR and AR.

Negativization rates of IgE radioimmunoassay and basophil activation test in immediate reactions to penicillins.

BACKGROUND: Skin test sensitivity in patients with immediate allergy to penicillins tends to decrease over time, but no information is available concerning in vitro tests. We analysed the negativization rates of two in vitro methods that determine specific immunoglobulin E (IgE) antibodies, the basophil activation test using flow cytometry (BAT) and the radioallergosorbent test (RAST), in immediate allergic reactions to penicillins. METHODS: Forty-one patients with immediate allergic reactions to amoxicillin were followed up over a 4-year period. BAT and RAST were performed at 6-month intervals. Patients were randomized into groups: Group I, skin tests carried out at regular intervals; Group II, skin tests made only at the beginning of the study. RESULTS: Differences were observed between RAST and BAT (P < 0.01), the latter showing earlier negativization. Considering different haptens, significant differences for the rate of negativization were only found for amoxicillin (P < 0.05). Comparisons between Groups I (n = 10) and II (n = 31) showed a tendency to become negative later in Group I with RAST. CONCLUSIONS: Levels of specific IgE antibodies tended to decrease over time in patients with immediate allergic reactions to amoxicillin. Conversion to negative took longer for the RAST assay, although the differences were only detected with the amoxicillin hapten. Skin testing influenced the rate of negativization of the RAST assay, contributing to maintenance of in vitro sensitivity. Because of the loss of sensitivity over time, the determination of specific IgE antibodies to penicillins in patients with immediate allergic reactions must be done as soon as possible after the reaction.

Skin testing for immediate hypersensitivity to betalactams: comparison between two commercial kits.

INTRODUCTION: Skin testing with major and minor determinants of benzylpenicillin is the recommended standard practice to evaluate subjects with immediate hypersensitivity to betalactams. The withdrawal of these products from the market has set us back to the early days, before the introduction of reagents for in vivo testing. OBJECTIVES: To compare a recently released kit of benzylpenicillin conjugated to poly-l-lysine (PPL) and minor determinants mixture (MDM) with the previously existing kit in a positive control group of subjects sensitized to major and/or minor determinants of benzylpenicillin. METHODS: Skin tests with both kits were made in a group of positive subjects previously diagnosed with immediate hypersensitivity to penicillins and with positive results to PPL and/or MDM and in a negative control group. Radioallergosorbent test (RAST) inhibition assays with a pool of sera and individual samples were carried out to compare the inhibition capacity of PPL and MDM of both kits. RESULTS: Of 22 cases selected from our historical group, 14 were positive: eight to PPL, three to MDM and three to both. These results were equivalent for both kits. RAST inhibition studies showed similar potencies in the inhibition of PPL and MDM. CONCLUSIONS: Both tests show similar results in terms of RAST inhibition assays and skin tests sensitivity and specificity in the groups selected. The new assay can be used for the same purpose and indications as the previous test.