Pressurised metered-dose inhalers (MDIs) versus dry powder inhalers devices (DPIs) to rapid-acting inhaled b2-agonists for asthma in children.

OBJECTIVE: To compare the clinical effectiveness of pressurized metered-dose inhalers (MDIs) with that of dry powder inhalers (DPIs) in delivering short-acting b2-agonists in children with asthma. METHODS: Searches were performed in Medline (1997-March 2002), the Cochrane Library Database and the Embase reference lists of review articles and clinical trials. In addition, the international headquarters of b2-agonist manufacturers were contacted. We performed a review of randomized controlled trials. RESULTS: Ten randomized controlled trials were included. No differences in clinical effectiveness were found between MDIs and PDIs. Two studies reported that fewer adverse events occurred when the Turbuhaler was used. Two long-term studies in children found that children preferred the MDI to the Rotohaler. CONCLUSIONS: 1) In stable asthma, short-acting b2 bronchodilators in standard MDIs are as effective as dry powder inhalers. 2) Pooling of results was limited by the small number of studies and therefore no overall conclusions could be drawn. 3) From the limited data available, we found little or no evidence for an additional clinical benefit of DPI devices over standard MDIs in children with asthma.

Positividad de la prueba del parche con fenitoína en un caso de síndromede Stevens-Johnson / Positive patch test with phenytoin in a case of Stevens-Johnson syndrome

El síndrome de Stevens-Johnson (SJS) o eritema multiforme mayor es una reacción de posible mecanismo inmunológico poco frecuente, con una incidencia media anual estimada de 1-2 casos por millón de habitantes. La fenitoína y otros anticonvulsivantes, tales como fenobarbital y carbamnacepina, se han asociado con casos de SJS. Se describe el caso de una mujer de 40 arios de edad, diagnosticada de un tumor cerebral (oligodendroglloma), que presentó un cuadro clínico compatible con SJS, 48 horcas después de administrarle metamizol magnésico y fenitoína, por vía intravenosa (la paciente había realizado previamente un ciclo de tratamiento con buena tolerancia a dichos fármacos). Se realizaron pruebas cutáncas (1prick test) con los preparados comerciales de fenitoína (50 mg/ml) y metamizol (400 mg/ml), que frieron negativas en ambos casos. Se llevaron a cabo pruebas epicutáneas con los preparados comerciales de los fármacos implicados que resultaron positivas a fenitoína, a las 48 y 96 horas con persistencia de la lesión resultante incluso una semana después, y negativas en el caso del metamizol. La provocación oral hasta alcanzar la dosis terapéutica con metamizol fue tolerada. La provocación con fenitoína no se realizó, por el riesgo de una reacción potencialmente grave. Este caso puede servir como ejemplo de la utilidad de las pruebas epicutáneas para llegas- a identificar al agente causal, en casos de SJS relacionados con la toma de varios medicamentos (AU)

Comparison of the efficacy and safety of two preseasonal regimens of glutaraldehyde modified, tyrosine-adsorbed parietaria pollen extract over a period of three years in monosensitive patients.

The purpose of this study was to evaluate the clinical efficacy over a period of three years (1988-90) of two preseasonal dosage regimens of a Parietaria allergoid (Bencard Tyrosine Parietaria) in patients who were only sensitive to this pollen. Fifty patients were included (14 men and 36 women, age: mean, 28 years; range, 14-47 years). Twenty five patients (group A) were treated each january with the basic course of Bencard Tyrosine Parietaria. This consisted of injecting subcutaneously 0.5 ml from each of three vials, with one week between each injection. A further injection using the vial with the highest dose was given one week later. Each january and february, twenty five patients (group B) were treated with the basic course of Bencard Tyrosine Parietaria, repeating the last dose five times, with one week between each injection. Immunotherapy with a tyrosine-adsorbed Parietaria judaica allergoid is an effective method for mitigating nasal (p < 0.0001), bronchial (p < 0.005), conjunctival (p < 0.001) and palatal itching symptoms (p < 0.0001) in patients who are sensitive to this pollen. Sensitivity to Parietaria pollen, as verified by skin test and nasal challenge, decreased during immunotherapy (p < 0.001). Histamine release by peripheral blood basophils decreased during the course of the study, falling from 43.5 ng/ml to 12.3 ng/ml in group A and from 42.9 ng/ml to 10.0 ng/ml in group B; during the second and third years, IgG levels were increased one and four months after starting treatment with the extract, while this was not the case after ten months; IgE levels were also increased. Finally, overall tolerance to this immunotherapy product was good in almost all patients.

The role of rhinovirus in allergic airway inflammation.

Epidemiological data demonstrate that viral infections are the most important trigger for acute asthma symptoms in children, and this association persists in many adults with asthma. Studies on volunteers experimentally infected with rhinoviruses (RV) suggest that atopy alone does not predispose to unusually severe symptoms. In contrast, experimental models combining viral infection and allergen exposure have identified potential links between virus-induced and allergen-induced inflammation. While in vitro studies suggest that cytokines may be an important part of this association, their role must be verified by sampling lower airway fluids and tissues in vivo after experimental and/or natural rhinovirus infections. Although it has long been recognized that the common cold is a potent trigger for symptoms of asthma, the mechanisms underlying the association between upper respiratory infection and increased lower airway obstruction remain obscure. The use of experimental infection of volunteers with or without respiratory allergies has enabled direct comparisons of common cold symptoms in these two groups. Furthermore, techniques such as bronchoalveolar lavage and segmental antigen challenge have been used to directly sample lower airway fluids and tissues during acute viral infection.

Antiallergic properties of antihistamines.

Histamine is a major mediator of the allergic reaction, and histamine H1-receptor antagonists have a long history of clinical efficacy in a variety of allergic disorders. The pathogenesis of allergic disease is complex, involving not only histamine and mast cell-derived tryptase, but also eosinophil and neutrophil derived mediators, cytokines, and intercellular adhesion molecules (ICAM-1). A number of "in vitro" and "in vivo" studies have been performed to assess the clinical effectiveness of antihistamines in inhibiting the allergen-induced inflammatory process in the skin and mucosa. In vitro human studies have shown that high concentration of second generation antihistamines can block inflammatory mediator release from basophils and mast cells, and reduce ICAM-1 expression in epithelial cell lines. In vivo studies have also shown an effect on the allergen-induced inflammatory reaction; both oral and intranasal antihistamines cause a reduction in nasal symptoms and inflammatory cell influx. Analysis of secretory fluids and tissues after challenge indicates that antihistamines interfere with mediator release. Recruitment of inflammatory cells to the site of the allergic insult is also disturbed by antihistamines of second-generation, suggesting that these drugs may inhibit upregulation of molecules involved in cell adhesion and migration, and perhaps they may interfere with the cytokine cascade through their ability of stabilizing mast cells and of limiting the incursion of inflammatory cells. This article reviews available human data on the antiallergic effects of antihistamines.

[Treatment of asthma using aerosols]. / Tratamiento del asma con aerosoles.

The vast majority of clinicians in Europe now prescribe beta-2 agonists as first-line therapy for patients with asthma. Inhaler devices may deliver rapidly acting (beta-2 sympathomimetics) and more slowly acting (anticholinergic) bronchodilator therapy as well as prophylactic medication (sodium cromoglycate and topical corticosteroids). The metered dose inhaler (MDI) is most often prescribed, but at least 50% of patients cannot use this device efficiently and 10-15% of those who can, develop an inefficient technique. The vast majority of those patients are able to use a single-dose dry power inhaler. Recent studies have shown that a multidose dry power system can be used by most patients and is preferred to the MDI by over two-thirds of patient. The large volume spacer systems have been shown to be as good as the MDI and nebulizer systems in the management of asthma, and they are easier to use than the MDI. Nebulisers are of value in chronic asthma in children who cannot use other delivery systems. The role of nebulisers for the domiciliary treatment of asthma in adults, however, remains controversial.

[Non-sedative antihistaminics in the treatment of chronic urticaria]. / Los antihistamínicos no sedantes en el tratamiento de la urticaria crónica.

Antihistamines are the drugs of choice in the symptomatic relief of chronic idiopathic urticaria; however, the usefulness of classic antihistamines has been limited by side effects. In the 1980s a new class of antihistamines has been developed that maintains effectiveness and produces less side effects (eg anticholinergic side effects, daytime sedation, etc). This review analyzes each of the new nonsedating antihistamines commercially available in Spain (astemizole, ebastine, cetirizine, loratadine and terfenadine) and evaluates its clinical efficacy and safety in the treatment of chronic idiopathic urticaria.

[Incidence of adverse reactions to additives. Our experience over 10 years]. / Incidencias de reacciones adversas con aditivos. Nuestra experiencia de 10 años.

No published information exists about the incidence of food additives reactions in the general population. Most studies have been made in patients with urticaria and bronchial asthma. The majority of them lack an adequate design and, therefore, the reported results should be interpreted with extreme caution. In this article, we expose our ten years experience in this field. We have added up 1941 oral provocation tests, with an ample battery of additives, administering the tested substances directly or in aqueous or acid solution (1110 in patients with urticaria, mainly chronic urticaria, and 831 in asthmatic subjects, with or without aspirin intolerance). From these exhaustive data, we get the following conclusions: 1) in contrast with other-investigators, and using similar or even higher provocation doses, we get a very low incidence of adverse reactions. 2) We are sceptical that food additives play any role in chronic urticaria or in other cutaneous processes (only 0.63% provocation tests resulted in an urticarial exacerbation, and none of them was repeated after re-provocation). 3) In asthmatic patients, similar results were obtained, except with sulfites in acid solution challenge test (10% asthmatic exacerbations), possibly as a sign of nonspecific bronchial hyperreactivity. 4) The prescription of food additives free restrictive diets does not seem to be justified. The should be followed only by those patients with clear evidence of additives reactions. 5) In most cases, with punctual exceptions, the study of food additives reactions, in clinical allergy, implies a waste of time.

Determination of eosinophil rate after nasal provocation test in allergic rhinitis diagnosis.

After nasal provocation test in patients with allergic rhinitis, using the allergen they were sensitized to, we have observed: 1) an increase in the percentage of nasal eosinophils after 2, 3, 24 and 48 hours; 2) sneezes, mainly in the first 30 minutes; 3) nasal obstruction in the first three hours; 4) absence of rhinorrhea, but not in all the patients; and 5) no predominance of nasal, auricular and/or palatine pruritus at any time. When patients without rhinitis, or with allergic rhinitis were stimulated using a pneumoallergen they were not sensitized to, no significative increase in the nasal eosinophils percentage was found. No symptoms were observed either. So, we can conclude that nasal secretion samples, for eosinophilia percentage determination, should be taken from 2 to 48 hours after nasal provocation, and that the most frequent symptoms, which are probably related to cellular changes, are nasal obstruction and sneezes.