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Although urticaria is not a life-threatening disease, its impact on quality of life in children should not be overlooked. A systematic search of online databases, including Medline, was performed to inform a review aiming to equip clinicians with an evidence-based approach to all aspects of pediatric urticaria. This review hinges on an illustrative case and includes a summary table of studies pertaining to disease management in children. The multiple issues faced by patients, their families, and treating clinicians are highlighted, and the current literature on the presentation, natural history, investigation, and management of this poorly understood condition is assessed.

La urticaria es definida por la presencia de habones pruriginosos con o sin angioedema que aparecen en minutos a horas y usualmente se autolimitan en 24 horas. Si el tiempo de duración es mayor de 6 semanas se considera crónica. La urticaria es causada por la degranulación del mastocito atribuido a causas de orden inmunológico, no inmunológico e idiopáticas. Se denomina urticaria crónica idiopática cuando el mecanismo patofisiológico de urticaria persistente no es establecido y se ha demostrado que alrededor del 50 por ciento de estos pacientes presenta anticuerpos liberadores de histamina dirigidos contra el receptor de alta afinidad de Ig E (FceRI) o contra la misma Ig E. De ahí, el concepto de urticaria autoinmune y el enfoque terapéutico inmunosupresor a este subgrupo de urticaria. Se revisará la clasificación y lineas de tratamiento.

La urticaria es una condición heterogénea que puede manifestarse clínicamente de formas muy diversas, cuyo signo más común es el habón o roncha. Existen muchas posibles causas de urticaria, y la gravedad y patrón clínico pueden variar considerablemente de paciente a paciente. Por este motivo el tratamiento debe ser individualizado y debe modificarse caso a caso. Clínicamente consiste en una erupción temporal de zonas eritematosas y edematosas que corresponden a aumentos de volumen de la dermis, generalmente acompañados de prurito. La urticaria es clasificada en aguda y crónica según su duración, considerándose seis semanas como el tiempo máximo para hablar de urticaria aguda, cuando las lesiones están presentes por más de seis semanas, hablamos de urticaria crónica (UC). Existen múltiples factores gatillantes de urticaria, como alimentos, inhalantes, fármacos, infecciones, etc. El tratamiento es complejo y consiste en medidas no farmacológicas (ambientales), las que pueden llevarse a cabo más fácilmente en la medida que se identifiquen los factores gatillantes, y en el uso de fármacos principalmente antagonistas anti H1. En este artículo se discutirá sobre los aspectos generales de la urticaria crónica, los tratamientos que hoy existen y aquellos que se están desarrollando.

OBJECTIVE: To review clinical trial data to determine the benefits of using montelukast alone or as combination therapy in the treatment of urticaria. DATA SOURCES: MEDLINE (1966-March 2006) and International Pharmaceutical Abstracts (1970-October 2005) were searched to find clinical trial publications that addressed the use of montelukast in urticaria. DATA SYNTHESIS: Six clinical trials were identified. Montelukast was compared alone and as combination therapy with nonsedating histamine1-receptor antagonists to determine efficacy and safety. Patients had chronic or physical urticaria. The results were mixed. Some studies demonstrated that montelukast can decrease urticarial symptoms with minimal adverse effects, while others found no differences. CONCLUSION: Large-scale, controlled trials are needed to determine which patients would likely benefit from treatment with montelukast.

Se presentan dos casos portadores de cuadros urticarianos crónicos, con pápulas pruriginosas de más de 24 horas de duración e imagen histopatológica de vasculitis leucocitoclásica, que fueron rotuladas como urticaria vasculítica. Se discute la difícil ubicación nosológica dado que los valores de complemento en sangre fueron normales y no se detectaron enfermedades autoinmunes o neoplasias asociadas

La urticaria crónica es una entidad que se caracteriza por la presencia de ronchas, la mayoría de las veces pruriginosas; los síntomas persisten más de 6 semanas. El diagnóstico etiológico puede demostrarse hasta en un 40% a pesar de una historia clinica y exámenes detallados. En nuestro estudio retrospectivo se incluyeron 161 pacientes que consultaron por urticaria crónica en el servicio de alergia. La etiología más frecuente fue la idiopática (57%) seguida por la urticaria vasculítica (12%). Se observó una alta frecuencia de esta patología en el sexo femenino (76,4%) en comparación con el sexo masculino (23,9%). En cuanto al tratamiento, la gran mayoría de pacientes respondió favorablemente a los antihistamínicos de primera o segunda generación. En cambio, en otros se utilizó terapia combinada con anti-H1 y bloqueantes anti-H2. En un pequeño grupo de pacientes hubo que asociar fármacos como levotiroxina, corticoesteroides, inmunorreguladores, antileucotrienos y gammaglobulina endovenosa.

BACKGROUND: Urticaria is a common skin disease characterised by itching weals or hives, which can occur almost anywhere on the body. There are a number of different subtypes and a range of available treatment options. There is lack of agreement on the efficacy of H2-receptor antagonists used in the treatment of urticaria. OBJECTIVES: To assess the safety and effectiveness of H2-receptor antagonists in the treatment of urticaria. SEARCH METHODS: We searched the following databases up to 7 October 2011: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library (2011, Issue 4), MEDLINE (from 2005), EMBASE (from 2007), and LILACS (from 1982). We also searched online trials registries for ongoing trials. SELECTION CRITERIA: Randomised controlled trials of H2-receptor antagonists in people with a clinical diagnosis of urticaria of any duration or of any subtype. Studies including H1-antihistamines for chronic urticaria are the topic of a separate Cochrane review; thus, they were not included in this review. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted and analysed data. MAIN RESULTS: Four studies of a relatively small size, involving 144 participants, were included in this review. A combination of ranitidine with diphenhydramine was more effective at improving the resolution of urticaria than diphenhydramine administered alone (risk ratio (RR) 1.59, 95% confidence interval (CI) 1.07 to 2.36). Although there was a similar improvement in itching, weal size, and intensity, cimetidine provided no statistically significant greater overall improvement in symptoms of urticaria when compared to diphenhydramine. However, a combination of these medications was more effective than diphenhydramine alone (RR 2.02, 95% CI 1.03 to 3.94). Adverse events were reported with several of the interventions, i.e. ranitidine and diphenhydramine, causing drowsiness and sedation, but there was no significant difference in the level of sedation from baseline with either famotidine or diphenhydramine. AUTHORS' CONCLUSIONS: The very limited evidence provided by this review was based on a few old studies of a relatively small size, which we categorised as having high to unclear risk of bias. Thus, at present, the review does not allow confident decision-making about the use of H2-receptor antagonists for urticaria. Although some of these studies have reported a measure of relief of symptoms of urticaria and rather minimal clinical improvement in some of the participants, the evidence was weak and unreliable. We have emphasised the lack of precision and limitations in the reported data where appropriate in this review.

Resumen: la urticaria crónica espontánea es una enfermedad que produce gran compromiso en la calidad de vida del paciente y de la que aún se desconocen, en gran parte, los mecanismos fisiopatológicos asociados, ya que no son generalizables en todos los individuos. Existen factores intrínsecos y extrínsecos implicados en el desarrollo y persistencia de la enfermedad, los cuales pueden actuar de forma individual o coexistente. En esta revisión se proponen algunos cambios en la clasificación actual de la enfermedad, donde se incluye una subdivisión dentro de la urticaria crónica denominada urticaria crónica mixta, la cual hace referencia a los casos donde coexisten factores intrínsecos y extrínsecos para la aparición de la enfermedad en el mismo individuo. Algunos procesos infecciosos virales, bacterianos y parasitarios se han asociado en el desarrollo o severidad de los síntomas de la urticaria crónica en un subgrupo de pacientes, por lo tanto, son incluidos como factores extrínsecos del individuo dentro de las urticarias crónicas inducibles no físicas. Estas modificaciones son propuestas con el fin de optimizar el diagnóstico y manejo de los pacientes con urticaria crónica mixta. (AU)

BACKGROUND: Chronic spontaneous urticaria (CSU) is characterised by the development of crops of red, itchy, raised weals or hives with no identifiable external cause. OBJECTIVES: To assess the effects of H1-antihistamines for CSU. SEARCH METHODS: We searched the following databases up to June 2014: Cochrane Skin Group Specialised Register, CENTRAL (2014, Issue 5), MEDLINE (from 1946), EMBASE (from 1974) and PsycINFO (from 1806). We searched five trials registers and checked articles for references to relevant randomised controlled trials. SELECTION CRITERIA: We included randomised controlled trials of H1-antihistamines for CSU. Interventions included single therapy or a combination of H1-antihistamines compared with no treatment (placebo) or another active pharmacological compound at any dose. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures as expected by The Cochrane Collaboration. Our primary outcome measures were proportion of participants with complete suppression of urticaria: 'good or excellent' response, 50% or greater improvement in quality of life measures, and adverse events. We present risk ratios (RR) with 95% confidence intervals (CIs). MAIN RESULTS: We identified 73 studies (9759 participants); 34 studies provided data for 23 comparisons. The duration of the intervention was up to two weeks (short-term) or longer than two weeks and up to three months (intermediate-term). Cetirizine 10 mg once daily in the short term and in the intermediate term led to complete suppression of urticaria by more participants than was seen with placebo (RR 2.72, 95% CI 1.51 to 4.91). For this same outcome, comparison of desloratadine versus placebo in the intermediate term (5 mg) (RR 37.00, 95% CI 2.31 to 593.70) and in the short term (20 mg) (RR 15.97, 95% CI 1.04 to 245.04) favoured desloratadine, but no differences were seen between 5 mg and 10 mg for short-term treatment. Levocetirizine 20 mg per day (short-term) was more effective for complete suppression of urticaria compared with placebo (RR 20.87, 95% CI 1.37 to 317.60), and at 5 mg was effective in the intermediate term (RR 52.88, 95% CI 3.31 to 843.81) but not in the short term, nor was 10 mg effective in the short term. Rupatadine at 10 mg and 20 mg in the intermediate term achieved a 'good or excellent response' compared with placebo (RR 1.35, 95% CI 1.03 to 1.77). Loratadine (10 mg) versus placebo (RR 1.86, 95% CI 0.91 to 3.79) and loratadine (10 mg) versus cetirizine (10 mg) (RR 1.05, 95% CI 0.76 to 1.43) over short-term and intermediate-term treatment showed no significant difference for 'good or excellent response' or for complete suppression of urticaria, respectively. Loratadine (10 mg) versus desloratadine (5 mg) (intermediate-term) showed no statistically significant difference for complete suppression of urticaria (RR 0.91, 95% CI 0.78 to 1.06) or for 'good or excellent response' (RR 1.04, 95% CI 0.64 to 1.71). For loratadine (10 mg) versus mizolastine (10 mg) (intermediate-term), no statistically significant difference was seen for complete suppression of urticaria (RR 0.86, 95% CI 0.64 to 1.16) or for 'good or excellent response' (RR 0.88, 95% CI 0.55 to 1.42). Loratadine (10 mg) versus emedastine (2 mg) (intermediate-term) showed no statistically significant difference for complete suppression (RR 1.04, 95% CI 0.78 to 1.39) or for 'good or excellent response' (RR 1.09, 95% CI 0.96 to 1.24); the quality of the evidence was moderate for this comparison. No difference in short-term treatment was noted between loratadine (10 mg) and hydroxyzine (25 mg) in terms of complete suppression (RR 1.00, 95% CI 0.32 to 3.10). When desloratadine (5 to 20 mg) was compared with levocetirizine (5 to 20 mg), levocetirizine appeared to be the more effective (P value < 0.02). In a comparison of fexofenadine versus cetirizine, more participants in the cetirizine group showed complete suppression of urticaria (P value < 0.001). Adverse events leading to withdrawals were not significantly different in the following comparisons: cetirizine versus placebo at 10 mg and 20 mg (RR 3.00, 95% CI 0.68 to 13.22); desloratadine 5 mg versus placebo (RR 1.46, 95% CI 0.42 to 5.10); loratadine 10 mg versus mizolastine 10 mg (RR 0.38, 95% CI 0.04 to 3.60); loratadine 10 mg versus emedastine 2 mg (RR 1.09, 95% CI 0.07 to 17.14); cetirizine 10 mg versus hydroxyzine 25 mg (RR 0.78, 95% CI 0.25 to 2.45); and hydroxyzine 25 mg versus placebo (RR 3.64, 95% CI 0.77 to 17.23), all intermediate term. No difference was seen between loratadine 10 mg versus mizolastine 10 mg in the proportion of participants with at least 50% improvement in quality of life (RR 3.21, 95% CI 0.32 to 32.33). AUTHORS' CONCLUSIONS: Although the results of our review indicate that at standard doses of treatment, several antihistamines are effective when compared with placebo, all results were gathered from a few studies or, in some cases, from single-study estimates. The quality of the evidence was affected by the small number of studies in each comparison and the small sample size for many of the outcomes, prompting us to downgrade the quality of evidence for imprecision (unless stated for each comparison, the quality of the evidence was low). No single H1-antihistamine stands out as most effective. Cetirizine at 10 mg once daily in the short term and in the intermediate term was found to be effective in completely suppressing urticaria. Evidence is limited for desloratadine given at 5 mg once daily in the intermediate term and at 20 mg in the short term. Levocetirizine at 5 mg in the intermediate but not short term was effective for complete suppression. Levocetirizine 20 mg was effective in the short term, but 10 mg was not. No difference in rates of withdrawal due to adverse events was noted between active and placebo groups. Evidence for improvement in quality of life was insufficient.