RESUMO
The reactions to mosquito bites are immunological reactions with involvement of IgE, IgG and T cells mediated hypersensitivity. These reactions are common and range from small local reactions, large local reactions to systemic allergic reactions. Skeeter syndrome is defined as a large local induced inflammatory reaction to mosquito bite and sometimes accompanied by systemic symptoms such as fever and vomiting. Diagnosis is based on clinical history and physical examination, supported by the identification of specific IgE by skin testing. Treatment includes prevention, antihistamines and steroids in some cases. Specific immunotherapy still requires further study. This paper reports two cases of patients with hypersensitivity reactions to mosquito bites, which were evaluated in our center presenting positive skin tests.
Las reacciones por picaduras de mosquito son reacciones inmunológicas con afectación de la hipersensibilidad mediada por IgE, IgG y linfocitos T. Éstas son frecuentes y van desde reacciones locales pequeñas o grandes, hasta reacciones alérgicas sistémicas. El síndrome de Skeeter es una reacción inflamatoria local grande inducida por la picadura de mosquito, en ocasiones acompañada de síntomas sistémicos como fiebre y vómito. El diagnóstico se basa en la historia clínica y la exploración física, con el apoyo de la identificación de IgE específica mediante pruebas cutáneas. El tratamiento consiste en la prevención de picaduras, administración de antihistamínicos y, en algunos casos, de esteroides. La inmunoterapia específica aún requiere mayor estudio. Comunicamos dos casos de pacientes que manifestaron reacciones de hipersensibilidad a la picadura de mosquito, que fueron evaluados en nuestro centro con pruebas cutáneas positivas.
RESUMO
BACKGROUND: Patients who receive allergen immunotherapy (IT) have a potential risk of systemic reactions, however such reactions are rare when IT administered properly. The frequency of systemic reactions (SR) due to conventional IT is less than 1%. OBJECTIVE: To determine the frequency of secondary SR to allergen IT, and to identify the possible factors involved in developing them. METHODS: A retrospective descriptive study that included 2.319 patients who received 14.600 allergen immunotherapy injections during the period from May 1, 2001 to April 30, 2002. RESULTS: Twelve patients had a SR (age 7 - 40 years), all of which occurred within the first 30 minutes after the IT. These were more frequent during the dose - increase phase (58%). The frequency of (RS) in relation to the number of injections was 1:1216, and regarding to the number of patients, 1:193. The clinical manifestations included bronchospasm 83%, urticaria 67%, gastrointestinal symptoms and hypotension 8.3%. The 58% had anaphylaxis and pulmonary or dermatological symptoms only in 33% and 8.3% respectively. The possible factors involved in the onset of SR were: sensitivity identified by large skin reactions in skin test (PC) 83%, uncontrolled asthma 50%, application of allergens IT during high pollination season 42%, inadequate immunotherapy scheme monitoring 17%. CONCLUSIONS: The frequency of SR in this group of patients was low as that reported in other publications.