A Case of Recurrent Urticaria Due to Formaldehyde Release from Root-Canal Disinfectant

Although formaldehyde is well known to cause type 4 hypersensitivity, immunoglobulin E (IgE)-mediated hypersensitivity to formaldehyde is rare. Here, we report a case of recurrent generalized urticaria after endodontic treatment using a para-formaldehyde (PFA)-containing root canal sealant and present a review of previous studies describing cases of immediate hypersensitivity reactions to formaldehyde. A 50-year-old man visited our allergy clinic for recurrent generalized urticaria several hours after endodontic treatment. Prick tests to latex, lidocaine, and formaldehyde showed negative reactions. However, swelling and redness at the prick site continued for several days. The level of formaldehyde-specific IgE was high (class 4). Thus, the patient was deemed to have experienced an IgE-mediated hypersensitivity reaction caused by the PFA used in the root canal disinfectant. Accordingly, we suggest that physicians should pay attention to type I hypersensitivity reactions to root canal disinfectants, even if the symptoms occur several hours after exposure.

Immunologic Evaluation of Immediate Hypersensitivity to Cefaclor

PURPOSE: Cefaclor is widely prescribed for various infectious diseases. As its consumption increases, the number of hypersensitivity reactions to cefaclor has increased. This study aimed to evaluate the immunologic findings of immediate hypersensitivity to cefaclor. MATERIALS AND METHODS: We enrolled 47 patients with immediate hypersensitivity to cefaclor from Ajou University Hospital and Asan Medical Center. Serum specific IgE, IgG1, and IgG4 antibodies to cefaclor-human serum albumin (HSA) conjugate were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The most common phenotype was anaphylaxis (Group I, 78.7%), followed by urticaria (Group II, 21.3%). The detection of specific IgE, IgG1, and IgG4 to cefaclor-HSA conjugate by ELISA tended to be higher in Group I (40.5%, 41.7%, 21.6%) than in Group II (20.0%, 20.0%, 0%) with no statistical significance. Significant associations were found between specific IgE and IgG1 or IgG4 (p<0.001, p=0.019). ELISA inhibition tests showed significant inhibitions by both free cefaclor and cefaclor-HSA conjugate. For basophil activation tests in patients having no specific IgE antibody, the CD63 expression level on basophils increased with incubations of free cefaclor. CONCLUSION: The most common manifestation of immediate hypersensitivity to cefaclor was anaphylaxis, most of which was mediated by IgE; however, a non-IgE mediated direct basophil activation mechanism was suggested in a subset of anaphylaxis patients.

Chlorhexidine urticaria: A rare occurrence with a common mouthwash.

Chlorhexidine is a widely used antiseptic and disinfectant in medical and nonmedical environments. Compared to its ubiquitous use, allergic contact dermatitis from chlorhexidine has rarely been reported and so its sensitization rate seems to be low. The prevalence of contact urticaria and anaphylaxis due to chlorhexidine remains to be unknown. This case report presents a case of urticaria due to oral use of chlorhexidine. The adverse reaction was confirmed by skin prick test.

Allergy to beta-lactams in pediatrics: a practical approach

OBJETIVO: Apresentar uma abordagem prática ao diagnóstico e conduta na alergia a antibióticos beta-lactâmicos. FONTES DOS DADOS: Periódicos da área de alergia indexados nas bases MEDLINE e LILACS, além de estudos e textos clássicos que tratam do tema. SíNTESE DOS DADOS: A alergia à penicilina é relatada com freqüência, em muitos casos resultando na exclusão desse medicamento do arsenal terapêutico. Cerca de 10 por cento dos relatos de alergia a drogas são confirmados. As manifestações clínicas decorrentes da reação alérgica à penicilina são bastante amplas, destacando-se os quadros cutâneos. Os quatro mecanismos de hipersensibilidade de Gell & Coombs estão envolvidos nas reações alérgicas. A penicilina é degradada em determinante maior (95 por cento dos produtos) e em determinantes menores (5 por cento dos produtos). As reações imediatas, mediadas por IgE, e que determinam quadros de anafilaxia, estão relacionadas aos determinantes menores em 95 por cento dos casos. A hipersensibilidade a esses produtos pode ser avaliada através de testes cutâneos realizados com os determinantes maior e menores, permitindo, assim, evitar o choque anafilático em indivíduos alérgicos. O texto ressalta conhecimentos básicos sobre a alergia à penicilina, propiciando um diagnóstico mais adequado desse evento e a conduta em casos de suspeita de alergia a beta-lactâmicos. CONCLUSÃO: O diagnóstico de alergia à penicilina tem sido feito de forma inadequada, resultando em sua exclusão do arsenal terapêutico. O melhor reconhecimento dessas condições permitirá o uso da penicilina com diminuição dos riscos decorrentes da hipersensibilidade.

OBJECTIVE: To present a practical approach to the diagnosis and management of allergy to beta-lactam antibiotics. SOURCES: Allergy journals indexed in MEDLINE and LILACS, as well as seminal studies and texts. SUMMARY OF THE FINDINGS: Allergy to penicillin is commonly reported. In many cases, this results in the decision not to use this drug. About 10 percent of drug allergy reports are confirmed. The clinical manifestations due to allergic reaction to penicillin vary widely, with emphasis on skin disorders. Gell & Coombs' four hypersensitivity mechanisms are involved in allergic reactions. Penicillin is degraded to a major (95 percent) and minor determinants (5 percent). Immediate IgE-mediated reactions causing anaphylaxis are associated with minor determinants in 95 percent of the cases. Hypersensitivity to these products can be assessed using cutaneous tests performed with major and minor determinants, thus avoiding anaphylactic shock in allergic individuals. The present article underscores the basic body of knowledge on allergy to penicillin, providing support for a more accurate diagnosis of this event and for the choice of management in cases of suspected beta-lactam allergy. CONCLUSIONS: The incorrect diagnosis of penicillin allergy frequently leads to the exclusion of this drug as a therapeutic option. A better recognition of these situations will enable the use of penicillin and reduce the risks associated with hypersensitivity.

Study of histamine wheal suppression by dexamethasone with and without iontophoresis.

BACKGROUND: Iontophoresis increases the penetration of drugs into the skin by electric current. The ability of topical steroids to reduce the size of the histamine wheal was used to assess the efficacy of topical dexamethasone delivered with and without iontophoresis. AIM: To determine the wheal suppressing ability of dexamethasone delivered with and without iontophoresis. METHODS: A template with three squares of 3x3 cm was placed on both forearms of 20 volunteers and the edges marked. A gauze piece soaked in 2 ml of dexamethasone solution was placed on the flexor aspect of the left forearm and the electrode, an aluminum foil was placed on it and connected to the negative pole (since dexamethasone is negatively charged). An electric current was passed for 15 minutes. Similarly, on the right forearm, a dexamethasone soaked gauze piece was placed without iontophoresis. Histamine wheal suppression was assessed at the end of 30 min, 1 hr and 2 hrs, on both sides. Statistical analysis was done using an independent t-test. RESULTS: There was a statistically significant difference in wheal suppression at 30 min (p=0.006) on the left hand where iontophoresis was used. CONCLUSION: Our experiment showed that topical dexamethasone with iontophoresis has the maximum effect at the end of 30 minutes and is more effective than dexamethasone without iontophoresis.

Evaluation of antiallergic activity (type I hypersensitivity) of Inula racemosa in rats.

Alcoholic extract of root of Inula racemosa, was studied for its antiallergic effect in experimental models of type I hypersensitivity, viz. egg albumin induced passive cutaneous anaphylaxis (PCA) and mast cell degranulation in albino rats. The alcoholic extract was prepared by the process of continuous heat extraction. LD50 of this extract was found to be 2100 +/- 60 mg/kg, i.p. Assessment of protection against egg albumin induced passive cutaneous anaphylaxix by different doses of Inula racemosa was done by giving drug intraperitoneally or orally for seven days or once only. Mast cell degranulation studies were done by using compound 48/80 as degranulation agent with same dosage schedule. Inula racemosa (i.p. as well as p.o.) showed significant protection against egg albumin induced PCA. Protection against compound 48/80 induced mast cell degranulation by alcoholic extract of Inula racemosa (single dose) was similar to that of disodium cromoglycate. The seven days drug treatment schedule showed greater protection than disodium cromoglycate intraperitoneally. The results suggest that Inula racemosa possesses potent antiallergic properties in rats.

Reacciones a medios de contraste yodados sin muertes. Experiencia durante 29 años / Yodate contrast media reactions. Experience of 29 years

Durante 29 años se estudiaron 178, 439 casos de pacientes expuestos a medios de contraste yodado (MCY) correspondiendo 137,147 a pacientes para urografía excretora y 41,292 a colangiografía. Se realizó un interrogatorio directo insistiendo en los antecedentes personales de alergia a medios de contraste, uso de productos yodados, enfermedades del sistema nervioso y cardiovascular. Se aplicó la prueba cutánea de medios de contraste yodado. Si el resultado fue positivo no se efectuó estudio alguno con medios de contraste yodado o se hizo con medidas especiales. Se encontraron medicamentos preventivos cuando hubo antecedentes de urticaria, asma o angioedema con prueba cutánea negativa. No se registraron casos de muerte

Avaliaçäo da sensibilidade imediata a aeroalérgenos em alunos de graduaçäo do curso de medicina / Evaluation of imdediate hypersensitivity to aeroallergens in medical students

Objectivo: Avaliar a prevalência de sensibilizaçao a aeroalérgenos em estudantes de graduaçao em Medicina. Métodos: Foram selecionados 21 internos do Hospital de Clínicas da UNICAMP - Campinas/SP. Os indivíduos compreenderam dois grupos distintos, sendo o Grupo Controle (GC) formado por nove alunos sem história familiar ou pessoal de atopia e a Grupo Estudado (GE) formado por 12 alunos atópicos com rinite alérgica e/ou asma brônquica. Os dois grupos foram submetidos a teste cutâneo de sensibilidade imediata por puntura (PT) e à dosagem de IgE sérica específica para os aeroalérgenos pela técnica do RAST (Radioallergosorbent test). Resultados: Os resultados demonstraram uma incidência de positividade significativamente aumentada no GE para o extrato de poeira domiciliar (PT) com p<0,03) e para o ácaro Dermatophagoides pteronyssinus (RAST com p<0,03). Quando comparados a estudos anteriores com pacientes atópicos da regiao de Campinas-SP, observou-se menor sensibilizaçao ao ácaro de estocagem Blomia tropicalis, tanto para resultados obtidos com o PT (p<0,01), como com o RAST (p<0,05). Conclusoes: Nossos resultados demonstram sensibilizaçao diferenciada da populaçao de atópicos da regiao de Campinas - SP.

Angioedema neurótico: reporte de un caso clínico / Neurotic angioedema: report of a case

Las reacciones alérgicas abarcan manifestaciones clínicas variadas, que pueden ir de leve (como la que describiremos en este artículo), reacciones retardadas que pueden ocurrir hasta 48 horas después de la exposición al alergeno; hasta las reacciones inmediatas de hipersensibilidad - anafilaxis, las cuales se desarrollan en segundos y ponen en peligro la vida del paciente. Aunque el angioedema es una ocurrencia poco común en el consultorio dental, puede convertirse en una situación embarazosa para el odontólogo. El artículo tiene por finalidad presentar un caso clínico de angioedema neurótico de labio superior, su manejo y los aspectos que deben ser considerados para evitar dichas reacciones. Igualmente, el artículo pretende motivar a los odontólogos a reforzar los conocimientos en el manejo de urgencias médicas

Reações de hipersensibilidade imediatas apos uso intravenoso de soros antivenenos: valor prognostico dos testes de sensibilidade intradermicos / Immediate hypersensitivity reactions after intravenous use of antivenin sera: prognostic value of intradermal sensitivity tests

Foram admitidos no Hospital das Clinicas da FMRPUSP, durante os anos de 1983 a 1988, 494 pacientes vitimas de acidentes ofidicos e escorpionicos que receberam soro antiveneno (SAV) e nos quais foi avaliada a frequencia e tipo das manifestacoes imediatas, bem como o valor prognostico do teste de sensibilidade. Do total de pacientes vitimas de ofidismo, 82 (25,6 por cento) apresentaram reacoes imediatas, das quais as mais comuns foram as cutaneas, isoladas (40 por cento) ou associadas com sintomas respiratorios (19 por cento), seguidas de manifestacoes gastrintestinais (17 por cento). Choque anafilatico foi detectado em 10 pacientes (12 por cento). Em relacao aos acidentes escorpionicos, reacoes imediatas foram observadas em 13 pacientes (7,5 por cento), tambem com predominio de lesoes cutaneas. Sintomatologia cardiocirculatoria foi detectada em apenas 1 paciente. Devido ao baixo valor preditivo positivo (31,8 por cento) e a baixa sensibilidade (54,6 por cento), propomos que o teste de sesibilidade intradermico seja abolido da rotina de atendimento de urgencia aos pacientes vitimas de acidentes por animais peconhentos. Anti-histaminicos (bloqueadores dos receptores "H IND. 1" e "H IND. 2") e corticosteroides devem ser administrados por via parenteral anteriormente a soroterapia, no sentido de prevenir...