OBJECTIVE. The purpose of this study was to review the nature of adverse reactions, or “breakthrough reactions,” experienced by patients who received steroid premedication and low-osmolar contrast media. We compared the demographics of patients having these breakthrough reactions with those of patients who did not develop these reactions.MATERIALS AND METHODS. We retrospectively reviewed our radiology quality improvement database to identify patients with breakthrough reactions that occurred from January 1, 1994, through October 1, 1999, and we reviewed their medical records. We compared these patients with a control cohort of patients who had a history of prior adverse reaction to contrast media but no breakthrough reaction after administration of low-osmolar contrast media and premedication with corticosteroids.RESULTS. Over the 6-year period, 52 patients experienced 61 breakthrough reactions. The breakthrough reaction was mild in 76% of the patients. The breakthrough reaction was similar to the patient...

Breakthrough adverse reactions to low-osmolar contrast media after steroid premedication.

Resume Objectif – Le but de cette revue generale a ete de proposer une conduite a tenir diagnostique et de prevention ulterieure chez les patients ayant presente une reaction d’hypersensibilite immediate avec un medicament iode Source des donnees – Recherche dans la banque de donnees PubMed® des articles de langue anglaise et francaise publies de 1967 a 2004 Des references complementaires ont ete ajoutees provenant de la bibliographie des articles selectionnes ou de la base de donnees des auteurs Les mots cles employes separement ou en combinaison etaient : Hypersensitivity, Immediate, Allergy, Contrast Media, Povidone-Iodine, Iodine, Iodine Compounds, Iodides, Amiodarone, Seafood, Parvalbumins, Tropomyosin Selection des travaux – Ont ete selectionnes les etudes randomisees, les etudes epidemiologiques, les articles originaux, les cas cliniques et les lettres a la redaction Synthese des travaux – L’implication de l’iode n’a jamais ete demontree au cours des reactions d’hypersensibilite allergique IgE-mediee avec un medicament iode En revanche, des reactions d’hypersensibilite allergique IgE-mediee ont ete decrites avec les produits de contraste iodes et les antiseptiques iodes qui font l’objet de cette revue generale Par extension, les reactions d’hypersensibilite allergique IgE-mediee aux produits de la mer seront evoquees car souvent indument considerees comme un facteur de risque de reaction aux medicaments iodes La sequence allergenique responsable de la sensibilisation des patients n’est pas connue pour les produits de contraste iodes En revanche, il s’agit probablement pour la polyvinylpyrrolidone iodee de la povidone qui correspond au transporteur d’iode Pour les poissons et pour les crustaces et mollusques, il s’agit respectivement de la proteine M et de la tropomyosine qui sont toutes les deux des proteines musculaires Lors de la survenue d’une reaction d’hypersensibilite immediate avec un medicament iode, un bilan biologique immediat et un bilan cutane a distance s’imposent afin de prouver le mecanisme immunologique, d’identifier le medicament ou la substance en cause et de rechercher une eventuelle reactivite croisee notamment pour les produits de contraste iodes Conclusion – La question sur « l’allergie a l’iode » ne doit plus etre posee au patient parce qu’elle induit une reponse inappropriee de sa part mais egalement une attitude therapeutique non fondee et aleatoire de la part du praticien Seul un diagnostic formel d’allergie medicamenteuse, fonde sur l’histoire clinique, la biologie et les tests cutanes, permet de mettre en place les mesures de prevention adaptees

« Allergie à l’iode » : le point sur la question

Mastocytosis are characterized by an accumulation of abnormal mast cells in various tissues. Their incidence is estimated at 1/150,000 patients. Pure cutaneous mastocytosis which are mainly observed during childhood may resolve spontaneously during adolescence, whereas systemic mastocytosis involving one or more organs or tissues are more observed in adults. The initial event leading to mastocytosis is believed to be related to activating mutations in c-kit receptor, thus resulting in increased proliferation of mast cells precursors, migration in various tissues and degranulation leading to clinical signs. This nosologic entity does not belong to allergic diseases. Their perioperative management involves a multidisciplinary approach. The degranulation of mast cells with subsequent clinical symptoms can be triggered by psychological, chemical, traumatic, physical (rubbing, extreme temperatures...) agents. Avoiding these triggers should be realized whenever possible according to each patient. The premedication has not proven its efficiency. Tryptase measurement is part of the preoperative biological assessment. The clinical signs severity is related to the cardiovascular homeostasis disturbances (arterial hypotension, cardiovascular collapse, cardiac arrest). The cardiovascular symptoms do not correlate to the cutaneous versus systemic description of the disease. The drug of choice for the treatment of the severe cardiovascular signs is epinephrine associated to vascular loading. The aim of this literature review is to suggest the different modalities of perioperative care of patients with mastocytosis.

Mastocytoses et anesthésie

We report a grade III allergic hypersensitivity reaction occurring in a 72-year-old patient immediately after anaesthesia induction. Anaphylaxis to cisatracurium was diagnosed on clinical symptoms, biological tests and positivity of the cutaneous tests to this neuromuscular blocking agent. Five days after this allergological assessment, rocuronium, a muscle relaxant for which skin tests appeared negative was used during surgery without adverse effects. The authors underline the value of a detailed allergological assessment to identify the pathophysiologic mechanism, the culprit drug and to propose a safer alternate drug that might be used.

Intérêt des tests cutanés pour le choix d'un curare après une réaction anaphylactique

SummaryBackground and objectives: To analyse the prevalence of positive prick-tests to all medicaments normally checked in allergy units when a patient is suspected of being allergic to anaesthetics. To establish the degree of agreement between the antecedents of a previous history of an allergic reaction to a medicament and the positive result, or not, to the specific prick-test for the said medicament. Methods: This was a prospective study, during 2003 and 2004, which analysed 473 patients referred by their doctors to allergy units to make retrospective diagnoses of an allergy to a drug. The prick-test was done using the undiluted drug. All patients were tested for 41 drugs. These include antibiotics, trimethoprim–sulphamethoxazole, non-steroidal anti-inflammatory drugs (NSAIDs) and perioperative drugs (PD): neuromuscular blocking drugs, latex, iodine, local anaesthetics, hypnotics, opioids and coadjuvants. Cohen's Kappa Index was used to determine the degree of agreement. Results: 71.5% of patients studied presented a positive prick-test. The largest number of positive cases was found in antibiotics (56.4%), followed by PD (15.6%), NSAIDs (14.4%) and trimethoprim–sulphamethoxazole (12.7%). Among PD, the highest prevalence of positive prick-tests was found for neuromuscular blocking drugs (5.3%). Agreement between the substance suspected of causing the allergic reaction and the positive prick-test was excellent for penicillin (Kappa = 0.74) and other antibiotics (Kappa = 0.721) and good for NSAIDs (Kappa = 0.47) and iodine (Kappa = 0.54). Conclusions: The prevalence of patients with positive prick-tests to PD occurred in 15.6% in this prospective cohort. Neuromuscular blocking drugs were found to have the highest prevalence of positive prick-tests. There is positive agreement when the substance responsible for the allergic reaction is suspected, otherwise agreement is low.

P. Dewachter

Papers

La prévention du risque allergique peut-elle être assurée par une médication préanesthésique ?

La prévention du risque allergique peut-elle être assurée par une médication préanesthésique ?