Anaphylaktoide Reaktionen in der Prähospitalphase

The term anaphylactoid reaction is a generic term used for allergic reactions with symptoms of anaphylaxis. Anaphylaxis is a severe systemic allergic reaction that is potentially fatal. It requires prompt recognition and immediate management. The syndrome can affect virtually any organ in the body, although reactions involving the respiratory, the cardiovascular, the cutaneous and the gastrointestinal systems are most common. Anaphylaxis is caused by the release of mediators from mast cells and basophiles. Reactions typically follow a uniphasic course; however, 20% will be biphasic in nature. The second phase usually occurs after an asymptomatic period of 10 hours in the mean.Adrenaline is the pharmacological treatment of choice and should be used in all patients showing signs of beginning blood pressure decrease or upper airway oedema. Further therapy in the treatment of anaphylaxis includes circulatory support, volume therapy, antihistamines and corticosteroids. Post-treatment observation of these patients is absolutely necessary. Once recovered, patients should be hospitalized and monitored for the following 24-48 hours.     

Anaphylaxis to insect sting associated with urticaria pigmentosa.

Anaphylaxis associated with insect stings has been reported to cause approximately 40 deaths per year in the United States. Immunotherapy with venom extracts is a well-established method of treatment of allergy to insect stings. The duration of therapy is based mainly on the initial symptoms and the presence or absence of systemic symptoms during therapy. Evaluation of immunoglobulin E and immunoglobulin G levels as well as repeat skin tests and sting challenges may also provide some additional benefit but are not as useful as the former two criteria. Patients with mastocytosis have a particularly increased risk for anaphylaxis after insect stings. There are many case reports of individuals first diagnosed with mastocytosis after an episode of anaphylaxis after an insect sting, in addition these patients tend to have more severe reactions as well as repeated episodes of systemic reactions during immunotherapy. Early diagnosis of mastocytosis and proper treatment can contribute greatly to the outcome in patients who present with venom allergy.     

Choc à l’ioxaglate (Hexabrix 320®) lors de coronarographies. À propos de deux cas

Immediate reactions to radio contrast media are rather well documented, but their physiopathological mechanism (hypertonicity, direct histamine release from mast cells and basophils, complement activation, anaphylaxis), remains a debated question. The authors report two anaphylactic shocks (grade 3, classification of Ring and Messmer) during coronary angiography with ioxaglate. Anaphylaxis is suggested by clinical history: chronology of accidents, symptoms, strong positivity of intradermal tests for ioxaglate (diluted 1:10000 and 1:1000) and in one case, recurrence of the symptoms. It appears that an allergological control must be performed after a severe reaction with radio contrast media, in order to prevent the occurrence of further accidents. Premedication may only provide apparent safety: it did not prevent a severe reaction in one of the two cases.     

Idiopathic anaphylaxis.

Anaphylaxis is an acute, life threatening event that can progress extremely rapidly. External allergens as causations have been identified over the last century. The most recently identified type of anaphylaxis is not caused by any external allergen and has been termed Idiopathic Anaphylaxis (IA). Two major types are Generalized or Angioedema with airway obstruction. IA is also classified by frequency of episodes and response to therapy. Therapy consists of acute emergency therapy and induction of remissions using prednisone, beta agonists, and H1 blockers. Control and remission are usually induced. IA occurs at all ages, and pediatric and geriatric IA are often special problems, as is a psychogenic form where no true reactions occur. Although appropriate management of IA, in general, has a good prognosis, several problems exist. Among these are failure to accept IA as an entity or in an individual case by physicians and patients. A different problem occurs when the recommended treatment is used and there is control of IA, but only with persisting high doses of prednisone. This is corticosteroid dependent IA. The lack of defined mechanisms that will lead to improved therapies and wider acceptance of IA as an entity remains a major problem. Undifferentiated Somatoform IA is a serious management problem for physicians.     

A population-based study of the incidence, cause, and severity of anaphylaxis in the United Kingdom

BACKGROUND: Anaphylaxis is an acute and potentially fatal systemic reaction usually caused by mast cell-mediated release of histamine. Symptoms can vary in onset, appearance, and severity. Some common symptoms include weakness, dizziness, flushing, angioedema, urticaria, nasal congestion, and sneezing. Severe symptoms include upper respiratory tract obstruction, hypotension, vascular collapse associated with angioedema and urticaria, gastrointestinal distress, cardiovascular arrhythmias, and/or arrest. METHODS: We conducted an observational follow-up study encompassing approximately 8 million person-years based on the UK General Practice Research Database for the period January 1, 1994, to December 31, 1999, which quantified the frequency, type, and severity of a clinical diagnosis of anaphylaxis. RESULTS: Based on 675 cases of anaphylaxis, we estimate the incidence to be 8.4 per 100 000 person-years. Approximately 10% of cases had hypotension and shock that required urgent treatment. The most common causes were insect stings and oral medicines. CONCLUSION: Anaphylaxis is an uncommon illness that has multiple causes and can be life-threatening.     

Allergy to the bites of blood-sucking insects: clinical manifestations

Blood-sucking insects and other arthropods may occur allergic reactions when stinging. Usually, inflammatory symptoms are mild with a locoregional extension. Pruritus may be painful and sometimes patients experienced a functional impotency. Systemic reactions are possible. Anaphylaxis is rare and rather observed with ticks (Ixodes and Argas) and kissing-bugs. The circumstances and mechanisms of the sting related to the knowledge of the insect biology elicit the clinical symptoms. Skin prick-tests are usually not practicable. Indeed, the diagnosis remains based upon anamnestic and entomological data because the poor sensibility of in vitro tests. However, some immunological investigations gave signs of interest for prospective studies. Symptomatic drugs and prevention advices must be purchased for exposed patients.     

Hypersensitivity reactions associated with recombinant tissue-type plasminogen activator and urokinase.

Anaphylaxis or angioedema in response to recombinant tissue-type plasminogen activator or urokinase have been reported in only a few isolated cases. Both agents are endogenous proteins and thus considered non-antigenic. Activation of fibrinolysis may per se facilitate anaphylactoid reactions by pathophysiologic pathways that are not well understood. We report a unique case, review the literature and discuss implication for the clinician. The 25-year-old patient underwent thrombolytic treatment for extensive thrombosis of pelvic and deep lower extremity veins. The patient developed protracted anaphylactoid reactions during recombinant tissue-type plasminogen activator continuous intravenous infusion. After changing treatment to urokinase, the same symptoms recurred with more severe intensity, despite corticosteroid premedication. Symptoms resolved within hours after treatment with histamine receptor blockers. This unique observation, i.e. sequential occurrence of anaphylactoid reactions during recombinant tissue plasminogen activator and urokinase treatments, adds to existing evidence for an unspecific non-antigenic pathomechanism, and for a class effect of thrombolytics. Steroids do not prevent, but histamine receptor blockers seem to be an effective treatment of this unusual complication of thrombolytic therapy.     

Non-steroidal anti-inflammatory drug hypersensitivity in children

IntroductionThere are rather few publications about hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAID) in the paediatric age. In this study, we aimed to assess the frequency of confirmed NSAID hypersensitivity in children with a previous reported reaction to NSAID in order to investigate the role of the drug provocation test (DPT) in the diagnostic workup and to explore the factors associated with confirmed NSAID hypersensitivity.MethodsWe conducted a retrospective analysis of the clinical files from every patient under 18 years old who attended two Portuguese paediatric allergy outpatient clinics, from January 2009 to August 2014, due to a suspected NSAID hypersensitivity.ResultsWe included 119 patients, with a median age of nine years (P₂₅–P₇₅: 5–14). Ibuprofen was the commonest implicated NSAID in the patients’ reports (n = 94–79%). After DPT, NSAID hypersensitivity was confirmed in nine (7.6%) patients, excluded in 93 (78.2%) and was inconclusive in 17 (14.3%). In the majority (n = 95–79.8%), the reaction occurred in the first 24 h after intake. Eighty-four patients (70.6%) reported only cutaneous manifestations and 18 (15.1%) had systemic symptoms. Anaphylaxis represented a relative risk to NSAID hypersensitivity confirmation. No association was found for atopy and the number of previous reactions.ConclusionIn our study, NSAID hypersensitivity was confirmed in a small proportion of the patients with a previous reported reaction. Ibuprofen was the most implicated drug with urticaria/angio-oedema as the commonest manifestation. Anaphylaxis was associated with confirmed drug hypersensitivity. The drug provocation test was essential to establish the diagnosis.     

Anaphylactic shock: pathophysiology, recognition, and treatment

Anaphylaxis is a systemic, type I hypersensitivity reaction that often has fatal consequences. Anaphylaxis has a variety of causes including foods, latex, drugs, and hymenoptera venom. Epinephrine given early is the most important intervention. Adjunctive treatments include fluid therapy, H (1) and H (2) histamine receptor antagonists, corticosteroids, and bronchodilators; however these do not substitute for epinephrine. Patients with a history of anaphylaxis should be educated about their condition, especially with respect to trigger avoidance and in the correct use of epinephrine autoinjector kits. Such kits should be available to the sensitized patient at all times.     

Benzodiazepine withdrawal syndrome: a literature review and evaluation

The capacity of the benzodiazepine drugs to produce dependence and addiction has been associated with what has recently been recognized as a benzodiazepine withdrawal syndrome. Abrupt discontinuation of benzodiazepine treatment may show a spectrum of symptoms similar to those observed from withdrawal of alcohol or barbiturates. Such reactions have been reported with and are reviewed for the following drugs: chlordiazepoxide, diazepam, oxazepam, lorazepam, nitrazepam, temazepam, and clobazam. Generally, the higher the dose and the longer the benzodiazepine is taken, the greater the risk of developing withdrawal symptoms. However, withdrawal symptoms may occur in patients receiving recommended doses and/or short-term therapy. Although most withdrawal reactions have been reported with the long-acting benzodiazepines having psychoactive metabolites, reactions may also occur with the short-acting agents. In contrast, rebound insomnia occurs with greater frequency and severity with the short-acting agents. Benzodiazepine therapy should be stopped as early as possible, with tapering after moderate dose and/or prolonged use therapy.     

Choc anaphylactique au cours d’une anesthésie : de la physiologie au traitement

The incidence of allergic reactions occurring during anesthesia in France is estimated to be from 1:3500 to 1:13 000 anesthesias. Anaphylaxis, the most serious form, can be expressed in a single organ, for example, as bronchospasm, or as isolated cardiac arrest. The most frequent mechanism of these reactions is immunologic, IgE-mediated or otherwise; other mechanisms are non-immunologic. Treatment of these reactions is an emergency, whatever the mechanism. It is well standardized and depends on the severity of the reaction. Symptomatic treatment should be started upon observing local cutaneous signs. When there is significant hypotension, rapid vascular loading and administration of epinephrine are necessary, even in the presence of tachycardia; the size of the epinephrine bolus must be adapted to the severity of the reaction. Bronchospasm must be treated with epinephrine when administration of a beta-2 agonist is ineffective. When there is cardiac arrest, the classical resuscitation measures for cardio-respiratory failure are required. Following a perioperative anaphylactic reaction, an allergy workup should be done to identify the drugs administered and the mechanism involved. The results of this workup must be taken into account during future operative procedures.     

Jellyfish envenomation syndromes updated

Jellyfish venoms are mixtures of toxic and/or antigenic polypeptides and enzymes pathogenic to human beings. As newer therapeutic agents become available to treat the various reactions to stings caused by these animals, an accurate diagnosis of the type of reaction the patient experiences and of the offending species will be necessary. Fatal reactions may be caused either by anaphylaxis or by the action of toxins in the venom on the heart, respiratory center, or kidneys. Cutaneous eruptions after envenomation may be local, generalized, exaggerated, recurrent, delayed, persistent, or occur at sites distant from the primary sting. Fat atrophy, pigmentary changes, vasospasm, and contractures with gangrene can occur after jellyfish stings. Identification of the envenoming animal can be made by actual visualization, examination for nematocysts on skin scraping, or serologically. It may also be predicted based on knowledge of location, time, and environmental circumstances of the encounter. First-aid measures designed to prevent additional nematocyst rupture are species-specific. Anaphylaxis should be prevented by the appropriate lifesaving measures. Other syndromes, caused by the toxins of the venom or mediated by humoral or cellular immune mechanisms, should be treated specifically.     

Delayed selective reaction to clavulanic acid: a case report.

Clavulanic acid, an inhibitor of beta-lactamases, is widely used for antimicrobial therapy in association with beta-lactam antibiotics. Despite this, very few adverse reactions to the molecule have been described so far. We report a case of not-immediate reaction to clavulanic acid in a young adult who previously tolerated it. The patient complained of generalized itchy erythema two days after completing a course of amoxicillin-clavulanate therapy, and had no previous clinical history of adverse reactions to drugs. Intradermal and skin prick tests with beta-lactam determinants were negative, as well as the oral tolerance test with amoxicillin. Since no commercial preparation of clavulanic acid alone is available, we performed intradermal and skin prick test with the association amoxicillin-clavulanate, that elicited a delayed (24 and 48 hours) response. IgE-mediated reactions to clavulanic acid are rare, since this molecule is poorly allergenic. Based on the onset time and the specificity of the response we hypothesize that a delayed (possibly T-cell mediated) reaction has occurred.     

Tako-Tsubo-like syndrome during anaphylactic reaction

Tako-Tsubo's syndrome (apical ballooning or broken heart syndrome) is a reversible left ventricular dysfunction due to apical asynergy that occurs typically after sudden emotional stress in a subject without coronary disease. It is characterized by acute onset of chest pain or dyspnoea or both and is associated with electrocardiographic changes such as ST segment elevation and/or T wave inversion. Myocardial biomarkers may be normal or slightly elevated. Anaphylaxis is a severe, life-threatening, generalized hypersensitivity reaction, most often starting with urticaria and/or angioedema, that may involve cardiovascular and respiratory systems. Cardiovascular symptoms, including hypotension, cardiac arrhythmia and chest pain, are presumably linked to cardiac mast cell mediator release. We describe the case of a young woman who experienced a profound reversible cardiomyopathy with typical features of Tako-Tsubo's syndrome during an anaphylactic reaction.     

Gastrointestinal food allergies: do they exist?

Gastrointestinal (GI) symptoms are often attributed to adverse reactions to foods (ARF), but it is not always clear whether such reactions are caused by food allergy. A reaction to food proteins that is mediated by immunologic events is referred to as food allergy or food hypersensitivity. One of the most common types of food allergy is the IgE-mediated immediate hypersensitivity reaction to foods, which can give rise to dermatologic and respiratory tract symptoms in addition to GI complaints. Other GI forms of food allergy include food protein-induced enterocolitis or gastroenteropathy, celiac disease, and some cases of eosinophilic gastroenteritis. Because most patients complaining of adverse reactions to food have non-immune mechanisms for their complaints, it is important to distinguish the various types of ARF, as their management may differ substantially. Recent advances in the field of food allergy provide opportunities to improve diagnostic methods and develop new modalities for management that will complement the current practice of allergen avoidance.     

Idiopathic anaphylaxis

Anaphylaxis represents the maximal variant of an immediatetype allergic reaction involving the whole organism with manifestations in different organ systems. IgE-mediated mast cell and basophil activation is the major pathomechanism; however, immune complex and pseudo-allergic reactions also may lead to the same symptomatology. The most common elicitors are drugs, additives, occupational substances, animal venoms, aeroallergens, and contact urticariogens but also physical factors (cold, heat, ultraviolet light, exercise). When no eliciting factors can be detected, the term “idiopathic anaphylaxis’ is used. The diagnosis of idiopathic anaphylaxis is, therefore, a diagnosis of exclusion and may be made only after careful allergy history taking and diagnosis involving in vitro tests. Possible mechanisms underlying the pathophysiology of idiopathic anaphylaxis include undetected diseases (eg, mastocytosis occulta), concomitant anaphylaxis-enhancing medication (a-blockers), secretion of histamine-releasing factor from T lymphocytes, autoantibodies against IgE or IgE receptors, and angiotensin II deficiency. One of the many differential diagnoses of anaphylaxis may have been overlooked. The treatment of idiopathic anaphylaxis follows the rules of antianaphylactic therapy.     

The mechanisms, causes, and treatment of anaphylaxis.

Anaphylaxis is a severe life-threatening systemic reaction that offers many challenges to the clinician. The incidence of anaphylaxis is significant in the general population and an important cause of morbidity and mortality. While the most common causes of anaphylaxis include drugs, foods, and venoms, other important etiologies must be considered. The etiology of anaphylaxis is classically based on IgE mediated hypersensitivity but multiple mechanisms may be involved. The clinical presentation of anaphylaxis may be extremely variable with a broad differential diagnosis which will be outlined. Although the diagnosis of anaphylaxis can many times be based on a careful history and physical examination, there are laboratory and skin tests which may be helpful in establishing a diagnosis in some cases. The cornerstone of treatment of anaphylaxis remains epinephrine. Other supportive therapies will be discussed.     

Autoimmune reaction to a liver specific membrane antigen during acute viral hepatitis.

Lymphocyte cytotoxicity for isolated hepatocytes has been demonstrated in 93% of cases of acute viral hepatitis tested within two weeks of the onset of symptoms. The frequency of cytotoxicity during this time was similar for HBsAg positive and negative cases. However, after this time it was significantly higher in HBsAg positive than negative cases, 90% and 25% respectively (P less than 0-01). Cytotoxicity was found in B-cell, but not T-cell, enriched fractions of lymphocytes, compatible with an antibody-dependent K-cell mediated reaction. In two cases the assay remained positive on retesting six months later, and follow-up liver biopsies showed the features of chronic aggressive hepatitis. These findings suggest that, in addition to the known immunological reactions against viral antigens that occur during the acute phase of viral hepatitis, an autoimmune reaction directed against a liver specific protein is also initiated; and if this reaction persists then chronic hepatitis may develop.     

Growth hormone therapy and hypersensitivity type III reaction: a contraindication for desensitization

Allergic reactions against GH are rare, and usually represented by the hypersensitivity type I (IgE-mediated). This type of reaction can be treated by desensitization. In this case report, we present a patient showing an allergic reaction soon after starting GH therapy mediated by immune complex (hypersensitivity type III reaction). In this condition, the attempt to perform the desensitization procedure can perpetuate immune complex deposition determining a life threatening renal and respiratory insufficiency.     

Double blind, placebo controlled food reactions do not correlate to IgE allergy in the diagnosis of staple food related gastrointestinal symptoms.

BACKGROUND: The mechanisms for adverse reactions to foods in the gastrointestinal tract are poorly understood. There is conflicting evidence in the literature on the role for IgE mediated allergy in gastrointestinal reactions to staple foods. AIM: The aim was therefore to study the role of IgE mediated allergy in a group of patients with a history of gastrointestinal symptoms related to staple foods (cows' milk, hens' egg, wheat and rye flour) verified in double blind placebo controlled challenges (DBPCFC). PATIENTS: Fifteen patients with DBPCFC, identified by screening of 96 consecutive patients referred to our allergy clinic for investigation of suspected gastrointestinal symptoms due to staple foods. METHODS: The screening included diaries as well as elimination diets and open and blinded food challenges. The frequency of atopy were compared between the double blind positive and double blind negative patients. RESULTS: The positive DBPCFC in the 15 patients included eight patients with milk intolerance, four with wheat flour, two with egg, and one with rye flour. There was no indications of an allergic pathogenesis in all 15 patients with positive DBPCFC, as the skin prick test and radioallergosorbent test were negative for the relevant allergens. The frequency of atopy was four of 21 (19%) in the double blind negative group and three of 15 (20%) in the double blind positive group. CONCLUSION: In adult patients with staple food induced gastrointestinal symptoms, objectively verified by DBPCFC, there were no indications of IgE mediated allergy to the relevant foods suggesting other mechanisms in adults than in children. Future studies may include measures of local events in the shock organs in relation to food intake, for instance utilising inflammatory markers in jejunal fluids.