The economic costs of severe anaphylaxis in France: an inquiry carried out by the Allergy Vigilance Network

BACKGROUND

The prevalence of severe anaphylaxis, between 1 and 3 per 10,000, has increased sharply over recent years, with a rate of lethality of 1%. The economic burden is unknown.

OBJECTIVE

The aim of this study was to estimate the economic costs of anaphylaxis, including direct costs of treatment, hospitalization, preventive and long-care measures, and the indirect cost: absenteeism.

METHODS

Analysis of 402 patients of anaphylaxis declared by 384 allergists was reported to the Allergy Vigilance Network. The global cost was estimated from the national data of hospital admissions: ICD-10 coding available for 2003, 2004 and 2005.

RESULTS

Three work/classroom days were lost per patient. Diagnosis required oral challenge with hospitalization in 18% of cases. The estimated mean total cost was 1895 euros for food- and drug-related anaphylaxis (5610 euros for the most severe), and 4053 euros for Hymenoptera anaphylaxis. National statistics recorded 2575 patients in 2005; 22% more than in 2003. The estimated annual cost was 4,789,500 euros. The possible reasons for this being an under-estimate include: data coming only from hospitalized patients, poor identification by medical teams unfamiliar with ICD-10 codes, peri-operative anaphylaxis being insufficiently declared, rush-immunotherapy and maintenance treatments for Hymenoptera anaphylaxis. Similarly, the extra cost of cow milk substitutes, as well as insurance costs where deaths are followed by litigation were not taken into account.

CONCLUSIONS

The mean cost of anaphylaxis was 1895-5610 euros in nonfatal patients. The prevalence was under-estimated because of many biases, leading to under-estimation of the national cost. Further studies would be necessary to evaluate the value of preventive strategies.

Epidemiology of life-threatening and lethal anaphylaxis: a review

Severe anaphylaxis is a systemic reaction affecting two or more organs or systems and is due to the release of active mediators from mast cells and basophils. A four-grade classification routinely places 'severe' anaphylaxis in grades 3 and 4 (death could be graded as grade 5). Studies are underway to determine the prevalence of severe and lethal anaphylaxis in different populations and the relative frequencies of food, drug, latex and Hymenoptera anaphylaxis. These studies will also analyse the risk arising from the lack of preventive measures applied in schools (personalized management protocols) and from the insufficient use of self-injected adrenalin. Allergy-related conditions may account for 0.2-1% of emergency consultations. Severe anaphylaxis affects 1-3 per 10 000 people, but for the United States and Australia figures are even higher. It is estimated to cause death in 0.65-2% of patients, i.e. 1-3 per million people. An increased prevalence has been revealed by monitoring hospitalized populations by reference to the international classification of disease (ICD) codes. The relative frequency of aetiological factors of allergy (food, drugs, insects and latex) varies in different studies. Food, drug and Hymenoptera allergies are potentially lethal. The risk of food-mediated anaphylaxis can be assessed from the number of personalized management protocols in French schools: 0.065%. Another means of assessment may be the rate of adrenalin prescriptions. However, an overestimation of the anaphylaxis risk may result from this method (0.95% of Canadian children). Data from the literature leads to several possibilities. First, a definition of severe anaphylaxis should be agreed. Secondly, prospective, multicentre enquiries, using ICD codes, should be implemented. Moreover, the high number of anaphylaxis cases for which the aetiology is not identified, and the variation in aetiology in the published series, indicate that a closer cooperation between emergency specialists and allergists is essential.

[Allergies in orthodontics]

In contrast with work-related allergies amongst dentists and dental prosthetictists, allergies in patients followed in orthodontics concerning the materials placed in the mouth were rare. It may be a question of limited manifestations in the buccal cavity (urticaria, angio-oedema, stomatitis, chellitis), or more generalised manifestations (Quincke's oedema, eczema). The number of materials used in orthodontics is limited. The observations concerning metals are less numerous whilst those that concern the resins are exceptional. On the other hand, the risk linked to latex is very real. Allergy investigations require skin tests, sometimes to mucous tests and in some cases to provocation tests. Use of eviction measures may be not only the only diagnostic method but also a therapeutic method. Systematic search for an allergy to metal or a resin posed by the prosthetic material does not seem to be necessary. In the case of suspicion of latex, confirmed ultimately by an allergic history, this imposes start of the eviction measures.

[Use of an amino-acid-based formula in the treatment of cow's milk protein allergy and multiple food allergy syndrome]

Food allergy to cow's milk proteins (APLV) is frequently found in young infants. Treatment is by starting an elimination diet. Different substitution products have been proposed: soya milk, partial hydrolysate of the proteins of lactoserum, powdered casein hydrolysate, hydrolysed soya and pork collagen. Allergic reactions to soya milk, hydrolysates of lactoserum proteins, powdered casein hydrolysates and hydrolysates of soya have been described. The study that we present evaluates the effect on the natural development of these allergies of a formula based on amino-acids (Neocate) in 26 patients who presented a syndrome of multiple allergies one of which was a food allergy to milk. Twenty-five of them had a severe atopic dermatitis, isolated (14 cases), or associated with gastro-intestinal troubles (6) break in the growth curve (5), anaphylactic reactions (2), one asthma (1). One child had a chronic diarrhoea associated with a weight plateau. Evaluation 2 or 3 months later showed a significant improvement of the atopic dermatitis. Return of the stature-weight growth was noted in 4 children from 5, the check in one was reported as due to a initially unrecognised allergy to gluten. The recovery of the APLV was shown by double-blind oral provocation test in 20/23 children between 11 and 37 months (22 +/- 9). Duration of administration of Neonate was between 6 to 19 months (12 + 5) months. This study confirmed the beneficial effect of the amino-acid formula on weight gain, gastro-intestinal troubles and development of atopic dermatitis. The level of recovery of APLV of 86% at the age of 2 years is better than that reported in the syndrome of multiple food allergies of 22%. The influence of this diet on the development of other food allergies remains to be evaluated.

Food anaphylaxis in schools: evaluation of the management plan and the efficiency of the emergency kit

BACKGROUND

Children with severe food allergies can benefit from a personalized care project (PCP) in schools. The usefulness of the PCP and the residual risk of allergic emergencies are poorly appreciated. The objective was to evaluate the efficiency of the management plan and the training in the use of the emergency kit.

METHODS

A telephone survey using a detailed questionnaire was performed in 45 families whose children had been previously referred to the department. The distribution of disorders was as follows: asthma, 37.7%; atopic dermatitis and asthma, 28.8%; atopic dermatitis, 15.5%; angioedema and urticaria, 13.3%; and anaphylactic shock, 4.2%. Food allergy had been diagnosed in the 45 children by past history, and double-blind or single-blind, placebo-controlled food challenges (DBPCFCs, or SBPCFCs) with evidence of specific IgE. Exactly 75.5% of the children had peanut allergy. Multiple food allergies characterized 46.8% of the subjects. They had benefited from a strict elimination diet and a protocol for emergency care including a ready-to-use intramuscular epinephrine injection. A PCP had been requested by the School Public Health Service.

RESULTS

Thirty-nine PCPs were implemented (86.5% of the requests). They represented 63% of the PCPs for food allergy in the eastern region of France: one per 5800 school-age children. The retrospective period of evaluation was 25 months on average. The types of meals were very diverse, and medically acceptable in 83% of cases. The place where the emergency kit was stored in the school varied. Forty reactions occurred in 33% of the children (5/6 times in the absence of a PCP), asthma in 28%, shock in 1%, and immediate skin reactions in 11%. Reactions occurred at home in 78% of the subjects, and in school in 22% of the subjects. The cause of the reactions was not specifically known in 63% of cases. Twenty-seven percent of the reactions were linked to the ingestion of food allergens. In 10% of subjects, the reaction was due to a modification of ingredients by the food industry.

CONCLUSIONS

The frequency of respiratory symptoms during oral challenge tests was confirmed by the frequency of asthmatic reactions within the follow-up period. The role of hidden allergens and of misleading labeling validates the need for PCPs in the case of peanut and tree nut allergies, past history of severe reactions, multiple food allergies, reactions to a low dose in DBPCFCs, and asthmatic reactions to foods. This study provides encouraging data on the usefulness of PCPs and confirms the need for thorough instruction and training of the school staff in dealing with allergic emergencies. Addition of a beta-agonist spray to the emergency kit is suggested.

Population study of food allergy in France

BACKGROUND

Food allergy (FA) is an important health problem for which epidemiologic studies are needed.

OBJECTIVE

We performed an epidemiologic survey in France to determine the prevalence, clinical pictures, allergens, and risk factors of FA.

METHODS

This study was conducted on 33,110 persons who answered a questionnaire addressed to a representative sample of the French population on a scale of 1:1000 (44,000 subjects aged </=60 years). One thousand one hundred twenty-nine persons with FA selected during phase 1 received a second questionnaire.

RESULTS

The reported prevalence of FA is 3.52%: 3.24% evolutionary FA; 0.12% asymptomatic cases thanks to eviction diets; and 0.17% cured FA. The subjects were characterized by overrepresentation of city dwellers (80% vs 76%), women (63% vs 50%), and health care personnel (11% vs 4%). Fifty-seven percent (vs 17%) presented with atopic diseases (P <.01). FA was often persistent, lasting more than 7 years in 91% of the adults. The most frequent allergens were 14% Rosaceae, 9% vegetables, 8% milk, 8% crustaceans, 5% fruit cross-reacting with latex, 4% egg, 3% tree nuts, and 1% peanut. Sensitization to pollen was significantly correlated with angioedema, asthma, rhinitis, and fruit allergy (P <.01). FA was 4 times more frequent in patients with latex allergy. The main manifestations of FA were atopic dermatitis for subjects under 6 years of age, asthma for subjects between 4 and 6 years of age, and anaphylactic shock in adults over 30 years of age (P <.007). Shocks were correlated with alcohol or nonsteroidal anti-inflammatory drug intake (P <.01 and P <.04, respectively).

CONCLUSION

The prevalence of FA is estimated at 3.24% (range, 3.04% to 3.44%) in France. This study emphasizes the increasing risk of FA in well-developed countries and draws attention to certain FA risk factors, such as the intake of drugs (nonsteroidal anti-inflammatory drugs, beta-blockers, and angiotensin-converting enzyme inhibitors) or alcohol, intolerance of latex gloves, and socioprofessional status.

[The multifood allergy syndrome]

Multiple food intolerance in infants and young children is increasingly diagnosed. More than 40% of infants less than 1 y.o. could be affected. The syndrome is characterized by the seriousness of atopic dermatitis (SCORAD > 50), by enterocolitis or failure to thrive or various associations of symptoms that may change over time. The evolution is long-lasting. Common food allergens are milk, egg, soy, wheat, but other ones can be implicated. The diagnosis is established by standardized oral challenges. Multiple etiopathogenic factors are involved: atopy, gastro-enteritis induced intestinal hyperpermeability, precocity of food diversification, breast-feeding continued after the onset of symptoms. Amino-acid based formulas have changed the evolution.

Cross-allergenicity of peanut and lupine: the risk of lupine allergy in patients allergic to peanuts

BACKGROUND

Peanut allergy is common, but cross-allergy between legumes is rare. Proteins from Lupinus albus are increasingly eaten in the form of seeds or additives to wheat flour. The risk of cross-allergenicity is still insufficiently known.

OBJECTIVE

We sought to study the risk of cross-allergy to lupine in patients allergic to peanut and to study lupine allergenicity.

METHODS

Twenty-four patients allergic to peanuts were studied by means of skin prick tests with native lupine flour from Lupinus albus. Double-blind oral challenge tests were performed with lupine flour and peanut in 8 of these patients. Specific IgEs were assayed for peanut, lupine flour, and pollen in 6 sera. RAST inhibition tests for lupine pollen by peanut were performed on 4 of these sera. Peanut and lupine flour immunoblots were carried out for 6 sera, and crossed immunoblot inhibitions for peanut by lupine flour and lupine flour by peanut were carried out for 2 sera.

RESULTS

The skin prick test responses with lupine flour were positive in 11 (44%) subjects. The challenge test responses were positive in 7 of 8 subjects at the same doses as with peanut. The major lupine flour allergen (molecular mass, 43 kd) is present in peanuts. The RAST inhibition and immunoblot tests indicated cross-reactivity of peanut with the lupine flour and pollen.

CONCLUSIONS

The risk of crossed peanut-lupine allergy is high, contrary to the risk with other legumes. The inclusion of 10% lupine flour in wheat flour without mandatory labeling makes lupine a hidden allergen, presenting a major risk of cross-reaction in subjects already allergic to peanut products. A high sensitizing potential can also be postulated for this legume.