An epidemiological survey of hymenoptera venom allergy in the Spanish paediatric population

Hymenoptera venom allergy in children and adolescents

PURPOSE OF REVIEW

This review will identify and summarize the published existing data pertaining specifically to Hymenoptera venom allergy in children and adolescents, highlighting the major studies currently available on venom immunotherapy (VIT) and its prognosis in children.

RECENT FINDINGS

The current review covers the incidence and prevalence of Hymenoptera venom allergy (HVA) in children, factors influencing occurrence and severity of reactions (age, sex, comorbidities, etc.), indications to perform diagnostic tests and start VIT in children, different existing VIT protocols and their safety and efficacy.

SUMMARY

Hymenoptera venom allergy is the second most common cause of anaphylaxis in children and it considerably affects quality of life. Cutaneous reactions are the most prevalent clinical presentation in children who usually have a more favourable prognosis than adult patients. However, studies on HVA in children and adolescents are still limited. Currently VIT is the only treatment able to modify the natural history of HVA in adults as well as in children, and to protect patients from systemic reactions after subsequent stings.

Venom allergy and knowledge about anaphylaxis among beekeepers and their families

BACKGROUND

Beekeepers and their families are at an increased risk of life-threatening anaphylaxis due to recurrent bee-sting exposures.

OBJECTIVE

The aim of this study is to evaluate the demographic features, previous history of anaphylaxis among beekeepers and their family members, and their knowledge about the symptoms and management of anaphylaxis.

METHODS

A standardized questionnaire was administered to beekeepers during the 6th International Beekeeping and Pine Honey Congress held in 2018, in Mugla, Turkey. Additionally, food-service staff from restaurants were surveyed as an occupational control group about their knowledge about anaphylaxis.

RESULTS

Sixty-nine beekeepers (82.6% male, mean age 48.4±12.0 years) and 52 restaurant staff (46.2% male, mean age 40.5±10.0 years) completed the questionnaire. Awareness of the terms 'anaphylaxis' and 'epinephrine auto-injector' among the beekeepers were 55.1% and 30.4% and among the restaurant staff were 23.1% and 3.8%, respectively. Of the beekeepers, 74% were able to identify the potential symptoms of anaphylaxis among the given choices; 2.9% and 5.8% reported anaphylaxis related to bee-stings in themselves and in their family members, respectively. None of the restaurant staff had experienced or encountered anaphylaxis before but 3.8% of their family members had anaphylaxis and those reactions were induced by drugs.

CONCLUSION

It is essential that implementation of focused training programs about anaphylaxis symptoms and signs as well as practical instructions of when and how to use an epinephrine auto-injector will decrease preventable morbidities and mortalities due to bee-stings in this selected high-risk population of beekeepers and their family members, as well as other fieldworkers under risk.

A longitudinal study of hymenoptera stings in preschool children

BACKGROUND

Insect venom is the second most common cause of anaphylaxis outside of medical encounters. Stings cause over 20% of all anaphylactic deaths and 7% of anaphylaxis in children. To date, there have been no longitudinal studies of insect sting events or allergy in preschool children.

METHODS

A prospective longitudinal nested observational study in the BASELINE Birth Cohort Study (n = 2137). Sting-related questions were asked at 6 and 12 months and 2 and 5 years. Skin prick testing (SPT) was performed at 2 and 5 years. SpIgE testing was performed on selected cases at 2 years.

RESULTS

Seventy-seven children (6.8%) were stung by the age of 2. Of these, 25 (32.5%) reported adverse reactions (four systemic). Eleven (0.9%) had positive SPT at 2 years (eight bee, two wasp, one both). Four stung children had positive SPT. Two (one stung, one never stung) had positive spIgE to a venom component at 2 years. A total of 268 children (21.9%) were stung by 5 years, 144 (52.1%) reporting local reactions and none systemic. Four children (0.4%) had positive SPT at 5 years: one bee and three wasp. Of the 11 SPT-positive children at 2 years, none were still positive at 5 years.

CONCLUSION

This is the first longitudinal study of the natural history of hymenoptera stings and allergy in preschool children. Hymenoptera venom allergy is less common in this cohort than in adults. Systemic reactions were not medically documented in this population, in keeping with previous literature. This study confirms the poor correlation of IgE sensitization to venom with sting allergy and does not support the common parental request to screen children for sting allergy.

A twenty-two-year experience with Hymenoptera venom immunotherapy in a US pediatric tertiary care center 1996-2018

BACKGROUND

The rate of systemic reactions (SRs) to venom immunotherapy (VIT) in children has not been well evaluated.

OBJECTIVE

To evaluate the rate of SRs to VIT in pediatric patients age 5 to 18 years who were treated with a standard protocol.

METHODS

A retrospective chart review was conducted to identify patients who received VIT at Boston Children's Hospital from 1996 through 2018. Information on venom testing, severity of reaction to insect field sting, and SRs to VIT were retrieved.

RESULTS

A total of 78 patients were included. Most had moderate to severe reactions to insect sting before VIT. The rate of SRs was 0.2% of injection visits, occurring in 9% of patients. The SRs from VIT were mild (mostly grade 1 and some grade 2), and no grades 3, 4, or 5 reactions were seen. Male sex was a significant risk factor for moderate to severe reactions to insect sting. Positive testing to vespinae was seen in 98.7% of patients, and none had exclusive sensitivity to honeybee. The severity of the initial, pre-VIT insect sting reactions in our patients did not correlate with the occurrence of SRs from VIT. Twenty-seven percent of the patients were subsequently stung while on VIT. Only 1 patient (5%) had a mild SR, while all others had only local or no reaction at all.

CONCLUSION

In the largest US study evaluating the safety of VIT in children, SRs to VIT were mild, and none required epinephrine. Male sex was significantly associated with higher risk of moderate to severe reactions to insect sting. Larger multicenter studies are needed to further evaluate the rate of SRs to VIT in pediatric patients.

Which immunotherapy product is better for patients allergic to Polistes venom? A laboratory and clinical study

BACKGROUND

Venom immunotherapy (VIT) is highly effective in preventing allergic reactions to insect stings, but the appropriate venom must be used to achieve clinical protection. In patients with multiple positive results to venoms, molecular allergy diagnostics or CAP-inhibition may identify the causative venom. Concerning allergy to venom from Polistes spp. it has been proposed that only the European species P. dominulus should be used for VIT. However, this recommendation is not present in any international guideline. Using both laboratory and clinical data, we aimed to evaluate the reliability of this proposal.

METHODS

We performed an in vitro study using CAP-inhibition to determine sensitization of 19 patients allergic to Polistes venom. The clinical study included 191 patients with positive tests to Polistes treated with VIT, 102 were treated with P. dominulus and 89 were treated with a mix of American Polistes (mAP).

RESULTS

The difference in % of inhibition was significant concerning inhibition of P. dominulus sIgE by P. dominulus venom (79.8%) compared with inhibition by mAP venom (64.2%) and not significant concerning the inhibition of mAP sIgE by P. dominulus venom (80.1%) and by mAP venom (73.6%). Instead, the clinical protection from stings was not statistically different between the two kinds of venom.

CONCLUSION

The data from CAP inhibition would suggest that the choice of either P. dominulus venom or mAP venom for VIT is appropriate in patients with CAP inhibition higher than 70%, but the clinical data show the same odds of protection from stings using for VIT P. dominulus or mAP venom.

Rush Venom Immunotherapy in Children

BACKGROUND

Rush venom immunotherapy (VIT) is highly effective in Hymenoptera venom allergy. Still, specific data regarding its safety and efficiency in children are rather sparse.

OBJECTIVES

The objective of this study was to better evaluate the safety and efficiency of rush VIT in this specific age group.

METHODS

Children younger than 16 years with systemic reaction to insect sting involving, at least, one body system other than skin and children aged 16-18 years with any kind of systemic reaction were offered conventional or rush VIT with a build-up phase that lasted 3 days.

RESULTS

Eighty-four of 127 children together with their caregivers chose to receive rush VIT. Seventy of them were allergic to bee venom only. There was no difference between the children receiving rush or conventional VIT in the incidence of systemic reactions during the build-up phase (19% and 23.2%, respectively), nor was there any difference in regard to the severity of these reactions. Efficiency was improved with rush VIT, as reflected by a higher number of patients achieving the 100 mcg maintenance dose with the primary protocol (83 of 84 patients, 98.8%, and 39 of 43, 90.7%, for rush and conventional, respectively, P = .04).

CONCLUSIONS

Rush VIT in children is as safe as and more efficient than conventional VIT.

Clinical contraindications to allergen immunotherapy: an EAACI position paper

Clinical indications for allergen immunotherapy (AIT) in respiratory and Hymenoptera venom allergy are well established; however, clinical contraindications to AIT are not always well documented. There are some discrepancies when classifying clinical contraindications for different forms of AIT as 'absolute' or 'relative'. EAACI Task Force on 'Contraindications to AIT' was created to evaluate and review current literature on clinical contraindications, and to update recommendations for both sublingual and subcutaneous AIT for respiratory and venom immunotherapy. An extensive review of the literature was performed on the use of AIT in asthma, autoimmune disorders, malignant neoplasias, cardiovascular diseases, acquired immunodeficiencies and other chronic diseases (including mental disorders), in patients treated with β-blockers, ACE inhibitors or monoamine oxidase inhibitors, in children under 5 years of age, during pregnancy and in patients with poor compliance. Each topic was addressed by the following three questions: (1) Are there any negative effects of AIT on this concomitant condition/disease? (2) Are more frequent or more severe AIT-related side-effects expected? and (3) Is AIT expected to be less efficacious? The evidence, for the evaluation of these clinical conditions as contraindications, was limited, and most of the conclusions were based on case reports. Based on an extended literature research, recommendations for each medical condition assessed are provided. The final decision on the administration of AIT should be based on individual evaluation of any medical condition and a risk/benefit assessment for each patient.

Facing Hymenoptera Venom Allergy: From Natural to Recombinant Allergens

Along with food and drug allergic reactions, a Hymenoptera insect Sting (Apoidea, Vespidae, Formicidae) is one of the most common causes of anaphylaxis worldwide. Diagnoses of Hymenoptera venom allergy (HVA) and specific immunotherapy (SIT) have been based on the use of crude venom extracts. However, the incidence of cross-reactivity and low levels of sensibility during diagnosis, as well as the occurrence of nonspecific sensitization and undesired side effects during SIT, encourage the search for novel allergenic materials. Recombinant allergens are an interesting approach to improve allergy diagnosis and SIT because they circumvent major problems associated with the use of crude venom. Production of recombinant allergens depends on the profound molecular characterization of the natural counterpart by combining some “omics” approaches with high-throughput screening techniques and the selection of an appropriate system for heterologous expression. To date, several clinically relevant allergens and novel venom toxins have been identified, cloned and characterized, enabling a better understanding of the whole allergenic and envenoming processes. Here, we review recent findings on identification, molecular characterization and recombinant expression of Hymenoptera venom allergens and on the evaluation of these heterologous proteins as valuable tools for tackling remaining pitfalls on HVA diagnosis and immunotherapy.

Clinical features of children with venom allergy and risk factors for severe systemic reactions

BACKGROUND

Severe systemic reactions (SRs) to insect venom are rare in childhood and there are few data on this study population. The aim of our study is to analyze the clinical features and to document the risk factors for severe SRs in children with insect venom allergy.

METHODS

Children with SRs after Hymenoptera sting were analyzed. The diagnosis was based on medical history, skin tests and/or specific IgE testing.

RESULTS

Seventy-six children were included [57 boys (75%), mean age 9.8 ± 3.4 years]. The mean age of children at the time of SR was 8.3 ± 3.4 years. Reactions were accounted for Vespula (wasp) venom in 58 (76%) and Apis mellifera (bee) venom in 18 (24%) patients. Twenty-six percent of patients had aeroallergen sensitization and 33% had atopic disease, whereas 66% had experienced previous stings. The upper limb was the most frequent area of sting (43%), and the cutaneous system (99%) was the most frequent involved system. SRs occurred in 59% of patients. Multivariate logistic regression analysis revealed eosinophilia (>5%) [odds ratio (OR) 12.6; confidence interval (CI) 1.5-109.7; p = 0.022], female sex (OR 6.4; CI 1.5-26.9; p = 0.011) and accompanying atopic disease (OR 3.4; CI 1.2-12.3; p = 0.016) as significant risk factors for severe SRs. Ninety-seven percent of patients were admitted to the emergency department; however, epinephrine was used in only 46% of patients.

CONCLUSIONS

There was a high frequency of hypersensitivity to wasp venom among the study population, and severe reactions were related to mild eosinophilia, female sex and concomitant atopic diseases. A better understanding of the risk factors may lead to effective utilization of health care sources in the future.