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

Clinical features, severity, and immunological changes during venom immunotherapy in children and adults

Background: Hymenoptera venom allergy (HVA) is among the most common causes of severe allergic reactions worldwide. Objective: To investigate clinical features and factors that affect the severity of HVA and to determine the alterations in immunologic biomarkers after venom immunotherapy (VIT). Methods: Seventy-six adults and 36 children were prospectively investigated. We analyzed specific immunoglobulin E (sIgE) and sIgG4 levels of venom extracts and components (rApi m1, rApi m10, rVes v1, rVes v5, rPol d5) before and after the first year of VIT. Results: Although cardiovascular symptoms were more common in adults (p < 0.001), the skin was the most affected organ in children (p = 0.009). Serum basal tryptase (sBT) levels were higher in the adults than the children (p < 0.001). The absence of urticaria (odds ratio [OR] 4.208 [95% confidence interval {CI}, 1.395-12.688]; p = 0.011) and sBT ≥ 5.2 ng/mL (OR 11.941 [95% CI, 5.220-39.733]; p < 0.001) were found as the risk factors for grade IV reactions. During VIT, changes in sIgE levels were variable. In the Apis VIT group, we observed remarkable increases in sIgG4 levels in Apis extract and rApi m1 but not in Api m10. Vespula extract, rVes v1, and rVes v5 sIgG4 levels were significantly increased in Vespula VIT group, we also detected significant increases in the Polistes extract and rPol d5 sIgG4 levels, which were not observed in the Apis VIT group. In the patients who received both Apis and Vespula VIT, increases in sIgG4 levels were observed for both venoms. Conclusion: Adults and children can have different clinical patterns. After 1 year, VIT induced a strong IgG4 response. Although Apis immunotherapy (IT) induced Apis sIgG4, excluding Api m10, Vespula IT induced both Vespula and Polistes sIgG4.

The role of molecular diagnosis in anaphylactic patients with dual or triple-sensitization to Hymenoptera venoms

BACKGROUND

The poly-sensitization to Hymenoptera venom makes it difficult to select genuine allergens for immunotherapy and increases patients' costs. The objective of this study was to determine the culprit allergen in dual or triple-sensitized patients to three Hymenoptera venoms through molecular diagnosis and evaluating the results of incorporating the molecular diagnosis with skin tests.

METHODS

Thirty-two patients with anaphylactic reactions and dual or triple-sensitization to Hymenoptera venoms in skin tests entered this study. IgE-sensitization to whole extracts and molecules of Apis mellifera (Api m), Vespula vulgaris (Ves v), and Polistes dominulus (Pol d) was evaluated utilizing ALEX or ImmunoCAP.

RESULTS

Twenty-nine patients (90.6%) were male. IgE-sensitization to at least one of the allergenic molecules related to Apis mellifera, Vespula vulgaris, and Polistes dominulus was seen in 59.4, 53.1, and 21.9%, respectively. Among 32 patients, 14 (43.8) and 8 (25%), were mono-sensitized to Api m and Ves v components in ALEX, respectively. Double sensitization to Hymenoptera was identified in 18.8% of patients in ALEX. Api m 1+/Api m 2-/Api m 10- and Ves v 1+/Ves v 5+ demonstrated the most prevalent sensitizations patterns in our patients.

CONCLUSIONS

The molecular diagnosis of IgE-sensitization to Hymenoptera venoms can be valuable, especially in patients who show dual or triple-sensitization in skin tests, as the ALEX results revealed mono and double-sensitization to Hymenoptera venoms in 22 and 6 patients, respectively. Regarding the high cost and adverse reactions of venom immunotherapy, especially for two or three venoms, incorporating the molecular diagnosis alongside skin tests for accurate diagnosis of the culprit venom could help decrease costs for patients.

Precision Medicine in Hymenoptera Venom Allergy: Diagnostics, Biomarkers, and Therapy of Different Endotypes and Phenotypes

Allergic reactions to stings of Hymenoptera species may be severe and are potentially fatal deviations of the immunological response observed in healthy individuals. However, venom-specific immunotherapy (VIT) is an immunomodulatory approach able to cure venom allergy in the majority of affected patients. An appropriate therapeutic intervention and the efficacy of VIT not only depend on a conclusive diagnosis, but might also be influenced by the patient-specific manifestation of the disease. As with other diseases, it should be borne in mind that there are different endotypes and phenotypes of venom allergy, each of which require a patient-tailored disease management and treatment scheme. Reviewed here are different endotypes of sting reactions such as IgE-mediated allergy, asymptomatic sensitization or a simultaneous presence of venom allergy and mast cell disorders including particular considerations for diagnosis and therapy. Additionally, phenotypical manifestations of venom allergy, as e.g. differences in age of onset and disease severity, multiple sensitization or patients unsusceptible to therapy, are described. Moreover, biomarkers and diagnostic strategies that might reflect the immunological status of the patient and their value for therapeutic guidance are discussed. Taken together, the increasing knowledge of different disease manifestations in venom hypersensitivity and the growing availability of diagnostic tools open new options for the classification of venom allergy and, hence, for personalized medical approaches and precision medicine in Hymenoptera venom allergy.

EAACI Allergen Immunotherapy User's Guide

Allergen immunotherapy is a cornerstone in the treatment of allergic children. The clinical efficiency relies on a well-defined immunologic mechanism promoting regulatory T cells and downplaying the immune response induced by allergens. Clinical indications have been well documented for respiratory allergy in the presence of rhinitis and/or allergic asthma, to pollens and dust mites. Patients who have had an anaphylactic reaction to hymenoptera venom are also good candidates for allergen immunotherapy. Administration of allergen is currently mostly either by subcutaneous injections or by sublingual administration. Both methods have been extensively studied and have pros and cons. Specifically in children, the choice of the method of administration according to the patient's profile is important. Although allergen immunotherapy is widely used, there is a need for improvement. More particularly, biomarkers for prediction of the success of the treatments are needed. The strength and efficiency of the immune response may also be boosted by the use of better adjuvants. Finally, novel formulations might be more efficient and might improve the patient's adherence to the treatment. This user's guide reviews current knowledge and aims to provide clinical guidance to healthcare professionals taking care of children undergoing allergen immunotherapy.

Clinical Characteristics of Allergy to Hymenoptera Stings

OBJECTIVE

The purpose of this study was to evaluate the clinical characteristics of allergy to stings from the Hymenoptera order of insects in a hospital in Thailand.

METHODS

A descriptive retrospective analytical study was carried out in inpatients and outpatients suffering from Hymenoptera stings from 2009 to 2013 in Siriraj Hospital.

RESULTS

Medical records of 386 patients with an allergy to Hymenoptera stings were evaluated. Anaphylaxis was more common in patients younger than 15 years, who comprised 22.3% of patients in this study. The most common sting type was from wasps (58.3%). Eighty-five percent of patients sought medical treatment less than 24 hours after being stung. A systemic reaction and anaphylaxis were found in 9.9% and 4.4% of subjects, respectively. In 17 patients with anaphylaxis, only 11 patients (64.7%) received an epinephrine (adrenaline) injection as treatment, and only 8 (47.1%) received epinephrine autoinjectors or epinephrine-prefilled syringes to prevent a possible subsequent severe reaction. Significantly more patients younger than 15 years received epinephrine for prevention of an allergic reaction than did those older than 15 years (87.5% vs 11.7%, P < 0.001). Antibiotics were given to 43.0% of patients.

CONCLUSIONS

Anaphylaxis from Hymenoptera stings was more common in children than in adults. Only half of the patients visited the emergency room within 1 hour of being stung. Overuse of antibiotics and underuse of epinephrine were found. More information about Hymenoptera stings should be provided to the public, and the use of epinephrine should be encouraged in the case of severe reactions and anaphylaxis.

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.

Subcutaneous venom immunotherapy in children: Efficacy and safety

BACKGROUND

Venom immunotherapy (VIT) is safe in children, although adverse effects can occur.

OBJECTIVE

To document adverse effects and to determine re-sting reactions and the efficacy of VIT in childhood.

METHODS

We retrospectively analyzed data from children who had taken VIT from 2002 through 2015. These patients were queried by telephone to determine reactions after re-stings during or after VIT.

RESULTS

In total 107 children with a systemic reaction after Hymenoptera sting and with proved immunoglobulin E-mediated sensitization were enrolled. Participants had a median age of 10.0 years (7.2-12.4 years) at the beginning of immunotherapy. Fifty-two participants had allergic reactions during VIT; 40 of these reactions were local (37.4%), 5 were large local (4.7%), and 7 were systemic (6.5%). Of the 52 patients with adverse reactions, most reactions were local (n = 40, 89%) and were observed mainly in dose-increase periods (n = 25, 60%; P < .001). Although local reactions were more frequently seen with Vespula treatment (P = .047), systemic reactions were common with Apis treatment (P = .031). Sixty-eight patients (63.5%) were queried for re-sting, 33 (48.5%) had a re-sting and 24 (72.7%) of these 33 patients developed allergic reactions. The reactions were local (n = 19), large local (n = 1), and systemic (n = 4). Risk analysis for local and systemic reactions during VIT showed pre-existing asthma as an independent risk factor (odds ratio 4.1, 95% confidence interval 1.3-12.7, P = .016).

CONCLUSION

In children, VIT appears to be safe and protective against severe reactions after re-sting. However, pre-existing asthma was identified as a risk factor for systemic and large local reactions during VIT in children.

Hymenoptera stings in the head region induce impressive, but not severe sting reactions

Stings in the head region are considered to be a risk factor for severe systemic reactions to hymenoptera stings. We supposed that stings in skin areas, which are well supplied with blood, lead to more severe reactions and tested our hypothesis in 847 patients with confirmed hymenoptera venom allergy. However, symptom severity was independent from sting site: only 16.3% of patients with severe reactions were stung on the head (P = 0.017). But we confirmed age > 40 years (P < 0.001) as well as elevated basal tryptase levels (P = 0.001) as risk factors. Taking antihypertensive drugs seemed to have an influence: 41.7% of patients taking antihypertensive drugs experienced a severe reaction compared to 29.5% of patients, not taking such drugs (P = 0.019). However, considering patients' age in regression analysis, taking antihypertensive drugs had no effect on symptom severity (P = 0.342). Importantly, in most patients with severe reactions, cutaneous signs were absent (P < 0.001).

Clinical Evaluation of High-Volume Hemofiltration with Hemoperfusion Followed by Intermittent Hemodialysis in the Treatment of Acute Wasp Stings Complicated by Multiple Organ Dysfunction Syndrome

Multiple organ dysfunction syndrome (MODS) is a rare complication of wasp stings. Currently, there is no standardized treatment for MODS secondary to multiple wasp stings, although blood purification techniques are often used. This study aimed to analyze our experiences of using intermittent hemodialysis (IHD) with or without high-volume hemofiltration (HVHF) for treating acute wasp stings complicated by MODS. In this retrospective study, 36 patients with wasp stings complicated by MODS received either IHD combined with hemoperfusion, or HVHF (ultrafiltration flow rate, 70 mL/kg/h) combined with hemoperfusion for 5 days followed by IHD. Clinical symptoms, blood biochemical parameters, duration of mechanical ventilation, use of vasoactive agents, duration of hospital stay and survival rate were recorded, and Acute Physiology and Chronic Health Evaluation II (APACHE II) and multiple organ dysfunction (MOD) scores estimated. Patients treated with HVHF followed by IHD appeared to exhibit a faster recovery than those receiving IHD alone, as evidenced by superior improvements in MOD (4.29±1.08 vs. 2.27±1.07) and APACHE II (7.09±2.62 vs. 4.20±1.69) scores (P < 0.05). Patients treated with HVHF had significantly lower myoglobin, creatine kinase-MB, lactate dehydrogenase, bilirubin and creatinine levels than patients treated with IHD alone. In addition, the durations of hospital stay (13.15±2.77 vs. 27.92±3.18 days), vasopressor use (1.76±0.24 vs. 3.43 ± 1.01 days), mechanical ventilation (3.02±1.63 vs. 5.94 ± 2.11 days) and oliguria (6.57±2.45 vs. 15.29 ± 3.51 days) were reduced, and renal function more often recovered (85.1% vs. 53.1%), in the HVHF group compared with the IHD group (P < 0.05). These results raise the possibility that HVHF plus IHD may be superior to IHD alone for the treatment of acute wasp stings complicated by MODS; additional prospective studies are merited to explore this further.

Stinging insect allergy: current perspectives on venom immunotherapy

Systemic allergic reactions to insect stings affect up to 5% of the population during their lifetime, and up to 32% of beekeepers. Such reactions can be fatal, albeit very rarely, and fear of a further systemic reaction (SR) can lead to significant anxiety and quality of life impairment. A recent Cochrane systematic review confirmed that venom immunotherapy (VIT) is an effective treatment for people who have had a systemic allergic reaction to an insect sting. VIT reduces risk of a further SR (relative risk 0.10, 95% confidence interval 0.03-0.28), but VIT also reduces risk of a future large local reaction, and significantly improves disease-specific quality of life. However, health economic analysis showed that VIT is generally not cost effective for preventing future SRs; most people are stung infrequently, most SRs resolve without long-term consequences, and a fatal outcome is extremely rare. VIT only becomes cost effective if one is stung frequently (eg, beekeepers) or if quality of life improvement is considered. Thus, for most people with insect sting allergy, anxiety and quality of life impairment should be the overriding consideration when making treatment decisions, highlighting the importance of a patient-centered approach. Areas which need to be explored in future research include efforts to improve the safety and convenience of VIT such as the use of sublingual immunotherapy; quality of life effects of venom allergy in children and adolescents as well as their parents; and the optimal duration of treatment.

Increased osteopontin levels in children undergoing venom immunotherapy may serve as a marker of clinical efficacy

BACKGROUND

Venom immunotherapy (VIT) has its effect by modulating various mediators resulting in immune tolerance. The aim of this study was to measure changes in plasma osteopontin (OPN) and serum basal tryptase (sBT) levels over the course of 1 year of VIT in children with venom allergy.

METHODS

Children who suffered from a large local reaction (LLR) or a systemic reaction (SR) after insect stings were included along with control subjects. Measurements were performed before the initiation of VIT and 6 and 12 months after it had been started.

RESULTS

A total of 58 children (24 with SR, 18 with LLR and 16 control subjects) with a median age of 9.5 years (range 6.7-12.8) were enrolled. The plasma OPN levels of patients with LLR [median 1,477 ng/ml, interquartile range (IQR) 1,123-1,772] were significantly higher than patients with SR (882 ng/ml, 579-1,086; p < 0.001) and healthy control subjects (1,015 ng/ml, 815-1,203; p = 0.002). A significant increase in plasma OPN levels in children was determined after the 1-year VIT. The sBT levels of children with SR (4.1 ng/ml, 3.6-5.8) were significantly higher than children with LLR (3.1 ng/ml, 2.5-4.0) and control subjects (3.0 ng/ml, 2.9-3.8; p = 0.001). There was no significant change in the sBT levels of the patients after the 1-year VIT.

CONCLUSIONS

The results of our study showed higher baseline levels of OPN in children with LLR compared to control subjects and children with SR. In children with SR, OPN levels were increased after the 1-year VIT. Our results may suggest a possible association between OPN and successful VIT in children.

An update on venom allergy

PURPOSE OF REVIEW

Allergic reactions to stinging insects may be unexpected, frightening, and severe. A clear understanding of recent advances in the field facilitates appropriate care of children who experience severe reactions to hymenoptera stings.

RECENT FINDINGS

Recent investigations have underscored the importance of appropriate patient selection for potentially life-saving venom immunotherapy. Venom immunotherapy is effective in preventing future anaphylaxis from hymenoptera stings. Immunotherapy is indicated for patients with a history of anaphylaxis. Children who develop large local swelling or strictly cutaneous systemic reactions generally do not require immunotherapy. Component resolved diagnostic testing has been investigated to clarify the possibility of multiple venom allergies in patients with sensitization to multiple venoms.

SUMMARY

Rapid recognition and treatment of anaphylaxis are critical. Subsequent education about avoiding future stings and attention to emergency preparedness with appropriate prescription of self-injectable epinephrine is important. Referral of patients who have experienced venom-associated anaphylaxis for possible venom immunotherapy can prevent future severe episodes of anaphylaxis resulting from stings.