Review of venom immunotherapy at a regional tertiary paediatric centre.

AIM: Bee stings can result in allergic reactions, including anaphylaxis. Venom immunotherapy (VIT) is a definitive cure for bee venom allergy, but controversy surrounds whether accelerated protocols are safe in children. Our primary aim was to assess the safety profile of ultra-rush bee VIT compared with conventional bee VIT at a regional paediatric tertiary centre. We also sought to evaluate the impact of both approaches on time and resource use. METHODS: Data were collected retrospectively from 14 patients with bee venom allergy who were treated with ultra-rush or conventional bee VIT between 2013 and 2021 at John Hunter Children's Hospital. We compared VIT-associated adverse reactions and use of resources in both these groups. RESULTS: Overall, six patients received ultra-rush bee VIT and eight patients received conventional VIT. The ultra-rush group had a lower rate of systemic reaction (16%) compared with the conventional group (25%). One patient from the conventional group required adrenaline. Ultra-rush patients require fewer injections over a shorter time and fewer hospital visits to complete the protocol. Travel distance for families was significantly reduced. CONCLUSION: At our regional paediatric tertiary centre, ultra-rush bee VIT was a safe treatment option for children with bee venom allergy. It has many advantages over a conventional approach, especially for patients living in regional or remote areas.

Status epilepticus following vaccination in children aged ≤24 months: A five-year retrospective observational study.

BACKGROUND: Status epilepticus is associated with significant morbidity and mortality. While vaccine-proximate status epilepticus (VP-SE) has rarely been associated with cases of Dravet syndrome, it is not known whether VP-SE differs clinically from non-vaccine proximate status epilepticus (NVP-SE). METHODS: Medical records of children aged ≤24 months, presenting to one of five Australian tertiary pediatric hospitals with their first episode of status epilepticus from 2013 to 2017 were identified using ICD-coded discharge diagnoses. Vaccination history was obtained from the Australian Immunisation Register. Hospitalization details, subsequent epilepsy diagnosis, and vaccination uptake were compared between VP-SE and NVP-SE cases. RESULTS: Of 245 first status epilepticus hospitalization with immunization records, 35 (14%) were VP-SE and 21 (60%) followed measles-containing vaccines. Vaccine-proximate status epilepticus cases had a median age of 12.5 months [IQR 7.1-14.73], 23 (66%) were in males, 15 (43%) were febrile status epilepticus and 17 (49%) had an infection confirmed. There were no significant differences in hospitalization duration (P = 0.50) or intensive care unit admission (P = 0.42) between children with VP-SE compared to children with NVP-SE. Children with no history of seizures at their first VP-SE had longer hospitalizations, were more likely to require intensive care unit admission, but were less likely to have a subsequent diagnosis of epilepsy than children with previous seizures at their first VP-SE. CONCLUSION: First VP-SE was predominantly associated with a measles-containing vaccine at 12-months of age. Seizure severity was no different between first VP-SE and first NVP-SE. In children with VP-SE, subsequent seizure admissions and epilepsy diagnosis were associated with having seizure prior to their first SE.

Change in exhaled nitric oxide during peanut challenge is related to severity of reaction.

BACKGROUND: Peanut allergy affects 3% of Australian children and has a higher risk of anaphylaxis than most food allergies. Predicting who is likely to develop anaphylaxis is still an inexact science. The fraction of exhaled nitric oxide (FeNO) shows promise as a biomarker involved in peanut allergy, as nitric oxide plays a role in inhibiting mast cell degranulation which is relevant in anaphylaxis, where mast cell degranulation plays a mediator role. The aim of this study was to assess the change in FeNO in children during peanut challenge. METHODS: Thirty-six children aged from 5 to 17 years were recruited for open-labelled peanut challenge. Participants had skin prick test to peanut performed, and serum collected for Ara h2 specific IgE and peanut specific IgE. FeNO was measured by portable device (NIOX VERO) prior to and throughout the peanut challenge. RESULTS: When grouped according to reaction type at peanut challenge (anaphylaxis, clinical allergy not anaphylaxis and tolerant), there were significant differences in the mean change in FeNO measurement between the anaphylaxis group and the clinical allergy, not anaphylaxis group (p = 0.005), and between the anaphylaxis group and tolerant group (p < 0.0001). CONCLUSIONS: FeNO decreased more significantly in those who subsequently developed anaphylaxis than in those with clinical allergy, not anaphylaxis or negative peanut challenge (tolerance). As a bedside test that can be used in children, it has potential for further research into mechanisms of anaphylaxis in food allergy and potentially assists in predicting an imminent anaphylactic reaction in some patients.Trial registration ClinicalTrials.gov: PEAnut Anaphylaxis Predictors (PEAAP) NCT02424136.

Elevated Serum Tissue Transglutaminase Antibodies in Children With Eosinophilic Esophagitis.

OBJECTIVES: This study compared the clinical and histopathological characteristics of children with eosinophilic esophagitis (EoE) and elevated anti-transglutaminase (TTG Ab) with those with EoE and normal TTG Ab titres. METHODS: Single-center chart and blinded histopathological review of patients diagnosed with EoE for a 4-year period, who had esophageal and duodenal biopsies taken at time of endoscopy, and TTG Ab measured within 6 months of biopsy. Patients with histology-proven CD were excluded. RESULTS: Elevated TTG Ab was present in 19/34 (54%) of the study cohort, representing 23% of all patients diagnosed with EoE during the study period. Eight had titers >6× upper limit of normal (ULN) and 4 had >10× ULN. TTG Ab-positive patients were classified as having either potential CD with (n = 3, 16%) and without lymphocytic duodenosis (LD; n = 12, 63%), and no CD (n = 4, 21%) on human leukocyte antigen typing. There was an increase in duodenal eosinophils in patients with elevated TTG Ab (P = 0.01), which remained when patients with LD were excluded (P = 0.018). Of 19 patients with EoE and elevated TTG Ab, 5 responded to elimination diet involving exclusion of wheat, including 2 with a sole wheat trigger and TTG Ab >10× ULN that were CD-associated human leukocyte antigen-negative. CONCLUSIONS: Serum TTG Ab was elevated in almost one-quarter of our total EoE cohort, and at least 20% of these patients did not have potential CD, suggesting EoE is a heterogeneous disease with differing immune mechanisms activated in some patients. These findings also support routine esophageal biopsy during upper endoscopy in children with elevated TTG Ab.

Reproducibility of serum IgE, Ara h2 skin prick testing and fraction of exhaled nitric oxide for predicting clinical peanut allergy in children.

BACKGROUND: Ara h2 sIgE serum levels improve the diagnostic accuracy for predicting peanut allergy, but the use of Ara h2 purified protein as a skin prick test (SPT), has not been substantially evaluated. The fraction of exhaled nitric oxide (FeNO) shows promise as a novel biomarker of peanut allergy. Reproducibility of these measures has not been determined. The aim was to assess the accuracy and reproducibility (over a time-period of at least 12 months) of SPT to Ara h2 in comparison with four predictors of clinical peanut allergy (Peanut SPT, Ara h2 specific Immunoglobulin E (sIgE), Peanut sIgE and FeNO). METHODS: Twenty-seven children were recruited in a follow-up of a prospective cohort of fifty-six children at least 12 months after an open-labelled peanut food challenge. Their repeat assessment involved a questionnaire, SPT to peanut and Ara h2 purified protein, FeNO and sIgE to peanut and Ara h2 measurements. RESULTS: Ara h2 SPT was no worse in accuracy when compared with peanut SPT, FeNO, Ara h2 sIgE and peanut sIgE (AUC 0.908 compared with 0.887, 0.889, 0.935 and 0.804 respectively) for predicting allergic reaction at previous food challenge. SPT for peanut and Ara h2 demonstrated limited reproducibility (ICC = 0.51 and 0.44); while FeNO demonstrated good reproducibility (ICC = 0.73) and sIgE for peanut and Ara h2 were highly reproducible (ICC = 0.81 and 0.85). CONCLUSIONS: In this population, Ara h2 SPT was no worse in accuracy when compared with current testing for the evaluation of clinical peanut allergy, but had-like peanut SPT-poor reproducibility. FeNO, peanut sIgE and Ara h2 sIgE were consistently reproducible despite an interval of at least 12 months between the repeated measurements.

Non-invasive detection of microvascular changes in a paediatric and adolescent population with type 1 diabetes: a pilot cross-sectional study.

BACKGROUND: The detection of microvascular damage in type 1 diabetes is difficult and traditional investigations do not detect changes until they are well established. The purpose of this study was to investigate the combined ability of nailfold capillaroscopy, laser Doppler flowmetry, retinal vessel analysis and 24-hr ambulatory blood pressure monitoring to detect early microvascular changes in a paediatric and adolescent population with type 1 diabetes. METHODS: Patients aged between 8 - 18 years with type I diabetes and no other autoimmune conditions were studied. The participants underwent the above cardiac and vascular investigations in a single three-hour session. Standard parameters including HbA1c were also investigated. Associations between all parameters were described by correlation analysis. Fisher's exact and t-tests determined the association with clinical findings. RESULTS: 26 participants were recruited. The mean HbA1c was 8.1% (SD ± 1.1) with a mean duration of type 1 diabetes of 7.9 years (SD ± 3.4). Three participants had microalbuminuria and one had early signs of retinopathy. Participants with microvascular complications had more avascular areas on nailfold capillaroscopy (p = 0.03). Recent HbA1c was positively associated with the number of nailfold microhaemorrhages (p = 0.03) Decreased baseline perfusion by laser Doppler flowmetry was associated with increased capillary density (p = 0.001) and an increased number of microaneurysms (p = 0.04) on nailfold capillaroscopy. CONCLUSIONS: This pilot study has shown that in children and adolescents with established type 1 diabetes, abnormal microvasculature can be detected by these investigations. These markers were also positively associated with evidence of suboptimal diabetes control as assessed by HbA1c. Further research will be necessary to determine the practical role of these investigations in the management and progress of the complications of type 1 diabetes. TRIAL REGISTRATION: Clinical Trial number NCT01279928, ClinicalTrials.gov.