Ten-year outcomes of Perioperative Anaphylaxis Workup Study in Hong Kong (PAWS-HK): Performance of diagnostic modalities.

BACKGROUND: Studies on perioperative anaphylaxis (PA) in Asia are lacking. Furthermore, allergy workup for PA has largely been limited to the "silver standard" of skin tests (ST). Using in vitro tests as an adjunct to ST may improve and overcome these diagnostic challenges. OBJECTIVE: To evaluate the clinical characteristics and diagnostic tests of patients with suspected PA through the Perioperative Anaphylaxis Workup Study in Hong Kong cohort. METHODS: Patients with a diagnosis of PA over a 10-year period were recruited into the Perioperative Anaphylaxis Workup Study in Hong Kong. We reviewed the medical records, tryptase elevation, and diagnostic tests including ST, specific immunoglobulin E, and basophil activation tests (BAT). RESULTS: In 151 patients with PA, diagnosis was reached in three-fourths of the cases (113/151, 74.8%). The most common culprits identified were neuromuscular blocking agents (25.8%), ß lactams (17.2%) and chlorhexidine (13.9%). Severe anaphylaxis was associated with female sex, older age, elevated acute tryptase levels, and more cardiovascular manifestations during induction. Skin tests remained the most sensitive diagnostic modality overall (66.2%). BAT showed better performance for chlorhexidine and gelofusine anaphylaxis, with sensitivity of 80.0% and 79.6%, respectively. Specific Immunoglobulin E indicated even higher sensitivity (95.2%) than did ST (85.0%) and BAT (80.0%) for chlorhexidine anaphylaxis but performed poorly for other drugs. CONCLUSION: Neuromuscular blocking agents remain the most common culprit in PA. There was a higher prevalence of gelofusine anaphylaxis in our cohort than was seen in the literature. Skin tests remain the most sensitive testing modality. In vitro tests for chlorhexidine and gelofusine showed promising results, but more studies to further elucidate its use are warranted.

Disparities in chronic spontaneous urticaria: Eligibility for drug reimbursement associated with clinical outcomes.

Background: Chronic spontaneous urticaria (CSU) is an immunologic condition with an estimated prevalence of 0.1%. For CSU that is poorly controlled despite the use of antihistamines, omalizumab is the only treatment approved and recommended by international guidelines. Objective: Our aim was to outline the impact of treatment accessibility on CSU outcomes in the real world. Methods: Serial data on adult patients with CSU receiving care for at least 6 months at a dedicated, immunologist-led urticaria clinic at Grantham Hospital in Hong Kong between 2018 and 2023 were analyzed. Patients' clinicodemographic data, drug eligibility status (eligible for reimbursement or not), treatment step, and disease activity (weekly Urticaria Activity Score [UAS7]) were collected and compared according to drug eligibility status. Results: This study included 238 patients, 80 (33.6%) of whom were eligible for reimbursement and 158 of whom were not. No significant clinicodemographic differences, including disease activity, were found at baseline. At latest follow-up, significantly more patients in the eligible group were receiving omalizumab (28.7% vs 5.7% [P < .001]), which is equivalent to a multivariate odds ratio of 9.35 (95% CI = 3.689-23.703 [P < .001]). The discrepancy persisted even in patients with moderate-to-severe CSU whose UAS7 was 16 or higher (40.6% [13 of 32] vs 10.2% [6 of 59]; P < .001). In addition, there was significantly less dose reduction (<300 mg every 4 weeks) in the eligible omalizumab users (4.3% vs 44.4% [P = .015]). Clinically, significantly greater improvements in UAS7 were reported by the eligible group (median change -8.0 vs -5.0 [P = .021]). Conclusion: Patterns of management varied largely among patients with different drug eligibility statuses and led to disparities in health outcomes. More efforts to secure equitable access to guideline-based CSU care are warranted.

Clinical utility of and correlation between Sniffin' Sticks and TIB smell identification test (TIBSIT) among Hong Kong Chinese with or without chronic rhinosinusitis.

Introduction: Olfactory dysfunction (OD) is common among patients with chronic rhinosinusitis (CRS). Validated and culturally specific tests, such as the "Sniffin' Sticks" test (SST) and the TIB Smell Identification Test (TIBSIT), are crucial for the diagnosis and monitoring of OD. However, they have not been utilised in Hong Kong Chinese and their correlations are unknown. Methods: Twelve CRS patients and twenty healthy volunteers were prospectively recruited from a joint allergy-otorhinolaryngology clinic in Hong Kong and performed both SST and TIBSIT. Demographics, baseline characteristics and all test results were compared and analysed. Results: Patients with CRS demonstrated significantly lower test scores than healthy controls (all p < 0.001). Significant and strong correlations were observed between all composite and subtest scores, particularly between the composite SST and TIBSIT scores (ρ = 0.789, p < 0.001). Multivariate analysis demonstrated that the presence of CRS and increasing age were significantly associated with OD. Conclusion: Both SST and TIBSIT are useful olfactory tests and are strongly correlated among Hong Kong Chinese. We advocate that either test can be used for measuring OD among CRS patients.

Enhancing Patient-Reported Outcome Measures for Drug Hypersensitivity: A Validated 6-Item Quality-of-Life Questionnaire for Patients With Drug Hypersensitivity.

BACKGROUND: Drug hypersensitivity reactions (DHRs) can significantly impair patients' health-related quality of life (HRQoL). However, tools for HRQoL assessment for patients with DHR are time-consuming and remain underutilized. OBJECTIVE: To develop and validate an optimized version of the Drug Hypersensitivity Quality-of-Life Questionnaire (DrHy-Q) designed for everyday clinical use. METHODS: Item response theory (IRT), a statistical framework for psychometric measurement, was used to evaluate the 15 questions from the original DrHy-Q for their respective item difficulty, discrimination, and information using prospective data from 243 patients with histories of suspected/confirmed DHR before allergy workup. Accordingly, the best-performing items were identified to develop a 6-item optimized version (DrHy-Q6), which was subsequently validated with another prospective cohort of 156 patients. RESULTS: All 15 items of the original DrHy-Q demonstrated satisfactory parameters in IRT analysis, including very high discrimination (>1.7), appropriate difficulty (in between -1.5 and 1.5), and good information (a high and broad peak in the information curve). Six items with top-ranked IRT parameters were identified to construct an optimized version, which we named the DrHy-Q6. The DrHy-Q6 demonstrated a 1-factor structure with an improved fit compared with the original DrHy-Q (comparative fit index = 0.985, Tucker-Lewis index = 0.974), excellent convergent validity (unadjusted Pearson correlation with the full version = 0.955; adjusted = 0.894, P < .001), reliability (Cronbach's α and McDonald's ω = 0.93), divergent validity (Pearson correlation with all Short Form 12-item Health Survey Version 2 subscales <0.60, P < .001), and discriminant validity (significantly higher scores with multiple DHR labels [42.45 ± 27.26 vs 32.93 ± 26.66], P = .013). CONCLUSIONS: From an IRT perspective, the DrHy-Q and all its constituent items are psychometrically valid for HRQoL assessment. We propose an optimized 6-item version (DrHy-Q6) as an abbreviated alternative for assessing HRQoL in patients with DHR, especially for routine use in clinical practice. Patients and physicians may benefit from its streamlined length and simpler scoring algorithm.

Prospective, Multicenter, Head-to-Head Comparison Between Allergists Versus Nonallergists in Low-Risk Penicillin Allergy Delabeling: Effectiveness, Safety, and Quality of Life (HK-DADI2).

BACKGROUND: Penicillin "allergy" labels are prevalent but frequently misdiagnosed. Mislabelled allergies are associated with adverse outcomes and increased antimicrobial resistance. With an urgent need to delabel the overwhelming number of mislabeled allergies, nonallergist evaluations have been advocated for low-risk individuals. Despite growing interest in non-allergist-led initiatives, evidence on their effectiveness, safety, and impact by direct comparisons is lacking. OBJECTIVE: To assess the comparative outcomes of penicillin allergy evaluations conducted by allergists versus nonallergists. METHODS: A prospective, multicenter, pragmatic study was conducted at 4 tertiary hospitals (1 allergist- vs 3 non-allergist-led) for low-risk penicillin allergy patients in Hong Kong-the Hong Kong Drug Allergy Delabelling Initiative 2 (HK-DADI2). RESULTS: Among 228 low-risk patients who underwent testing (32.9% by allergists, 67.1% by nonallergists), only 14 (6.1%) had positive penicillin allergy testing results. Delabeling rates (94.1% vs 93.3%; P = .777), positive skin test results (2.6% vs 2.7%; P > .99), and drug provocation test results (3.3% vs 2.7%; P = 1.000) were similar between allergists and nonallergists. There were no systemic reactions in either cohort. All patients had significant improvements in health-related quality of life (Drug Hypersensitivity Quality of Life Questionnaire scores -5.00 vs -8.33; P = .072). Nonallergist evaluations had shorter waiting times (0.57 vs 15.7 months; P < .001), whereas allergists required fewer consultations with higher rate of completing evaluations within a single visit (odds ratio, 0.04; P < .001). CONCLUSIONS: With training and support, nonallergists can independently evaluate low-risk penicillin allergies. Compared with allergists, evaluation of low-risk penicillin allergy by nonallergists can be comparably effective, safe, and impactful on quality of life. More multidisciplinary partnerships to empower nonallergists to conduct allergy evaluations should be encouraged.

Validation of the Chinese drug hypersensitivity quality of life questionnaire: Role of delabeling.

The Drug Hypersensitivity Quality of Life Questionnaire (DrHy-Q) is not currently available in Chinese. Besides, penicillin allergy (PA) is a worldwide public health challenge, and delabeling inauthentic PA can improve clinical and economic outcomes. However, its effect on health-related quality of life (HRQoL) remains poorly known. Objective: The study objective is to translate and validate a Chinese version of DrHy-Q and investigate the effect of PA delabeling on HRQoL using DrHy-Q. Methods: A Chinese DrHy-Q was translated then completed by patients with drug allergy labels for psychometric validation. Afterwards, another cohort of patients finished the Chinese DrHy-Q before and after their PA workup for pre-post comparison. Results: A total of 130 patients were studied. Sixty-three patients (79.4% female; median age = 59 ± 15 years) completed the Chinese DrHy-Q for validation (mean score = 38.9 ± 23.5). It demonstrated excellent internal consistency (Cronbach α = 0.956; 95% confidence interval [CI], 0.939-0.971) and test-retest reliability (intraclass correlation coefficient = 0.993 [95% CI, 0.969-0.998]). Construct validity was confirmed by its one-dimensional structure in factor analysis. Divergent validity was established because only 2 (out of 9) SF-36 scales showed weak negative correlations to DrHy-Q. Patients with multiple implicated drugs presented significantly higher DrHy-Q scores than those with only a single drug (42.0 ± 22.5 vs 28.7 ± 24.4; P = 0.038), showing discriminant validity. Subsequently, another 67 patients (73.1% female; median age = 56 ± 15 years) underwent PA investigations and completed their pre-post DrHy-Q. A significant drop in DrHy-Q score was shown (40.8 ± 21.7 vs 26.6 ± 22.5; Cohen's d = 0.964; P < 0.001), reflecting improvement in HRQoL. Conclusion: The Chinese DrHy-Q is reliable and valid for HRQoL assessment. PA delabeling significantly benefits patients' HRQoL. Future larger-scale studies are warranted to corroborate our findings.

Epidemiology, outcomes, and disproportionate burden of food-dependent exercise-induced anaphylaxis from the Hong Kong Multidisciplinary Anaphylaxis Management Initiative (HK-MAMI).

Background: Anaphylaxis is a life-threatening allergic reaction that poses a considerable burden on populations across all ethnicities and age groups. The Hong Kong Multidisciplinary Anaphylaxis Management Initiative (HK-MAMI) was established to streamline the assessment of patients with anaphylaxis via a multidisciplinary and protocol-driven approach. Objective: This prospective study aims to define the etiology, clinical manifestations, and treatment of patients with anaphylaxis in Hong Kong. Methods: Prospective clinical data from allergologic investigations from patients who completed evaluation by the HK-MAMI pathway between January 2017 and August 2022 were analyzed. Results: Of the 161 patients referred via the HK-MAMI, 131 (81.4%) met the diagnostic criteria for anaphylaxis. The median delay in diagnosis was 2 years (range 0-30 years). The majority of anaphylaxis cases were attributed to food-dependent exercise-induced anaphylaxis (FDEIA), especially wheat-dependent exercise-induced anaphylaxis. In acute management settings, paired tryptase samples were taken in only around one-third of anaphylaxis cases, with 82.5% of the samples demonstrating significant elevation. There was a general underprescription of adrenaline autoinjectors, especially for food-related anaphylaxis. Patients with FDEIA had later ages of onset and diagnosis, and they presented with more cardiovascular manifestations. Skin prick tests and specific IgE level tests were able to diagnose 95% of FDEIA cases. Conclusion: Our study highlights the significant burden of FDEIA, and especially WDEIA, in Hong Kong, its association with severe presentations, and difficulties encountered in emergency or primary care settings. We advocate appropriate adrenaline use during acute-care management and discharge plans, as well as taking serum mast cell tryptase samples during acute episodes. Interdisciplinary collaboration remains crucial to upholding proper and optimized care for patients with anaphylaxis in Hong Kong.

Differences in beta-lactam and penicillin allergy: Beyond the West and focusing on Asia-Pacific.

Beta-lactam (BL) antibiotic "allergy" labels are common, but often overdiagnosed. Although much research has been focused on the BL allergy and the delabelling process in the West, studies from other parts of the world remain sparse. This review outlines the contrasting global epidemiology, shifting clinical practices and disparities of BL allergy in the Asia-Pacific region compared with the West. Innovative strategies to overcome barriers in BL allergy workup are discussed and potential directions for future research and service development are also proposed.