Predicting Penicillin Allergy: A United States Multicenter Retrospective Study

BACKGROUND

Using the reaction history in logistic regression and machine learning (ML) models to predict penicillin allergy has been reported based on non-US data.

OBJECTIVE

We developed ML positive penicillin allergy testing prediction models from multisite US data.

METHODS

Retrospective data from 4 US-based hospitals were grouped into 4 datasets: enriched training (1:3 case-control matched cohort), enriched testing, nonenriched internal testing, and nonenriched external testing. ML algorithms were used for model development. We determined area under the curve (AUC) and applied the Shapley Additive exPlanations (SHAP) framework to interpret risk drivers.

RESULTS

Of 4777 patients (mean age 60 [standard deviation: 17] years; 68% women, 91% White, and 86% non-Hispanic) evaluated for penicillin allergy labels, 513 (11%) had positive penicillin allergy testing. Model input variables were frequently missing: immediate or delayed onset (71%), signs or symptoms (13%), and treatment (31%). The gradient-boosted model was the strongest model with an AUC of 0.67 (95% confidence interval [CI]: 0.57-0.77), which improved to 0.87 (95% CI: 0.73-1) when only cases with complete data were used. Top SHAP drivers for positive testing were reactions within the last year and reactions requiring medical attention; female sex and reaction of hives/urticaria were also positive drivers.

CONCLUSIONS

An ML prediction model for positive penicillin allergy skin testing using US-based retrospective data did not achieve performance strong enough for acceptance and adoption. The optimal ML prediction model for positive penicillin allergy testing was driven by time since reaction, seek medical attention, female sex, and hives/urticaria.

A US-Based Multicenter Retrospective Report of Perioperative Anaphylaxis, 2010-2021

BACKGROUND

US-based perioperative anaphylaxis (POA) studies are limited to single-center experiences. A recent report found that a serum acute tryptase (sAT) >9.8 ng/mL or mast cell activation (MCA) can predict POA causal agent identification. Urinary mast cell mediator metabolites (uMC) have not been studied in POA.

OBJECTIVE

To analyze the epidemiologic data of POA, to determine if sAT or MCA can predict suspected causal agent identification, and to evaluate uMC utility in POA.

METHODS

This study is a retrospective multicenter review of POA cases that were subcategorized by suspected causal agent identification status. sAT, MCA (defined as sAT >2 + 1.2 × serum baseline tryptase), and uMC (N-methylhistamine [N-MH], 11β-prostaglandin-F2α [11β-PGF2α], leukotriene E4 [LTE4]) were recorded.

RESULTS

Of 100 patients (mean age 52 [standard deviation 17] years, 94% adult, 50% female, 90% White, and 2% Hispanic) with POA, 73% had an sAT available, 41% had MCA, 16% had uMC available, and 50% had an identifiable suspected cause. POA cases with an identifiable suspected cause had a positive MCA status (100% vs 78%; P = .01) compared with POA with an unidentifiable cause. An elevated median sAT did not predict causal agent identification. Positive uMC were not associated with suspected causal agent identification during POA. Patients with positive uMC had a higher median sAT (30 vs 6.45 ng/mL; P = .001) and MCA status (96% vs 12%; P = .001) compared with negative uMC patients. Patients with POA had an elevated acute/baseline uMC ratios: 11β-PGF2α ratio > 1.6, N-MH ratio >1.7, and LTE4 ratio >1.8.

CONCLUSIONS

The presence of MCA in POA is associated with suspected causal agent identification. Positive uMC possibly correlate with a higher sAT level and MCA status but require further study. The authors suggest applying an acute/baseline uMC ratio (11β-PGF2α ratio >1.6, N-MH ratio >1.7, and LTE4 ratio >1.87) in patients with POA for MCA when a tryptase level is inconclusive during POA evaluations.

Perioperative management of mastocytosis

PURPOSE

Patients with mastocytosis have an increased risk of anaphylaxis during surgical procedures with general anesthesia. Therefore, we reviewed the anesthesia course of a large cohort of patients with mastocytosis.

METHODS

We retrospectively reviewed adult and pediatric patients with mastocytosis who underwent surgical procedures with general anesthesia at Mayo Clinic from January 1, 2000, through June 30, 2021. We also included any procedures with general anesthesia that occurred during the 3-year period preceding mastocytosis diagnosis and designated the patients who underwent these procedures as having an unknown diagnosis at the time of their surgical procedure. We analyzed whether patients received chronic antimediator treatment for mastocytosis and/or prophylactic medications before the procedures. We also determined whether medications indicative of mastocytosis-related adverse events were intraoperatively administered.

RESULTS

We identified 113 patients who underwent 219 procedures during the study period; 25 procedures were performed before mastocytosis diagnosis. Of 194 procedures in patients with known mastocytosis, patients received chronic antimediator therapy and/or perioperative prophylactic medications for 178 (91.8%) procedures. Among these procedures, 10 were potentially complicated by mast cell activation, which was inferred from administration of inhaled albuterol (n = 3) or intravenous diphenhydramine (n = 8). In addition, there was only one case of intraoperative anaphylaxis which occurred in a patient who underwent anesthesia before mastocytosis diagnosis and therefore did not receive prophylaxis.

CONCLUSION

Intraoperative anaphylaxis can be the first presenting sign of mastocytosis. Patients with mastocytosis who received chronic antimediator therapy and/or preoperative prophylactic medications had an uneventful surgical course.

Treatment of perioperative anaphylaxis: room for improvement?

Perioperative anaphylaxis is associated with significant morbidity and mortality. Prompt and appropriate treatment is required for optimal outcome. Despite general knowledge of this condition, delays occur in the administration of epinephrine and in particular the use of i.v. route of administration in the perioperative setting. Barriers should be addressed to allow prompt utilisation of i.v. epinephrine in perioperative anaphylaxis.

Perioperative anaphylactic reactions to central venous and pulmonary artery catheters containing chlorhexidine, sulfadiazine, or latex: a historical cohort study

PURPOSE

Central venous catheters (CVCs) and pulmonary artery catheters (PACs) containing chlorhexidine, silver sulfadiazine, or latex can cause perioperative anaphylaxis. We examined the incidence of and outcomes associated with anaphylaxis caused by CVCs/PACs.

METHODS

In a historical cohort study, we retrospectively identified adult patients fitted with CVCs/PACs at the Mayo Clinics in Minnesota, Arizona, and Florida from 1 January 2008 to 1 March 2018. Potential and confirmed cases of perioperative anaphylactic reactions were individually reviewed and classified.

RESULTS

During the study period, 39,505 procedures were performed during which CVCs/PACs were inserted. Of these, 2,937 patients with pre-existing chlorhexidine, sulfonamide (sulfa), and/or latex allergies had CVCs/PACs inserted that contained these substances. Perioperative anaphylaxis, in which CVCs/PACs were the confirmed or potential causative agent, occurred during 53 procedures. Seven patients had a preoperatively reported sulfa or latex allergy; no patients had a preoperative chlorhexidine allergy. Six of the seven patients with reported allergies to sulfa or latex had a CVC/PAC inserted that contained these substances. Twenty-four patients with anaphylaxis had postoperative allergic disease consultation; ten of these (42%) underwent skin testing.

CONCLUSION

Perioperative anaphylactic reactions related to CVCs/PACs containing chlorhexidine, silver sulfadiazine, or latex were rare in this large historical cohort study. We identified 2,937 patients with pre-existing chlorhexidine, sulfa, and/or latex allergies and had CVCs/PACs inserted that contained these substances. Although few cases of perioperative anaphylaxis attributable to these substances were observed in patients with corresponding allergies, the potential for substantial complication exists. Providers should be aware of the potential for these hidden exposures.

Incidence of perioperative hypersensitivity reactions: A single-center, prospective, US cohort experience

Background

A previous study, using administrative data, reported an incidence of perioperative anaphylaxis (POA) of 1:6537 procedures in the United States.

Objective

We sought to determine the incidence of POA in a prospective US cohort.

Methods

Adult participants undergoing a procedure at a single tertiary care center were studied prospectively between April 2018 and January 2022. Subinvestigators recorded vital signs and skin checks preoperatively, 15 minutes into induction, and hourly thereafter until 1 hour into the postoperative period. If participants developed an adverse reaction, additional variables were documented: causal agent(s) exposure, type of nonallergic adverse reaction, Sixth National Audit Project severity score, evidence of mast cell activation by serum acute and baseline tryptase pairing, Allergy consult, and causal agent identification.

Results

Among 939 procedures (mean age, 59.25 ± 14.78 years; 58% females; 87% White), there were 12 (1.3%) cases with an identified adverse reaction. Nine cases were classified as nonhypersensitivity adverse reactions (1%) and 3 as possible hypersensitivity reactions (0.3%); 1 case was classified as suspected perioperative hypersensitivity and 2 as POA (0.2%). Both POA cases were males, had previous procedures, had evidence of mast cell activation, had a Sixth National Audit Project score of 3, and were referred to Allergy for further evaluation. There were 9 participants who developed a nonhypersensitivity adverse reaction: relative overdose of anesthetic (n = 6), transient rash (n = 2), and isolated bronchospasm (n = 1). All transient rashes were observed during undraping protocol.

Conclusions

In our prospective study, the incidence of POA is 1:470 procedures. Our study suggests that the incidence of POA may be higher than previously reported.

The Nonirritating Concentrations of Neuromuscular Blocking Agents and Related Compounds

BACKGROUND

Skin testing (ST) concentrations of neuromuscular blocking agents (NMBAs), NMBA-reversal agents, and the sugammadex-rocuronium inclusion complex (S-R-Cx) vary widely among reports.

OBJECTIVE

To determine maximal ST nonirritant concentrations (NICs) of NMBAs (cisatracurium, rocuronium, succinylcholine, and vecuronium), NMBA-reversal agents (neostigmine and sugammadex), and S-R-Cx in NMBA-tolerant and NMBA-naïve participants.

METHODS

A single-center, prospective study between October 2019 and November 2021 of adult participants with or without a planned surgical procedure. The reference standard was tolerance of medication tested during a procedure (NMBA-tolerant group) before ST. Participants received skin prick testing (SPT) and intradermal test (IDT) injections at 5-7 increasing concentrations of 1 or more medications. All medications were reconstituted according to package insert instructions and diluted with 0.9% saline. A concentration was considered irritant when more than 5% of participants had a positive test per ST positivity criteria (wheal ≥3 mm than initial wheal and associated erythema of the same size or greater than wheal). We also compared our results with current guidelines.

RESULTS

A total of 187 participants (78% NMBA-tolerant) underwent 7812 skin tests. All undiluted SPT concentrations were nonirritant. We found the following maximal IDT NICs (mg/mL): cisatracurium (0.02), rocuronium (0.05), succinylcholine (0.8), vecuronium (0.01), neostigmine (0.2), sugammadex (50), and S-R-Cx (sugammadex 7.14 + rocuronium 2).

CONCLUSION

Our results suggest that SPT may be performed with undiluted stock concentrations. We confirm maximal IDT NICs for cisatracurium and rocuronium. We also propose that currently recommended maximal IDT NICs of succinylcholine, neostigmine, sugammadex, and S-R-Cx could be increased, whereas the maximal IDT NIC of vecuronium could be decreased compared with current guidelines and prior reports.

Perioperative Hypersensitivity Evaluation and Management: A Practical Approach

Perioperative hypersensitivity (POH) is an uncommon, potentially life-threatening event. Identification of POH can be difficult given the lack of familiarity, physiological effects of anesthesia, draping of the patient during surgery, and potential nonimmunological factors contributing to signs and symptoms. Given the unique nature and large number of medications administered in the perioperative setting, evaluation of POH can be challenging. In this paper, we present a practical approach to management with an emphasis on understanding what happens in the operating room, the overlap of signs and symptoms between nonimmunological and immunological reactions, acute management, and subsequent evaluation. In addition, we provide a strategy for further review of an initially negative evaluation and emphasize the importance of establishing management plans for the patient as well as providing recommendations to the medical, anesthesia, and surgical teams for future surgeries. A critical factor for successful management at all points in the process is a close collaboration between the anesthesia and the allergy teams.

Perioperative Anaphylaxis

Perioperative anaphylaxis is a potentially life-threatening and under-recognized event most commonly caused by antibiotics, neuromuscular blocking agents, dyes, latex, and disinfectants. This review provides updates in the epidemiology and pathogenesis of perioperative anaphylaxis, discusses culprit agents, and highlights the tenets of management including a comprehensive allergy evaluation.

Obstetric Anesthetic Management for Parturients with Hereditary Angioedema: A Case Report and Suggested Protocol

Hereditary angioedema (HAE) is a disease manifested by repeated episodes of localized submucosal or subcutaneous edematous episodes, potentially triggered by emotional stress, mechanical trauma, or intake of estrogens. We present our experience managing two parturients with HAE. Multidisciplinary care is essential for planning and executing the specialized care of these patients, and management included extensive planning among obstetric, anesthesiology, and allergy and immunology teams. Pregnancy has been shown to have a variable effect on triggering HAE episodes. First-line treatment includes C1 esterase inhibitor concentrate, which can also be used for prophylaxis in high-risk patients. Neuraxial analgesia is recommended to avoid general anesthesia and was established early in both individuals. Vaginal delivery was well tolerated without need for emergent treatment for angioedema symptoms.

Incidence of and risk factors for perioperative or periprocedural anaphylaxis in the United States from 2005 to 2014

BACKGROUND

The estimated worldwide incidence of perioperative or periprocedural anaphylaxis (PA) is between 1 in 1250 and 1 in 20,000 procedures.

OBJECTIVE

To evaluate the incidence of PA in the United States and compare patient characteristics and underlying risk factors using a large national database.

METHODS

Using deidentified data from the nationwide inpatient sample from 2005 to 2014, we identified cases of PA through the International Classification of Diseases, Ninth Revision, Clinical Modification codes and conducted a retrospective analysis.

RESULTS

Among 35,647,347 surgeries and procedures, there were 5458 (0.015%) PA cases identified. The incidence of PA was 15.3 cases per 100,000 procedures. When compared with controls, PA cases had an increased mortality (3.4% vs 1.4%; P < .001), median length of stay (5 vs 3 days; P < .001), and median hospital cost ($45,155 vs $24,734; P < .001). The age group between 18 and 34 years (odds ratio [OR], 1.34; 95% confidence interval [CI], 1.13-1.58; P < .001) and female sex (OR, 1.40; 95% CI, 1.31-1.49; P < .001) were associated with increased odds of PA. Transplant (OR, 3.35; 95% CI, 2.59-4.34; P < .001), hematologic (OR, 1.63; 95% CI, 1.30-2.05; P < .001), vascular (OR, 1.49; 95% CI, 1.30-1.67; P < .001), and cardiac (OR, 1.47; 95% CI, 1.30-1.67; P < .001) procedures were at increased risk for PA. Several comorbidities were associated with PA including chronic pulmonary disease (OR, 1.41; 95% CI, 1.31-1.51; P < .001).

CONCLUSION

The incidence of PA is 1 in 6531 procedures, with a mortality of 1 in 191,652 procedures. PA has worsening outcomes compared with controls. The risk factors of PA include age, sex, procedure type, and comorbidities.

Management of a surgical patient with a label of penicillin allergy: narrative review and consensus recommendations

Unsubstantiated penicillin-allergy labels are common in surgical patients, and can lead to significant harm through avoidance of best first-line prophylaxis of surgical site infections and increased infection with resistant bacterial strains. Up to 98% of penicillin-allergy labels are incorrect when tested. Because of the scarcity of trained allergists in all healthcare systems, only a minority of surgical patients have the opportunity to undergo testing and de-labelling before surgery. Testing pathways can be modified and shortened in selected patients. A variety of healthcare professionals can, with appropriate training and in collaboration with allergists, provide testing for selected patients. We review how patients might be assessed, the appropriate testing strategies that can be used, and the minimum standards of safe testing.

Severe/uncontrolled asthma and overall survival in atopic patients with eosinophilic granulomatosis with polyangiitis

BACKGROUND

Although asthma, rhinitis/rhinosinusitis and peripheral eosinophilia are present in virtually all patients with eosinophilic granulomatosis with polyangiitis (EGPA), the role of atopy in these patients is not well defined.

OBJECTIVE

To clarify the role of atopy in patients affected with EGPA.

METHODS

Clinical, laboratory and standard spirometry data have been abstracted from medical records. Only patients who underwent skin and/or specific IgE testing for common aeroallergens before the vasculitic phase were included.

RESULTS

Overall, 33.5% (63) of our patients underwent skin and/or specific IgE testing to aeroallergens. Atopy related to aeroallergens was confirmed in 22.3% (two-third of those tested), and was associated with more severe/uncontrolled asthma (p < 0.001), including a greater use of oral glucocorticoids for respiratory manifestations the year before the diagnosis of EGPA (p = 0.013). Atopic patients with EGPA had higher total serum IgE levels and less renal disease at EGPA diagnosis compared to non-atopic patients (p < 0.05). Among atopic patients, the majority had multiple sensitizations (76%); dust mite and grass pollen were the most common respiratory allergens identified. The number of allergens did not correlate with peripheral eosinophilia, total serum IgE, ESR, or measures of airway obstruction (p > 0.05 in all cases). The presence of atopy increased the risk of severe/uncontrolled asthma, but not the risk of severe vasculitis (Five Factor Score≥1). Atopic patients had a better overall survival (p = 0.027).

CONCLUSION

In EGPA, atopy is associated with better prognosis and more severe/uncontrolled asthma manifestations in the year before the development of vasculitis, but not with more severe vasculitis at presentation.

Sulfonamide Drug Allergy

PURPOSE OF REVIEW

We sought to review past and current literature on sulfonamide drug allergy and distill it in a practical manner to assist the clinician, specifically focusing on cross-reactivity and desensitization.

RECENT FINDINGS

There do not appear to be consistent genetic markers to reliably predict features of or the presence hypersensitivity reactions. Recent evidence continues to alleviate early concerns cross-reactivity between sulfonamide antibiotics and non-antibiotics. Sulfonamide drug allergy is frequently encountered by the practicing clinician. For sulfonamide antibiotics, delayed rash is the most common clinical manifestation. There is no current evidence to support avoidance of all non-antibiotic sulfonamides in those with a reported allergy to sulfonamide antibiotics, although certain scenarios require caution. Available evidence supports the cautious reintroduction of sulfonamide antibiotics via desensitization, which is usually well tolerated and should be considered in those with strong indications for trimethoprim-sulfamethoxazole and a reported sulfonamide allergy.

Asthma and Risk of Appendicitis in Children: A Population-Based Case-Control Study

OBJECTIVE

To assess whether asthma is associated with risk of appendicitis in children.

METHODS

We used a population-based case-control study design using a comprehensive medical record review and predetermined criteria for appendicitis and asthma. All children (age younger than 18 years of age) who resided in Olmsted County, Minnesota, and developed appendicitis between 2006 and 2012 were matched to controls (1:1) with regard to birthday, gender, registration date, and index date. Asthma status was ascertained using predetermined criteria. Active (current) asthma was defined as the presence of asthma symptoms or asthma-related events (eg, medication use, clinic visits, emergency department, or hospitalization) within 1 year before the index date. Inactive asthma was defined as subjects without these events. A conditional logistic regression model was used.

RESULTS

Among the 309 appendicitis cases identified, when stratified according to asthma status, active asthma was associated with significantly increased risk of appendicitis compared with inactive asthma (odds ratio [OR] = 2.48; 95% confidence interval [CI], 1.22-5.03) and to no asthma (OR = 1.88; 95% CI, 1.07-3.27; overall P = .035). When controlling for potential confounders such as gender, age, and smoking status, active asthma was associated with a higher odds of developing appendicitis compared with nonasthmatic patients (adjusted OR = 1.75; 95% CI, 0.99-3.11) whereas inactive asthma was not (overall P = .049). Tobacco smoke exposure within 3 months was associated with an increased risk of appendicitis (adjusted OR = 1.66; 95% CI, 1.02-2.69). Among asthma medications, leukotriene receptor antagonists reduced the risk of appendicitis (OR = 0.18; 95% CI, 0.04-0.74).

CONCLUSIONS

Active asthma might be an unrecognized risk factor for appendicitis in children whereas a history of inactive asthma does not pose such risk. Further investigation exploring the underlying mechanisms is warranted.

Urinary Leukotriene E4 to Determine Aspirin Intolerance in Asthma: A Systematic Review and Meta-Analysis

BACKGROUND

Urinary leukotriene E4 (ULTE4) may be a biomarker that distinguishes aspirin-intolerant asthma from other asthma subtypes.

OBJECTIVE

To estimate the diagnostic testing accuracy of ULTE4 as a marker of aspirin intolerance in patients with asthma using previously published studies.

METHODS

We identified relevant clinical studies from a systematic review of English and non-English articles using MEDLINE, EMBASE, and CENTRAL (inception to February 10, 2015). Articles were screened at the abstract and full-text level by 2 independent reviewers. We included previously published studies that analyzed ULTE4 in human subjects with asthma characterized as having or not having aspirin intolerance on the basis of a specified definition: convincing history of aspirin intolerance, positive aspirin challenge, or both as the criterion standard. Individual-level data points from all included studies were obtained and analyzed.

RESULTS

The search strategy identified 867 potential articles, of which 86 were reviewed at the full-text level and 10 met criteria for inclusion. The sensitivity, specificity, positive predictive value, and negative predictive values of ULTE4 to determine aspirin intolerance in subjects with asthma were 0.55, 0.82, 0.75, and 0.66 (Amersham-enzyme immunoassay); 0.76, 0.77, 0.70, and 0.78 (Cayman-enzyme immunoassay); 0.70, 0.81, 0.86, and 0.79 (mass spectrometry); and 0.81,0.79, 0.65, and 0.88 (radioimmunoassay) at optimal thresholds of 192, 510, 167 to 173, and 66 to 69 pg/mg Cr, respectively. The diagnostic odds ratio for each methodology was 6.0, 11.9, 10.5, and 19.1, respectively.

CONCLUSIONS

ULTE4 is a marker for aspirin-intolerant asthma and could potentially be used as a clinical test to identify the risk of aspirin intolerance in subjects with asthma.

Food Allergy: Common Causes, Diagnosis, and Treatment

Food allergy is a growing concern, and recognition of symptoms, knowledge of common food allergens, and management of reactions are important for patients and practitioners. Symptoms of a classic IgE-mediated food allergy vary in severity and can include any combination of laryngeal edema, wheezing, nausea, vomiting, diarrhea, urticaria, angioedema, and hypotension. Many foods can induce an allergic reaction, but the most commonly implicated foods include cow's milk, egg, peanut, tree nut, soy, wheat, fish, and shellfish. Milk and egg allergy generally develop and are outgrown in childhood. Peanut and tree nut allergy can occur during childhood or adulthood, are less likely to be outgrown, and tend to cause more fatal reactions. Given the possibility of life-threatening reactions, it is important to recognize the potential for cross-reactivity among food groups. Diagnosis of food allergy includes skin prick testing, specific serum IgE testing, and oral food challenges. Management is centered on avoidance of allergenic and cross-reacting foods and early recognition and immediate treatment of reactions. Treatment protocols to desensitize patients to food are currently under investigation.

Stepping down inhaled corticosteroids from scheduled to as needed in stable asthma: Systematic review and meta-analysis

BACKGROUND

Many patients with asthma are potentially overtreated, which results in unnecessary cost and unnecessary exposure to drugs that may result in adverse events. Step down helps reduce overtreatment, may mitigate these harms, and is advocated by major guidelines. Unfortunately, data that support step down are sparse.

OBJECTIVES

This systematic review aimed to examine the effect of stepping down from scheduled inhaled corticosteroids (ICS) to as-needed ICS in patients with stable asthma.

METHODS

Several electronic databases were systematically searched in April 2014. Articles were screened independently in duplicate. Studies were required to have at least a 12-week follow-up duration and to have compared stepping down from scheduled ICS to as-needed ICS and maintenance of scheduled ICS. Patients were required to have stable asthma as evidenced by at least 4 weeks without asthma exacerbation before intervention.

RESULTS

A total of 3025 abstracts were retrieved initially, 77 of which were retrieved for full-text screening. Of these, only two articles were found to be eligible for inclusion, both were randomized controlled trials. By using random effects meta-analysis, it was determined that, after a follow-up of 6-10 months, the relative risk of exacerbation of stepping down from scheduled to as-needed ICS was 1.32 (95% confidence interval [CI], 0.81-2.16; p = 0.27, I(2) = 0%). Those who did not step down had more symptom-free days (standard mean difference 0.26 [95% CI, 0.02-0.49; p = 0.03; I(2) = 22%]).

CONCLUSION

There is currently insufficient evidence to associate stepping down from scheduled to as-needed ICS with a change in exacerbations, although it may lead to fewer symptom-free days.

Stepping down from inhaled corticosteroids with leukotriene inhibitors in asthma: a systematic review and meta-analysis

BACKGROUND

The risks of using leukotriene receptor antagonists (LTRA) as part of a strategy for stepping down inhaled corticosteroid (ICS) are not well known.

OBJECTIVE

To estimate the risk of asthma exacerbation in individuals with stable asthma who start LTRA when stopping ICS or reducing ICS dose.

METHODS

We identified articles from a systematic review of English and non-English articles by using a number of data bases. We included randomized controlled trials with a stable asthma run-in period of 4 weeks or more and a follow-up period of at least 3 months. We included studies of individuals with stable asthma who stopped ICS and substituted LTRA (versus continuing ICS) and who reduced ICS while starting LTRA (versus placebo).

RESULTS

The search strategy identified 1132 potential articles, of which 52 were reviewed at the full-text level, and four met criteria for inclusion. The single article that met the inclusion criteria for substitution of LTRA for ICS as a step-down strategy found a statistically increased risk of treatment failure of 30.3% for substituting LTRA compared with 20.2% for continuing ICS. The three articles that met the inclusion criteria for comparing LTRA versus placebo in patients with stable asthma who reduce ICS found a modestly decreased risk ratio that favored LTRA of 0.57 (95% confidence interval, 0.36-0.90; I(2) = 0%) in studies that only included individuals >15 years old.

CONCLUSION

Only one study addressed the risk of substitution of LTRA for ICS in stable asthma, which limited any strong conclusions about this step-down strategy.

Successful outpatient graded administration of trimethoprim-sulfamethoxazole in patients without HIV and with a history of sulfonamide adverse drug reaction

BACKGROUND

The outcomes of trimethoprim-sulfamethoxazole (TMP-SMX) desensitization have been widely reported in the HIV literature but less so in the non-HIV literature.

OBJECTIVE

To evaluate the safety and efficacy of graded administration of TMP-SMX in patients without HIV and with a history of TMP-SMX adverse drug reaction (ADR).

METHODS

A retrospective chart review, 2004-2012, of all the patients without HIV seen in the Division of Allergic Diseases and with a history of TMP-SMX ADR who underwent outpatient graded administration of TMP-SMX was conducted. The medical record was reviewed for age, sex, details of the initial ADR to TMP-SMX, an indication for TMP-SMX administration, and outcome. Patients also were contacted by telephone, and medical records were reviewed to determine long-term outcomes.

RESULTS

Seventy-two patients (46 women [64%]; mean [SD] age, 57.7 ± 13.89 years]) were included. The most common patient-reported reactions to TMP-SMX were rash 39 (54%), and hives 9 (13%). TMP-SMX administration was needed for the following indications: prophylaxis (62 [86%]) and treatment of infection (10 [14%]). Forty-three of the patients (60%) underwent a 1-day TMP-SMX administration protocol. Thirty-five of the 43 (81%) underwent a 6-step (90 minutes to 6 hours) protocol and 7 of the 43 (16%) underwent a novel 14-step TMP-SMX protocol. Twenty-nine (40%) underwent a >1-day TMP-SMX administration protocol. Our overall success rate was 90% (mean duration of 11 months). Ninety-eight percent of the patients successfully completed a 1-day graded administration protocol, and 76% successfully completed a >1-day protocol. TMP-SMX was stopped in 8 patients because of the ADR.

CONCLUSION

We report the largest case series of successful outpatient graded administration of TMP-SMX with both 1-day and >1-day protocols, which have shown to be safe and well tolerated in patients without HIV and with a history of sulfonamide ADR.

Outcomes of stepping down asthma medications in a guideline-based pediatric asthma management program

BACKGROUND

Little is known about outcomes after stepping down asthma medications within an asthma management program.

OBJECTIVE

To determine outcomes of stepping down asthma medications in a pediatric asthma management program.

METHODS

We performed a retrospective study of 5- to 18-year-old children with asthma in an integrated primary care practice in the United States. Data were included on participants from March 1, 2009, until December 31, 2011. We first determined whether a child was eligible for step down and next recorded whether a step-down attempt was made and if the attempt was successful. In addition to descriptive statistics for the sample demographics and the outcomes of stepping down, univariate and multivariate analyses were performed to determine predictors of successful asthma medication step-down attempts.

RESULTS

Of the 477 children sampled for this study, 264 (55.3%) had a guideline-eligible opportunity to step down asthma medications. An attempted step down occurred in only 89 (33.7%) of children who had guideline-eligible opportunities. A total of 166 children (34.8%) attempted a step down of asthma medication at least once (including those guideline ineligible to step down). Of children with follow-up, 96 (71.6%) of step-down attempts were successful. Time of year (any season except fall) when the step down was attempted predicted successful step down in univariate and multivariate analysis (odds ratio = 3.81; 95% confidence interval, 1.23-11.85; P = .02). Being guideline eligible for step down predicted successful step down in univariate analysis only (odds ratio = 2.51; 95% confidence interval, 1.16-5.43; P = .02).

CONCLUSION

Our findings from this sample of children participating in an asthma management program suggest that stepping down asthma medication based on National Asthma Education and Prevention Program 3 guidelines is frequently successful.

The risk of asthma exacerbation after stopping low-dose inhaled corticosteroids: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Current asthma guidelines suggest that patients and their providers consider decreasing or stopping controller medications when asthma is stable.

OBJECTIVE

We sought to estimate the risk of asthma exacerbation in patients who stop low-dose inhaled corticosteroids (ICSs) compared with those who continue ICSs in randomized controlled trials.

METHODS

We identified relevant trials from a systematic review of English-language and non-English-language articles using MEDLINE, EMBASE, and CENTRAL (inception to January 21, 2012). Articles were screened at the abstract and full-text level by 2 independent reviewers. We included randomized controlled trials with a stable asthma run-in period of 4 weeks or more, an intervention to stop or continue ICSs, and a follow-up period of at least 3 months. We pooled results using a random-effects meta-analysis.

RESULTS

The search strategy identified 1798 potential articles, of which 172 were reviewed at the full-text level and 7 met the criteria for inclusion. The relative risk for an asthma exacerbation in patients who stopped ICSs compared with those who continued use was 2.35 (95% CI, 1.88-2.92; P < .001; I(2) = 0%), as determined by using data pooled from trials with a mean follow-up of 27 weeks. The pooled absolute risk difference for an asthma exacerbation was 0.23 (95% CI, 0.16-0.30; P < .001; I(2) = 44%). Patients who discontinued ICSs also had a decreased FEV1 of 130 mL (95% CI, 40-210 mL; P = .003; I(2) = 53%), a decreased mean morning peak expiratory flow of 18 L/min (95% CI, 6-29 L/min; P = .004; I(2) = 82%), and an increased mean standardized asthma symptom score of 0.43 SDs (95% CI, 0.28-0.58 SDs; P < .001; I(2) = 0%).

CONCLUSION

Patients with well-controlled asthma who stop regular use of low-dose ICSs have an increased risk of an asthma exacerbation compared with those who continue ICSs.

Pretests or advance organizers for Web-based allergy-immunology medical education? A randomized controlled trial

Web-based modules may facilitate instruction on core topics in allergy and immunology (AI). Pretests (PTs) have been shown to improve learning in Web-based courses, but their effectiveness in comparison with advance organizers (AOs) is unknown. We performed a randomized controlled trial of a Web-based educational intervention for teaching the practical aspects of allergen immunotherapy (AIT). AI Fellows-in-Training were randomly assigned to receive the introduction to the modules in an AO outline (AO group) or as PT questions (PT group). The primary outcome was the difference in posttest scores between groups. The secondary outcome was the difference in PT and posttest scores in the PT group. Thirty participants in the AO group and 35 in the PT group completed the modules and the posttest. The mean (SD) posttest score for the AO group was 74% (14%) compared with 73% (9%) for the PT group, a mean difference of -1% (95% CI, -7%, 5%; p = 0.67). A multivariate analysis controlling for year-in-training and total time spent on the modules revealed virtually identical results. The mean (SD) PT score for the PT group increased from 49 (10%) to 73% (9%), a mean difference of 24% (95% CI, 19%, 28%; p < 0.0001). Introducing Web-based allergy education with PT questions or an AO resulted in similar posttest scores. Posttest scores in the PT group improved significantly compared with PT scores.

How well does patient self-report predict asthma medication possession? Implications for medication reconciliation and adherence assessment

BACKGROUND

Self-report is the most commonly used method for collecting information regarding asthma medication possession and adherence in clinical practice.

OBJECTIVE

To determine the agreement between self-report and pharmacy claims data for asthma medication possession.

METHODS

This is a retrospective study that examined pharmacy claims data 12 months before and after participants completed a structured asthma survey. This study was performed in a sample of health care workers and dependents >17 years old in a large, self-insured Midwestern United States health care center. The main outcome measure was agreement (kappa calculation) between self-report and pharmacy claims data of asthma medication possession.

RESULTS

Self-report of asthma medication use agreed moderately with pharmacy claims data for short-acting albuterol (κ=0.47 ± 0.03), salmeterol (κ=0.79 ± 0.04), and montelukast (κ=0.69 ± 0.03) but only slightly for inhaled corticosteroids (κ=0.18 ± 0.03) and prednisone (κ=0.10 ± 0.03) (n=1050 respondents). Both under self-reporting and over self-reporting were common with inhaled corticosteroids (14.4% and 23.1%, respectively) and varied significantly by specific drug type.

CONCLUSIONS

Self-report moderately agrees with asthma medication possession for most adult asthma patients, though the agreement differs considerably between and within asthma medication classes.

Formulating an effective and efficient written asthma action plan

Written asthma action plans (WAAPs) are recommended by national and international guidelines to help patients recognize and manage asthma exacerbations. Despite this recommendation, many patients with asthma do not have a WAAP. In addition, WAAPs vary widely in their readability and usability. To promote issuance and patient use, the WAAP should clearly define the decision (action) points, expected response, and expected time of response. The WAAP should also be easily integrated into a physician's busy practice. Herein, we describe the key elements of an effective WAAP, including concise, detailed recommendations regarding asthma exacerbation recognition (patient self-monitoring) and treatment.

Flunking asthma? When HEDIS takes the ACT

OBJECTIVE

To test several patient-oriented asthma outcome measures and the Healthcare Effectiveness Data and Information Set (HEDIS) measure of appropriate medication for persistent asthma to determine the most useful quality indicator of asthma care.

DESIGN

Prospective mail survey of adult employees and dependents with asthma.

METHODS

The medical and pharmacy claims of all subjects from 12 months before and after the survey were abstracted. Outcomes measures included the Asthma Control Test (ACT), workday loss, unscheduled healthcare utilization (emergency department and inpatient care), and satisfaction with care.

RESULTS

Although 81% of all responders had wellcontrolled asthma, persistent asthma was uncontrolled in 28%. Only 64.5% received appropriate controller medication. Well-controlled asthma is associated with a high degree of satisfaction, less workday loss, fewer prednisone bursts, and minimal unscheduled healthcare utilization. Except for a reduced incidence of more than 2 oral corticosteroid dispensings (6.4% vs 13.6%, P = .012), compliance with the HEDIS appropriate medication for asthma was not positively associated with any of the patient-centered outcomes studied.

CONCLUSIONS

Asthma control was the most useful patient outcome quality indicator in this study. Compliance with the HEDIS asthma measure in this population was not associated with a better patient-oriented outcome. This finding may be different with different levels of asthma control. The positive association between well-controlled asthma and patient satisfaction, minimal unscheduled healthcare utilization, and low workday loss suggests that asthma control as measured by ACT may be a better performance measure in asthma.

The ABCs of asthma control

The new asthma guidelines have introduced impairment and risk assessments into the management of asthma. Impairment assessment is based on symptom frequency and pulmonary function, whereas risk assessment is based on exacerbation frequency and severity. These 2 measures determine the initial severity of asthma in the untreated patient as well as the degree of control in asthma once treatment has been initiated. The focus on asthma control is important because the attainment of control correlates with a better quality of life and reduction in health care use. We describe 4 easy steps to achieving asthma control in the ambulatory practice setting: (1) a standardized assessment of asthma symptoms using a 5-question assessment tool called the Asthma Control Test, (2) a simple mnemonic that provides a systematic review of the comorbidities and clinical variables that contribute to uncontrolled asthma, (3) directed patient education, and (4) a schedule for ongoing care. Most if not all patients can achieve good control of their asthma with optimal care through an active partnership with their health care professionals.

Preoperative evaluation of patients with history of allergy to penicillin: comparison of 2 models of practice

OBJECTIVE

To study whether allergy consultation and penicillin allergy skin testing affects the selection of antibacterial prophylaxis perioperatively in surgical patients with history of allergy to penicillin (HOAP).

PATIENTS AND METHODS

From January 1 through June 30, 2004, we compared 2 different models of practice at our institution. At the Preoperative Evaluation Clinic (POEC), all patients with HOAP are evaluated by an allergist and undergo skin testing for allergy to penicillin. At other (non-POEC) preoperative evaluation settings (OPES), patients with HOAP do not undergo allergy consultation and penicillin skin testing before surgery. Of the 4889 patients screened at the POEC during the study period, 412 consecutive patients with HOAP were included in the study. Of the 416 patients screened at OPES, 69 consecutive patients with HOAP were studied. Logistic regression was used to assess whether allergy consultation was associated with the choice of antibiotic for antibacterial prophylaxis perioperatively, after adjusting for age, sex, and type of surgery.

RESULTS

Perioperative cephalosporin use was greater among patients screened at POEC vs those screened at OPES (70% vs 39%, P<.001 unadjusted; P=.04 adjusted for age, sex, and type of surgery). Vancomycin use was lower for patients screened at POEC vs those screened at OPES (10% vs 28%, P<.001 unadjusted; P=.03 adjusted).

CONCLUSION

For patients with HOAP, evaluation at the POEC was associated with increased use of cephalosporin and decreased use of vancomycin.

Monoclonal gammopathies and malignancies in patients with chronic urticaria

BACKGROUND

Monoclonal gammopathy of undetermined significance (MGUS) has been described in association with chronic urticaria (CU) in patients with Schnitzler syndrome. Chronic urticaria may be a manifestation of hematologic malignancies.

METHODS

This study was conducted to evaluate the frequency and characteristics of MGUS or malignancy in patients with CU. The Mayo Clinic electronic database was reviewed to identify patients with the diagnosis of CU.

RESULTS

Of the 1639 patients presenting with CU between 1994 and 2001, 797 (49%) underwent laboratory evaluation for the presence of a coexisting monoclonal protein. Forty-seven CU patients had MGUS, 142 had a malignancy, and 24 had both. Fifteen percent of CU patients with MGUS had a hematologic malignancy compared with 0.9% of CU patients without MGUS (P < 0.001). Patients presenting with a new diagnosis of CU at an older age (> 56 years) were more likely to have associated underlying MGUS. The occurrence of MGUS in this group was higher than the reported incidence of MGUS in the general population.

CONCLUSIONS

Patients with CU younger than 43 years were unlikely to have associated MGUS or malignancy. A higher percentage of patients with CU and MGUS had an associated diagnosis of hematologic malignancy.

Effects of (R)- and (S)-isomers of beta-adrenergic agonists on eosinophil response to interleukin-5

BACKGROUND

Racemic beta2-adrenergic receptor agonists (beta2-agonists) are used frequently to treat patients with asthma. Potential differences in the biological activities and clinical efficacies among racemic beta2-agonists and their isomers are controversial, and research into these possible differences is limited.

OBJECTIVE

We hypothesized that the (S)- and the (R)-isomers of beta2-agonists have opposing effects on the activation of inflammatory cells.

METHODS

Isolated human eosinophils were pretreated with 1:1 racemic (R,S)-, (R)- or (S)-albuterol, isobutyl methylxanthine (IBMX), and stimulated with IL-5. The kinetics of superoxide production were examined by reduction of cytochrome c, and the effects of pharmacological agents on superoxide production were monitored for 180 min.

RESULTS

(R,S)-albuterol inhibited IL-5-induced superoxide production. This inhibition was enhanced by a cyclic adenosine monophosphate (cAMP) phosphodiesterase inhibitor, IBMX, and was reversed by the selective beta2-adrenergic receptor antagonist, ICI 118, 551, verifying the involvement of both cAMP and the beta2-adrenergic receptor. In addition, (R)-albuterol alone, similarly to (R,S)-albuterol, significantly inhibited IL-5-induced superoxide production up to 60 min (P<0.05, n=4), but the inhibition was lost with longer incubation. In contrast, (S)-albuterol with IBMX did not inhibit IL-5-induced superoxide production before 60 min, but it significantly enhanced IL-5-mediated superoxide production after 60 min (P<0.05, n=4). When both were present as racemic (R,S)-albuterol, the inhibitory effect of (R)-albuterol was not affected by (S)-albuterol.

CONCLUSION

When incubated with IL-5-activated eosinophils, (R)-albuterol shows anti-inflammatory effects and (S)-albuterol shows pro-inflammatory effects in the presence of IBMX. The kinetics of these effects are different, and when used simultaneously, (R)-albuterol predominates. When marked usage of the (S)-isomer is anticipated, racemic (R,S)-albuterol should be used clinically with caution.

Tongue engorgement with prolonged use of the esophageal-tracheal combitube

We report a case of massive tongue engorgement associated with placement of an esophageal-tracheal twin-lumen airway device (Combitube) in a morbidly obese patient. Approximately 4 hours after atraumatic placement of the Combitube, tongue swelling occurred. An emergency tracheostomy was needed for airway management before removal of the Combitube. Ischemia-reperfusion injury or compression of glossal blood vessels, specifically lingual veins, was the most likely cause for the patient's tongue engorgement. An exhaustive search for other causes revealed nothing. Prolonged use of the Combitube may incur greater risk of airway complications such as tongue engorgement.

Successful progressive challenge after a cutaneous reaction to imatinib mesylate (Gleevec): a case report and review of the literature

The use of imatinib mesylate (Gleevec), a selective tyrosine kinase inhibitor, has become the new gold standard for the treatment of chronic myeloid leukemia. Unfortunately, the medication has been commonly associated with mild to severe cutaneous reactions, which has limited its use for some patients. We describe a case of a successful progressive challenge of a patient with a drug-induced exanthem from imatinib mesylate and a review of the literature.

Clinical evaluation and management of drug hypersensitivity

Adverse drug reactions are a major health problem in the inpatient and outpatient clinical setting. Although all of the immune mechanisms of drug reactions are not well characterized, a detailed medication history, knowledge of the signs and symptoms associated with known immune mechanisms, and knowledge of the types of medications typically associated with distinct immune reactions are helpful in implicating the causative drug. Standardized testing for drug reactions is limited, especially for non-IgE-mediated reactions. Management consists of stopping the offending drug, treating the acute reaction, and making a determination concerning future use of the drug.

Does rhinitis lead to asthma? Evidence for the one-airway hypothesis

The link between upper airway disease (allergic rhinitis) and lower airway disease (asthma) has long been of interest to physicians. Recently, extensive research has established that epidemiologic and therapeutic links exist between allergic rhinitis and asthma. Other recent evidence has provided a better understanding of the pathophysiologic interrelationship between allergic rhinitis and asthma. Such information has had an impact on the management of these disorders, including treatment and prophylaxis.

The incidence of anaphylaxis following intravenous phytonadione (vitamin K1): a 5-year retrospective review

BACKGROUND

Phytonadione (vitamin K1) administered intravenously (i.v.) has been associated with anaphylaxis, although the incidence is not known. The anaphylaxis is thought to be attributable to the solubilizing vehicle, polyethoxylated castor oil (Cremophor EL, BASF AG, Ludwingshafen, Germany).

OBJECTIVE

To estimate the incidence of anaphylaxis after i.v. administration of phytonadione.

METHODS

A retrospective review of anaphylaxis after i.v. phytonadione over a 58-month period at a large academic center was performed. During the period of the study a protocol for the administration of i.v. phytonadione was in place. A review of computerized records and survey of staff identified cases of anaphylaxis meeting predefined inclusion criteria. In addition, a literature review was performed for articles concerning anaphylaxis after i.v. phytonadione.

RESULTS

Over the 58 months of the study, a total of 6,572 doses of i.v. phytonadione were administered. Two cases of anaphylaxis after i.v. phytonadione were identified. The incidence of anaphylaxis was 3 per 10,000 doses with 95% confidence intervals of 0.04 to 11 per 10,000 doses. The literature review identified 14 cases meeting inclusion criteria with no reviews of the literature or estimates of incidence.

CONCLUSIONS

The incidence of anaphylaxis after i.v. phytonadione is overall comparable or slightly less than other drugs known to cause anaphylaxis. We do not recommend routine pretreatment with antihistamines or corticosteroids before administration of phytonadione.

Preventing and managing drug-induced anaphylaxis

Drug-induced anaphylaxis and anaphylactoid reactions have increased in frequency with more widespread use of pharmaceutical agents. Anaphylaxis is a systemic, severe immediate hypersensitivity reaction caused by immunoglobulin (Ig) E-mediated immunological release of mediators of mast cells and basophils. An anaphylactoid reaction is an event similar to anaphylaxis but is not mediated by IgE. The incidence of anaphylactic or anaphylactoid reactions differs amongst classes of medications. Antibacterials are the most usual offenders, and penicillins are the most studied. Other compounds commonly causing reactions include non-steroidal anti-inflammatory drugs, anaesthetics, muscle relaxants, latex and radiocontrast media. Prevention, if possible, is the purpose of detailed patient history taking and physical examination. Simple strategies can be employed to decrease the risk of anaphylaxis. These include consideration of the route of drug administration, identification of patients with known causes of anaphylaxis, and the knowledge that certain medications cross react and are contraindicated in those with known history of anaphylaxis. Tests are available, and include IgE-specific skin tests and radioallergosorbent tests. Penicillins are the only compounds whose antigenic determinants are well documented, it is therefore difficult to determine the negative predictive value of other compounds tested. Oral challenge remains an alternative, though entails risk. Desensitisation procedures, as well as gradual dose escalation protocols, are available and can be implemented based on patient history and diagnostic testing. The management of anaphylaxis is based on control of the airway, breathing and circulation. Treatment consists of epinephrine (adrenaline) and supportive measures. Rapid diagnosis and intervention are important in these life-threatening reactions. After stabilisation, all individuals with a documented history of anaphylaxis require a Medic-Alert bracelet or necklace, and an identification card for their wallet or purse.

Hymenoptera (apid and vespid) allergy: update in diagnosis and management

Allergic reactions to Hymenoptera stings range from large local reactions to life-threatening anaphylaxis. Over the last 20 years, significant progress has been made using venom extracts in the diagnosis and treatment of Hymenoptera allergy. Despite these advances, there is still room for improvement in increasing the sensitivity of venom allergen skin testing. The venom allergic patient with negative skin tests poses special problems in management. It is important to note their increased risk with a subsequent sting. Guidelines to be used in determining the duration of venom immunotherapy are still evolving. Knowledge of the risks of discontinuing venom immunotherapy and risk factors associated with anaphylaxis with subsequent stings are required to form an individualized approach to treatment.

Which diagnostic tests for common allergies? Where to start when you face an allergy puzzle

The picture is all too common. In fact, you probably see it in about 1 of every 10 patients who come through your door. The runny nose, scratchy throat, itchy eyes, recurrent sneezing, and annoying cough all point to an allergy. But where do you start and how far do you go in your search for the cause? In this article, Dr Volcheck describes the most commonly used tests for detecting sensitivity to specific IgE allergens and discusses the clinical usefulness and practicality of the various diagnostic procedures.