Negative Skin Test Research Articles

Double-blinded randomized prospective trial of intranasal capsaicin treatment for nonallergic rhinitis.

Nonallergic rhinitis (NAR) is currently a diagnosis of exclusion with an unclear pathophysiologic mechanism and limited treatment options. In patients diagnosed with NAR based on symptoms, negative skin testing and positive optical rhinometry (ORM), the study's objective was to evaluate the therapeutic action of intranasal capsaicin in the management of rhinitic symptoms and the effect on ORM readings. Patients with a history of NAR underwent screening by a diagnostic intranasal capsaicin challenge with ORM and skin-prick testing. Twenty-two NAR patients were enrolled and randomized to either treatment with 0.1mM capsaicin (n = 11) or placebo (n = 11). Treatment consisted of 5 consecutive intranasal applications separated by 1 hour with follow-up at 4 and 12 weeks. At each visit, subjects underwent intranasal capsaicin challenge with ORM reading and a visual analog scale scoring of rhinitis symptoms. Treatment with intranasal capsaicin resulted in a median change with improvement in total symptom score (TSS) of -5 from baseline vs an increase of 2 with placebo at 4 weeks, which remained significantly different between the groups at 12 weeks (p = 0.03). At 12 weeks posttreatment, 60% of the intervention group vs 80% of placebo-treated patients still met objective criteria for NAR by ORM. Using ORM in the objective diagnosis of NAR, this trial showed that intranasal 0.1mM capsaicin not only improved rhinitic symptoms but also objectively reduced nasal reactivity and nasal congestion with a 40% responder rate at 12 weeks as noted by ORM.

Nurse Practitioner Led Emergency Clinic for Nosocomial Tuberculosis Exposure in a Level 3 NICU.

This article describes the nurse practitioner (NP) led management of a possible nosocomial exposure of tuberculosis (TB) in a level 3 NICU in Toronto, Canada. 26 babies, premature and term, were identified as being at risk and multiple emergency clinics were set up to diagnose possible infection, prescribe window prophylaxis, and monitor for adverse effects to the medication. The NICU NPs were chosen to organize, co-ordinate, and manage these emergency clinics because of their skills in leadership, diagnosing, therapeutic management, and client relationship building. The clinic was able to achieve 100 percent follow up with each at risk baby, from initial assessment through to completion of window prophylaxis with negative tuberculin skin test. Some insight in to the decision making surrounding possible TB outbreak management is provided, and special considerations around therapeutic management specific to this population are discussed. This incident demonstrates how nurse practitioners can be utilized to provide high quality care, across multiple clinical situations, to meet the needs of the health care system.

Investigation of oral atopic diseases: Correlation between geographic tongue and fungiform papillary glossitis

IntroductionThe correlation between oral lesions and atopy is not new, but few studies have investigated the prevalence of mucosal changes in diseases within the atopic spectrum, leading to conflicting data. Some studies found a possible relationship between geographic tongue, transient lingual papillitis and atopic diseases. AimTo investigate the frequency of geographic tongue and fungiform papillary glossitis in patients with atopic diseases, and its correlation with serum IgE levels and skin test results. Material and methodsThe sample was comprised of participants with atopic diseases paired with participants who received negative puncture skin tests. All were submitted to stomatological and medical evaluations, prick test and oral cytopathological. ResultsThe female sex was more numerous in both groups. Mean age was 21 years. A total of 60 diagnoses of atopic diseases were obtained, with allergic rhinitis being the most prevalent. Fungiform papillary glossitis was the most frequent oral lesion in both groups, while geographic tongue was present in 2 cases (2%) in the test group and 2 (2%) in the control group. Atopic patients with fungiform papillary glossitis presented high serum IgE levels. In atopic patients with geographic tongue, the prick test positively identified extracts of Dermatophagoides pteronyssinus (100%) and Dermatophagoides farinae (100%). ConclusionDue to the low frequency of geographic tongue lesions found in the study, it is no possible to conclude if that could be an oral manifestation of atopy. However fungiform papillary glossitis is a common alteration in atopic and non-atopic patients and has a relationship with high IgE serum levels. However, the consolidation of this result requires a larger sample size.

Symmetrical drug-related intertriginous and flexural exanthema: A little-known drug allergy

Symmetrical drug-related intertriginous and flexural exanthema: A little-known drug allergy

Current challenges in molecular diagnostics of insect venom allergy

Abstract Background Advanced component-resolved diagnostics (CRD) in Hymenoptera venom allergy (HVA) has improved the precise description of individual sensitization profiles. However, diagnostic gaps, peptide-based cross-reactivity, early identification of severe reactors and diagnosis of patients with a clear history of sting reactions but negative specific IgE and skin tests, remain challenging. Methods Systematic literature search in PubMed and critical analysis of recently published studies on insect venom allergy diagnostics. Results and discussion CRD has increased the sensitivity of IgE testing and improved the discrimination of primary sensitization from irrelevant cross-reactivity, ultimately providing a better rationale for therapeutic decisions. Despite these major advances, there is still room for improvement in routine HVA diagnostics. Peptide based cross-reactivity among homologous allergens from Vespinae and Polistinae venoms as well as still existing diagnostic gaps are particularly challenging. No marker allergens are currently available to differentiate Vespula and Polistes sensitizations. Several strategies including clinical setting of basophil activation test (BAT) for routine diagnostics, venomic analysis for the identification of novel allergens and characterization of the molecular basis of cross-reactivity could be used to address major limitations and unresolved issues in molecular diagnostics of HVA.

Latent tuberculosis infection in children and adolescents in Russia

BackgroundAfter the breakup of the Soviet Union, the annual incidence of tuberculosis (TB) in children 15–17 years of age increased in the Russian Federation from 16 per 100 000 population in 1992 to 37 per 100 000 in 2009, and new control measures were implemented. MethodsChildren were screened annually for TB exposure with a tuberculin skin test (TST) at age 1–8 years. If positive, they were investigated for active TB. If no active TB was found, they were treated with isoniazid for 4–6 months; they then underwent 6-monthly skin tests (which included two recombinant proteins) until negative and annual skin tests thereafter. From the age of 8 years, the yearly follow-up was performed using the skin test that included two recombinant proteins, either until they became negative, developed active TB, or turned 18 years. ResultsThe annual incidence of TB in Russian children decreased from 19.1 per 100 000 population in 2001 to 8.3 per 100 000 population in 2018. ConclusionsAnnual screening for TB exposure with treatment for latent or active TB has reduced the annual incidence of TB in Russian children aged 15–17 years to 1992 levels.

Ceftriaxone allergy in a pediatric cohort

Ceftriaxone allergy in children is common and in this small cohort we aimed to characterize the demographic and clinical histories of 14 children with reported immediate drug hypersensitivity to ceftriaxone. Data was collected from children presenting to the Montreal Children’s Hospital with suspected ceftriaxone allergy. A standardized questionnaire was completed by the patient’s parents about the suspected allergic reaction. We had a total of 14 children who had history of allergic reaction after receiving ceftriaxone. Among the 14 patients with suspected ceftriaxone allergy,60% were males and median age was 7 (IQR: 2.90,13.13). Among all,12 (85%) underwent skin testing to ceftriaxone including prick tests and intradermal (ID 20mg/ml ).Three patients (25%) had a positive ID test and were instructed to avoid ceftriaxone and 9 patients (75%) had a negative skin test. Among the group with negative skin tests, three (33 %) had a negative challenge to ceftriaxone,4 patients (44%) had a negative oral challenge to cephalosporins but were not interested in ceftriaxone challenge and one patient was instructed to avoid all cephalosporins completely given a history of mild liver disturbance and eosinophilia which was suggestive of DRESS.There was one patient with negative skin testing and a pending IV ceftriaxone challenge. The majority of children in this cohort with a history of immediate hypersensitivity reactions to ceftriaxone had negative skin testing and one-third had a successful challenge to IV ceftriaxone. We aim to extend our cohort to determine factors associated with true ceftriaxone allergy.

Giant pyoderma gangrenosum in a patient with ulcerative colitis

Introduction:Pyoderma gangrenosum (PG) is a phenomenon of cutaneous ulceration with unknown etiology. About half the cases have associated extracutaneous manifestations or associated systemic diseases. The most commonly associated systemic disorders include inflammatory bowel disease (IBD), hematologic malignancies, autoimmune arthritis, and vasculitis. This is a case report about giant PG with ulcerative colitis (UC), which is extremely rare.Case Presentation:A 39-year-old female farmer with UC for the past 3 years presented with multiple painful ulcers, erosion, exudation, and crusting on the right leg for 1 month. A cutaneous examination showed diffusely distributed, multiple, well-defined, deep purulent ulcers on the right medial shank measuring 6 to 20 cm and sporadic worm-eaten ulceration on the right ectocnemial, with severe oozing and erosions. The ulcerations exhibited deep undermined borders, granulated tissue and a black eschar at the base. The right shank and feet were severely swollen, restricting movement. The arteria dorsalis pedis pulse was good, with normal sensation on the skin of the right shank and feet. Laboratory examinations showed a white cell count of 11.8 × 109/L, hemoglobin was 91 g/L, erythrocyte sedimentation rate was 82 mm/h, unelevated procalcitonin, serum C-reactive protein was 131.29 mg/L, and a negative tuberculin skin test. Enteroscopy demonstrated endoscopic evidence of UC. A skin lesion biopsy showed superficial erosion and scarring. Partial epidermal hyperplasia, partial epidermal atrophy and thinning, mild edema of the dermal papill. Most of the middle and lower part of the dermis, showed dense lymphocytes, histiocytes, multinucleated giant cells, and neutrophil infiltration. PG with UC was diagnosed based on clinical manifestations, laboratory examinations and enteroscopy results.Interventions:She was treated with topical applications of povidone iodine and kangfuxin solution twice daily, methylprednisolone sodium succinate 40 mg and compound glycyrrhizin 60 mg via intravenous drip once a day, along with thalidomide 50 mg twice daily. The UC was controlled with mesalazine.Outcomes:She required multiple therapies to achieve PG healing 3 months later. No PG recurrence was observed during the 1-year follow-up.Conclusion:Recognizing the clinical features of PG and its pathogenic nature, ensuring timely management fundamental for preventing severe destruction and deformity, and control of associated diseases are important aspects of treatment. Combination therapy is essential for PG patients with IBD.

Allergy Evaluation of Hypersensitivity to Platinum Salts and Taxanes: A Six-Year Experience

Hypersensitivity reactions (HSRs) to platinum salts (PS) and taxanes (TX) are a challenge to cancer management. Allergy evaluation based on skin tests (ST) and graded challenges can provide a diagnosis of an allergy to a suspected drug and indicate possible treatment with alternative same-class drugs. This study aimed to estimate the negative predictive value of ST in the diagnosis of HSRs to TX and PS. This multicenter study prospectively enrolled patients with a suspected HSR to PS and TX. ST were performed for chemotherapy, drugs of the same pharmacological class, and other agents (latex or cotreatments). For patients with negative ST, a graded challenge was performed by the cancer teams trained in allergy management. A total of 119 consecutive patients were included during a 6-year period. ST results were positive for 58% of the cohort: for TX in 7 patients and for PS in 62 patients. Other agents were responsible for 4.2% of cases. Skin cross-reactivity was 50% for TX and 30% for PS. A graded challenge was performed in 14 patients for TX and in 50 patients for PS. Negative predictive values (NPVs) for ST were 100% for TX and 92% for PS, with NPVs for individuals PS of 100% for cisplatin, 89% for oxaliplatin, and 87% for carboplatin. ST to PS or TX offered a high NPV, making allergy evaluation a key element in the management of patients with cancer. Graded challenges can be safely performed by oncology teams trained in anaphylaxis management.

Impact of negative tuberculin skin test on growth among disadvantaged Bangladeshi children.

Millions of children are suffering from tuberculosis (TB) worldwide and often end-up with fatal outcome especially in resource-poor settings. Tuberculin skin test (TST) is a conventionally used diagnostic test, less sensitive but highly specific for the diagnosis of clinical TB especially in undernourished children. However, we do not have any data on the role of TST positivity among the children who received nutritional intervention. Our aim was to examine the growth differences between TST-positive and TST-negative undernourished children aged 12 to 18 months who received nutritional intervention prospectively for 90 feeding days. Our further aim was to explore the determinants of TST positivity at enrollment. TB screening as one of the secondary causes of malnutrition was performed on 243 stunted [length for age Z score (LAZ) <-2 standard deviations] or at-risk of stunting (LAZ score between <-1 and -2 standard deviations) children in a community-based intervention study designed to improve their growth parameters. Differences of growth between TST-positives (n = 29) and TST-negatives (n = 214) were compared using paired samples t-test and multivariable linear regression from anthropometric data collected before and after nutritional intervention. Multivariable logistic regression was used to find out possible predictors of TST positivity using baseline sociodemographic data. Of the 243 children screened, 29 (11.9%) were TST-positive and 11 (4.5%) had clinically diagnosed pulmonary TB. Statistically significant improvement of LAZ and weight for age Z-score (WAZ) were observed among the TST-negative participants at the end of intervention period (p = 0.03 for LAZ and p = 0.01 for WAZ). However, we did not find any association between TST status and response to nutritional intervention in our multivariable linear regression models. Our study findings demonstrated a positive impact of nutritional intervention on growth parameters among TST-negative participants.

Borderline-Positive Quantiferon in Children.

We systematically retested children with borderline-positive quantiferon (0.35-0.99 IU/mL) during the period 2015-2019. Among 647 tests, 27 (4%) were positive (>0.35 IU/mL). Borderline-positive quantiferon accounted for 10 of 27 (37%) positive tests. When retested, 9 of 10 (90%) were negative. Children younger than 5 years had negative tuberculin skin tests. Thus, we found high test variability in the borderline range and, in some children, high suspicion of false positive tests.

Mastocytosis presenting as insect anaphylaxis: gender differences and natural history.

Currently, there is strong evidence about an association between hymenoptera venom anaphylaxis (HVA) and mastocytosis. This review is focused on the most relevant clinical and biological features of systemic mastocytosis associated with HVA. HVA is a relatively common complication that modifies the natural course of patients with mastocytosis, particularly men with indolent systemic mastocytosis without skin lesions (ISMs-) in whom HVA can be the presenting symptom in up to around one-half of the cases. Patients with ISMs- associated with HVA are typically males with cardiovascular symptoms in the absence of itching, urticaria, and angioedema during anaphylaxis. Noteworthy, ISMs- is characterized by a low bone marrow mast cell load and a low risk for disease progression. Early and more recent studies support that specific venom immunotherapy (VIT) is a well-tolerated and effective treatment in patients with mastocytosis. VIT should be given life-long to all patients with mastocytosis and proven immunoglobulin E (IgE)-mediated HVA. In patients with negative venom skin test and undetectable IgE antibodies, additional studies such as component-based allergy testing might contribute to confirm an IgE-mediated mechanism of anaphylaxis in some cases, thus providing the indication of VIT.

Hypersensitivity reactions to high osmolality Total Parenteral Nutrition: a case report

BackgroundThe full range of allergic reactions to Total Parenteral Nutrition (TPN) remains unknown. Additionally, beyond individual allergens, there may be other factors contributing to TPN hypersensitivity reactions.Case presentationWe present a case of a patient with negative skin testing to common TPN allergens who had recurrent urticarial reactions to TPN. Her skin reactions resolved once TPN was stopped. Following a literature review, we postulated that the reactions could be due to the high osmolality of her TPN. Consequently, lowering her TPN from 2785 to 1928 mOsm/kg and premedicating with cetirizine resulted in resolution of her urticaria.ConclusionsWhen looking at patients who have hypersensitivity reactions to TPN, one must consider that their reactions may be due to factors other than allergens. More studies are needed to clarify the relationship between high osmolality TPN infusions and non-IgE mediated hypersensitivity reactions.

Beta-lactam allergy in Chinese patients and factors predicting genuine allergy

IntroductionBeta-lactams (BL) are the most frequently reported drug allergy, but the vast majority of patients are found not to be genuinely allergic after evaluation. Few studies have investigated the clinical predictors of genuine BL allergy, and the prevalence in hospitalized Chinese patients is unknown. MethodsPatients admitted to a tertiary hospital in Hong Kong (HK) were analyzed to identify the prevalence and factors associated with the presence of BL allergy labels among hospitalized Chinese patients. A combined cohort of patients having completed allergy investigation for suspected BL allergies in the United Kingdom (UK) and HK were analyzed to identify predictors of genuine allergy. ResultsThe prevalence of BL allergy labels in hospitalized HK Chinese was 5%, which was associated with female gender and concomitant non-BL antibiotic allergy labels. The rate of genuine BL allergy patients referred for suspected allergies in the UK and HK cohort was only 14%. History of anaphylaxis and interval of less than a year since the index reaction were independent clinical predictors of genuine BL allergy. The negative predictive value of penicillin skin testing was 90%, confirming the need for drug provocation testing after negative skin testing. There was a high rate of confirmed piperacillin-tazobactam allergy. DiscussionThe estimated true prevalence of genuine BL allergy in hospitalized HK Chinese is around 0.5%. This high rate of BL mislabeling highlights the need for comprehensive allergy evaluation and screening. History of anaphylaxis and duration since the index reaction are important predictors of genuine allergy. Piperacillin-tazobactam allergy may pose a unique challenge in this population with a high prevalence of suspected allergies, surging antibiotic resistance, and lack of testing available.

STUDY OF EXUDATIVE PLEURAL EFFUSION IN THE AGE GROUP OF 15-40 YEARS WITH SPECIAL REFERENCE TO ADENOSINE DEAMINASE AND TUBERCULIN SKIN TEST IN THE DIAGNOSIS OF TUBERCULOUS ETIOLOGY

Background: A tubercular pleural effusion can either be a sequel to a primary infection acquired 3 to 6 month previously or represent reactivation tuberculousis.&#x0D; Two different pathogenic mechanism can lead to tuberculous pleural effusion. By far the more common is the entry of only a few M. tuberculosis into the pleural space; in the presence of specific cell mediated immunity, tubercle bacilli provoke an intense hypersensitivity reaction and outpouring of fluid. Chest radiograph may or may not reveal associated parenchymal involvement. In the second variety, a subpleural caseous focus or cavity rupture into the pleural space and results in a pleural effusion. In this case chest radiograph nearly always shows parenchymal abnormalities.&#x0D; A definitive diagnosis of TBPE can be difficult to make because of the low sensitivity and / or specificity of noninvasive traditional diagnostic tools.&#x0D; In most series of patients with TBPE the result of pleural fluid staining for acid fast bacilli are virtually always negative and pleural fluid cultures are positive for mycobacteria in &lt;35% of cases. Without underlying lung parenchymal lesion sputum examination may be positive in 4% to 11% of patient with TBPE. On the other hand, pleural biopsy specimen will demonstrate granulomatous pleuritis in 50% to 80% of patients.&#x0D; This study was taken whether pleural fluid ADA and tuberculin skin test has any role in the diagnosis of tubercular pleural effusion.&#x0D; Methods and Materials: In the present study 120 cases of exudative pleural effusion in the age group of 15-40 years of varying etiology are taken who attended the pulmonary medicine department of Burdwan Medical College and Hospital.&#x0D; The study was conducted the period of March 2017 to February 2018 apart from relevant history taking a detail clinical examination, full investigation were done to reach a complete and final diagnosis.&#x0D; Result: In our study 120 patient of aged 15-40 years were taken. Different aetiological groups and there frequency as diagnosed by various mean were Tuberculous – 85%, Paraneumonic effusion – 10 %, Malignant effusion – 10%.&#x0D; There was male preponderance in all groups of pleural effusion. History of contact was present in 34 % cases of tuberculous effusion. Sputum for AFB was found 10.78% cases of tuberculous effusion. These patients also had pulmonary lesions. 80.39% cases of tuberculous effusion had pale yellow coloured effusion but 13.72 % cases had haemorrhagic fluid. 66.66% malignant effusion had haemorrhagic fluid and 33.37% of malignant effusion had pale yellow coloured fluid. Pleural fluid for malignant cell was positively 66.67% of malignant effusion. Pleural fluid for Z-N stain detect 1.96% cases tubercle bacilli in TBPE group. Plural biopsy was found positive in 68.18% cases of TBPE and 60% cases of MPE.&#x0D; Pleural fluid ADA level was significantly higher (P&lt;0.001) in patients of tuberculous effusion than non-tuberculous effusion. Taking a cut off value of 70 U/L sensitivity and specificity is 95.09% and 33.33%. But when parapneumonic effusion was excluded, the specificity increases. Lymphocytic pleural effusion below the age group of 40 years with cut off value of ADA &lt;40 U/L can be used as a screening test for malignant effusion.&#x0D; In TBPE tuberculin skin test was positive in 74.50% cases. Taking a cut off value of 10 mm or more induration of tuberculin skin test, "P" value is less than 0.001. Sensitivity and specificity of tuberculin skin test in tuberculous pleural effusion is 74.50% and 50%.&#x0D; If we compare the efficacy of ADA &gt; 70 U/L and tuberculin skin test positivity to diagnose tuberculous pleural effusion the former is superior statistically to the later (P value is less than 0.01) specificity of tuberculin skin test is low because it may be positive with infection with NTM and prior BCG vaccination.&#x0D; Conclusion: Maximum incidence of tuberculous pleural effusion occurs in the age group of 20-30 years. Malignant pleural effusion is less likely below the age group of 30 years.&#x0D; Increased ADA level &gt;70 U/L in pleural fluid is a sensitive, minimally invasive, cost effective, easy method for diagnosis of tuberculous pleural effusion.&#x0D; Lower level of pleural fluid ADA level (&lt;40 U /L) is a sensitive, specific, minimally invasive, cost effective easy method for suspecting malignant effusion. Its value is much more important when younger patients (&lt;40 years of age) present with malignant effusion, especially so when the pleural fluid is also appeared pale yellow. A low ADA level will guide us to look for malignancy in this age group.&#x0D; Tuberculin skin testing with intermediate strength PPD has a high sensitivity in patients with pleural tuberculosis. It was seen negative in 1/3rd cases of TBPE. This negative tuberculin skin test in TBPE may be due to recent tuberculous infection or may be due to sequestration of PPD reactive T-lymphocytes in the pleural space or patient may be anergic. Our study is insufficient to comment this negative result. More precise study need to comment.

Disorganization of spleen compartments and dermatitis in canine visceral leishmaniasis

Canine visceral leishmaniasis is associated with splenic changes that may interfere with the surveillance of blood borne antigens. Dogs with terminal visceral leishmaniasis present with a variety of skin lesions that may reflect a failure of the immune system to cope with infection. In this study, we compare the frequency of dermatitis in dogs from an endemic area of visceral leishmaniasis and take account of the following parameters: presence/absence of laboratory markers of infection and susceptibility to visceral leishmaniasis, and presence/absence of splenic structural changes associated with severe forms of the disease. Dermatitis was present in 48 of 64 (75%) of the animals. Dermatitis was more frequent in animals with positive splenic culture and negative leishmanin skin test (14/15, 93%) than in non-infected controls (P = 0.01). Diffuse dermatitis was present only in animals with evidence of Leishmania infection. Diffuse dermatitis was also more frequent in animals with positive (9/27, 33%) as opposed to negative (3/34, 9%) serology against Leishmania (P = 0.01). Presence of dermatitis correlated with both perisplenitis (P = 0.03) and with an increase in plasma cell density in the splenic tissue (P = 0.02). Diffuse dermatitis also correlated with splenic lymphoid tissue disorganization (P = 0.03) and germinal center atrophy (P < 0.01). The relationship between chronic dermatitis and spleen disorganization suggests an impairment of immune response to deal with skin aggressions in dogs with severe forms of visceral leishmaniasis. It also suggest that skin biopsy can be used in a model to define severity of canine visceral leishmaniasis.

Lymphocyte Transformation Test (LTT) in Allergy to Benznidazole: A Promising Approach.

Benznidazole (Bzn) from the nitroimidazole family and nifurtimox from nitrofurans family, are drugs used as first and second line treatment for acute and chronic phases of Chagas disease (CD). Even though skin reactions are frequent, confirmed allergy to Bzn is rare, and there are few cases reported in the literature. Since CD treatment is very restrained, the possibility of cross-reactivity between members of the same and other pharmacological families highlights the importance of an adequate diagnosis that allows alternative treatments in CD and other diseases. We report a series of 31 patients (69% women) referred to our Allergy unit with suspected hypersensitivity to Bzn, twenty three of them with mild reactions and eight of them with severe reactions. LTT with Bzn was performed in 31 patients and in 8 negative controls. LTT was also performed in 25 and 20 of these patients with nifurtimox and Mtn, respectively. Twenty-one out of thirty-one patients were Bzn prick tested, and all were negative. We obtained 2/19 positive results on patch tests to Bzn. LTT with Bzn was positive in 22/31 patients (Sensitivity 75.9% and specificity 100%). The test was considered positive with a stimulation index ≥2. There was a positive result in 7/25 patients for nifurtimox and in 7/20 patients with Mtn. After negative LTT and skin tests, oral provocation was performed in 4/9 patients, all negative. LTT is a safe test that seems to be more useful than skin tests (prick and patch test), particularly in severe reactions, in confirming delayed hypersensitivity to Bzn and detecting cross reactivity with other imidazoles such as Mtn and reactivity to other drugs like nifurtimox. Tests for these drugs need to be included in the workup of patients with hypersensitivity to Bzn in case they are needed as an alternative treatment for CD or to treat other frequent infectious diseases.

Assessing cross-reactivity to neuromuscular blocking agents by skin and basophil activation tests in patients with neuromuscular blocking agent anaphylaxis

BackgroundFollowing diagnosis of neuromuscular blocking agent (NMBA) anaphylaxis, identifying safe alternatives for subsequent anaesthesia is critical. A patient with anaphylaxis to one NMBA can also have an allergic reaction to other NMBAs (cross-reactivity). Whilst drug provocation testing is standard for identifying or excluding allergy, there is significant risk. In vitro, after an allergen activates basophils, basophils express surface activation markers that can be measured by basophil activation testing (BAT). We compared cross-reactivity between NMBAs assessed by BAT against that by skin testing. MethodsAll patients attending an anaesthetic allergy clinic in Sydney, Australia between May 2017 and July 2018 diagnosed with NMBA anaphylaxis qualified for this study comparing intradermal skin tests and BAT with a panel of NMBAs (rocuronium, vecuronium, pancuronium, suxamethonium, cisatracurium). ResultsOf the 61 patients participating, sensitisation on skin testing and on BAT completely matched in only nine patients (15%). Sensitisation was not in agreement for pancuronium, cisatracurium and rocuronium, but was in agreement for vecuronium and suxamethonium. Nine patients with negative skin tests subsequently tolerated cisatracurium, and one false positive on BAT to cisatracurium was detected. ConclusionsThe utility of BAT in identifying safe NMBAs for subsequent anaesthesia needs further evaluation. BAT detects a different cross-reactivity profile to skin tests. Negative skin testing and BAT might increase confidence in performing drug provocation testing, but this and follow-up of subsequent anaesthesia in our cohort is necessary to determine the clinical significance of BAT sensitisation.

Mild to moderate hypersensitivity reactions to beta-lactams in children: a single-centre retrospective review

ObjectiveBeta-lactam (BL) antibiotics are the most reported drugs in hypersensitivity reactions in children. More than 90% of these children tolerate the suspected drug after diagnostic work-up. Skin tests (STs) show...

Penicillin Allergy Evaluation: A Prospective, Multicenter, Open-Label Evaluation of a Comprehensive Penicillin Skin Test Kit

Ten percent of the population claims an allergy to penicillin, but 90% of these individuals are not allergic. Patients labeled as penicillin-allergic have higher medical costs, longer hospital stays, are more likely to be treated with broad-spectrum antibiotics, and develop drug-resistant bacterial infections. Most penicillin skin test reagents are not approved by the Food and drug Administration or readily available to evaluate patients labeled penicillin-allergic. To determine the negative predictive value (NPV) of the Penicillin Skin Test Kit containing the major allergenic determinant (penicilloyl polylysine), a minor determinant mixture (penicillin G, penicilloate, penilloate), and amoxicillin, produced according to Food and Drug Administration standards. This was a prospective, multicenter, open-label investigation of penicillin skin testing using the Penicillin Skin Test Kit. Skin test-negative subjects were challenged with 250 mg amoxicillin, whereas skin test-positive patients were not challenged. The primary end point was NPV of the Penicillin Skin Test Kit, defined as the percentage of subjects with negative skin test results who did not experience an IgE-dependent reaction within 72 hours of amoxicillin challenge. In total, 455 patients with a history of penicillin allergy underwent skin testing and 63 (13.8%) had 1 or more positive test results; 65% of the positive test results were to the minor determinant mixture and/or amoxicillin alone. In the per protocol group of 373 skin test-negative subjects, 8 developed potential IgE-dependent reactions following oral amoxicillin challenge, translating to an NPV of 97.9% (95% CI, 95.8-99.1; P < .0001). All but 1 of the reactions was mild or moderate, and most subjects who required treatment received only antihistamines. The Penicillin Skin Test Kit, containing all relevant penicillin allergenic determinants, demonstrated very high NPV. Removal of a penicillin allergy label in a large majority of currently mislabeled patients has substantial personal and public health implications.