Drug Allergy in Children: Adverse Reactions after Skin Testing.

INTRODUCTION: Skin tests are one of the most widely used diagnostic tools for suspected drug allergies in children. Studies on systemic reactions occurring during skin testing with allergens have mostly been conducted in pediatric and adult patient groups together. However, data on adverse reactions including allergic reactions after drug skin tests in children are scarce. It is aimed to determine the adverse reactions after skin test in children with suspected drug allergy. METHODS: Patients who underwent a drug skin test due to the suspicion of drug allergy between May 2017 and June 2020 were evaluated, retrospectively. Data about adverse reactions seen after skin testing at the testing area in the clinic were analyzed. RESULTS: The study included 1,073 children (585 [54.5%] boys and 488 [45.5%] girls) with a median age of 7.5 years. A total of 12 (1.1%) reactions were detected after skin testing, and 4 (0.4%) of them were allergic reactions. Of the allergic reactions, three were anaphylaxis and one was urticaria. Two of the reactions (1 anaphylaxis and 1 urticaria) were detected after the skin prick test and the remaining 2 were detected after intradermal test. Three of the nonallergic reactions were considered as vasovagal reactions and seven were considered as nonspecific and anxiety-related reactions. CONCLUSION: Although drug skin tests were generally well-tolerated and adverse reactions were rare, severe allergic reactions including anaphylaxis may ensue. Skin tests should be necessarily performed in clinical settings in experienced centers.

A New Approach to Eliminate Hymenoptera Venom Grading Sensitization Test in the North Iran: Cross-Sectional Study.

Background: Anaphylaxis is an allergic reaction which occurs with or without the stimulation of the immune system. Hymenoptera stings are common causes of anaphylaxis in the world. Skin tests are the first-line diagnostic measure for Hymenoptera anaphylaxis. The present study aimed to evaluate the safety of a single-step approach in sensitization testing for Hymenoptera venom. Methods: This cross-sectional study was conducted in 2019 in Golestan province the north of Iran. The sample population consisted of 140,000 individuals covered by 84 rural healthcare centers in the vicinity of Gorgan, Iran. Thirty-three patients agreed to receive the diagnostic test. In this research, in contrast to the 2011 ACAAI guideline, the extracts of venom of three types of Hymenoptera were injected intra-dermally without any dilution at the concentration of 1 µg/ml. Results: The results of the skin test in the patients bitten by honey bee, yellow jacket, and paper wasp were negative in 15.2%, 15.2%, and 21.2% of the cases, respectively. After the test, no allergic reaction was observed, with the exception of a minor skin reaction, which improved within a short time. These preventive measures were taken during the test for the following four hours when the patient was present at the test site and up to 48 hours afterward via follow-up from the healthcare center to the home of the patient. Conclusion: The results of our study showed that the non-diluted single injection of the Hymenoptera sting was accompanied by no side effects.

Beta-lactam hypersensitivity in children: Frequency and risk factors.

AIMS: To determine the frequency of an authentic ß-lactam (BL) hypersensitivity (HS) amongst a large number of children and to identify clinical risk factors that predict this hypersensitivity. METHODS: All children with suspected BL allergy were evaluated by skin tests (ST) with the suspected BL. A 1-day oral provocation test (OPT) was performed in children with negative ST. We defined an authentic BL-HS case if the child exhibited a positive ST or a positive OPT. Risk factors associated with BL-HS were assessed using a univariate analysis. Covariates showing a P-value <.2 were included in the multivariate logistic regression analysis to determine independent predictors. RESULTS: A total of 354 patients reporting 368 suspected BL reactions were included. The diagnosis of BL-HS was established in 24 children (6.7%). All these children had a positive ST. OPT was performed in 30 patients and was negative in all of them. In 110 children with a negative ST, BL was tolerated. In the risk factors analysis, 164 children were included. Older age (>5 years) at the reaction (odds ratio = 1.11; 95% confidence interval, 1.01-1.22; P = .02) and BL administered (odds ratio = 7.7; 95% confidence interval, 2.76-21.8; P < .001) were significantly associated with authentic BL-HS. CONCLUSION: BL-HS should be evaluated with an appropriate allergy work-up before strict prohibition is made. In addition, age of patient and BL involved can be used as predictive factors of developing BL-HS in this population.

Management of Patients with Suspected or Confirmed Antibiotic Allergy: Executive Summary of Guidelines from the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC), the Spanish Society of Allergy and Clinical Immunology (SEAIC), the Spanish Society of Hospital Pharmacy (SEFH) and the Spanish Society of Intensive Medicine and Coronary Care Units (SEMICYUC).

Suspected or confirmed antibiotic allergy is a frequent clinical circumstance that influences antimicrobial prescription and often leads to the avoidable use of less efficacious and/or more toxic or costly drugs than first-line antimicrobials. Optimizing antimicrobial therapy in patients with antibiotic allergy labels has become one of the priorities of antimicrobial stewardship programs in several countries. These guidelines aim to make recommendations for the systematic approach to patients with suspected or confirmed antibiotic allergy based on current evidence. An expert panel (11 members of various scientific societies) formulated questions about the management of patients with suspected or confirmed antibiotic allergy. A systematic literature review was performed by a medical librarian. The questions were distributed among panel members who selected the most relevant references, summarized the evidence, and formulated graded recommendations when possible. The answers to all the questions were finally reviewed by all panel members. A systematic approach to patients with suspected or confirmed antibiotic allergy was recommended to improve antibiotic selection and, consequently, clinical outcomes. A clinically oriented, 3-category risk-stratification strategy was recommended for patients with suspected antibiotic allergy. Complementary assessments should consider both clinical risk category and preferred antibiotic agent. Empirical therapy recommendations for the most relevant clinical syndromes in patients with suspected or confirmed ß-lactam allergy were formulated, as were recommendations on the implementation and monitoring of the impact of the guidelines. Antimicrobial stewardship programs and allergists should design and implement activities that facilitate the most appropriate use of antibiotics in these patients.

Drug reaction with eosinophilia and systemic symptoms in a paediatric population: Interest of skin tests.

BACKGROUND: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe adverse drug reaction. It is uncommon in the paediatric population and can be difficult to diagnose as its initial symptoms may mimic a viral infection. OBJECTIVE: To analyse the features of paediatric DRESS and to evaluate the interest of skin tests in identifying the causative drugs. METHODS: It is a retrospective analysis (2004-2021) of DRESS cases diagnosed in paediatric patients. The DRESS diagnosis was defined using the RegiSCAR scoring. The skin tests were performed according to the ENDA recommendations. RESULTS: We included 19 cases of DRESS occurred in 18 patients. Common clinical symptoms were exanthema and fever in 94.7% of cases each. The most commonly affected organ was the liver (84.2%). Among the implicated drugs, 16 were tested and skin tests were positive in 75%. To assess cross-reactivity and co-sensitization, skin tests with related and/or co-administered drugs were performed in eight patients. Among them, only one child had positive results. CONCLUSION: Early diagnosis of DRESS and discontinuation of the incriminated drug might reduce the incidence of mortality in the paediatric population. Skin tests could be a safe and useful tool to identify the causative drug and assess cross-reactivity.

Delayed hypersensitivity reactions to iodinated contrast media: A diagnostic approach by skin tests.

BACKGROUND: Adverse drug reactions to iodinated contrast media (ICM) have risen due to their increasing use in x-ray-based imaging modalities. Delayed hypersensitivity reactions are mainly caused by nonionic monomeric compounds and represent an issue impacting the diagnostic-therapeutic pathways of cancer, cardiology and surgery patients. OBJECTIVES: To prospectively evaluate the usefulness of skin tests in delayed hypersensitivity reactions to ICM and to evaluate the tolerability of iobitridol, a monomeric nonionic low osmolality compound, as a possible safe alternative. METHODS: Patients with delayed hypersensitivity reactions to ICM referred to us from 2020 to 2022 were prospectively enrolled in the study. All patients underwent patch test and, if negative, intradermal test with the culprit ICM and iobitridol as alternative. RESULTS: A total of 37 patients (females 24, 64.9%) were enrolled in the study. Iodixanol and iomeprol were the most frequently involved ICM (48.5% and 35.2%, respectively); 62.2% of patients presented maculopapular eruption, while 37.8% reported delayed urticaria-like rash. Skin tests resulted positive to the culprit ICM in 19 patients (51.4%), 16 to patch test and 3 to intradermal test. Skin tests with iobitridol, tested as alternative, resulted positive in 3/19 patients (15.8%). All 16 patients with negative results to iobitridol were administered this ICM and tolerated it. CONCLUSIONS: In at least half of patients, delayed-type hypersensitivity was demonstrated by skin tests, particularly by patch test. This diagnostic approach resulted simple, cost-effective and safe, not only to confirm the culprit ICM but also to identify iobitridol as feasible alternative.

[How I explore an hypersensitivity to iodinated contrast media]. / Comment j'explore... une hypersensibilité aux produits de contraste iodés.

Immediate or delayed hypersensitivity reactions to iodinated contrast media (ICM) occur in 0.5-3 % of patients receiving radiological examinations using the last generation ICM. Although the majority of the reactions are mild to moderate, severe and potentially lethal reactions may occasionally be observed. In the last few years, there has been an increase of patients referred to the dermato-allergology department for the work-up of a hypersensitivity reaction to ICM. In this article, the allergological investigations and their indications are described in the case of a suspicion of ICM hypersensitivity.

Les réactions d'hypersensibilités immédiates ou retardées aux produits de contraste iodés (PCI) surviennent chez 0,5-3 % des patients bénéficiant d'un examen d'imagerie radiologique utilisant les PCI de dernière génération. Bien que la plupart des réactions soient d'intensité faible à modérée, des réactions sévères, parfois mortelles, sont possibles. Depuis quelques années, on note une nette augmentation du nombre de patients adressés en consultation de dermato-allergologie pour mise au point de réaction d'hypersensibilité aux PCI. Dans cet article, l'exploration allergologique devant une suspicion d'hypersensibilité aux PCI est décrite avec ses indications.

New diagnostic perspectives in the management of pediatric beta-lactam allergy.

Since overdiagnosis of beta-lactam (BL) allergy is common in the pediatric population, delabeling is a critical part of antimicrobial stewardship. Undesirable consequences of inaccurate BL allergy labeling can be handled by incorporating traditional delabeling or newer risk-based strategies into antibiotic stewardship programs. Conventional assessment of BL allergy relies upon a stepwise algorithm including a clinical history with skin testing followed by drug provocation tests (DPTs). However, a growing number of studies highlighted the suboptimal diagnostic value of skin testing in children. Recently, there has been a paradigm shift in the practice of BL allergy assessment due to recent challenging data which emphasize the safety and accuracy of direct DPTs in children with a suspicion of non-immediate mild cutaneous reactions such as maculopapular eruption, delayed urticaria, and possibly also for benign immediate reactions such as urticaria/angioedema. Identifying low-risk BL allergy patients, in whom skin tests can be skipped and proceeding directly to DPTs could be safe, has become a hot topic in recent years. New risk stratification and predictive modeling studies that have the potential to better predict BL allergy risk status have recently been introduced into the field of drug allergy, particularly in adults. However, in contrast to adults, risk assessment studies in children are rare, and optimal risk definitions are controversial. In the coming years, promising potential methods to elucidate the predictors of BL allergy in children will require multidimensional approaches that may include predictive analytics, artificial intelligence techniques, and point-of-care clinical decision tools.

DRESS characteristics according to the causative medication.

BACKGROUND: To date, no study has identified a clear relationship between drug and a specific clinical presentation of DRESS. OBJECTIVES: To investigate the particularities of DRESS and analyze the variation of DRESS pattern according to culprit drugs. METHODS: We analyzed cases of DRESS notified to the Department of Clinical Pharmacology at the University Hospital of Monastir over a 15-year period. The statistical study was performed using the comparative and multivariate analysis. RESULTS: DRESS was mostly induced by anticonvulsive agents (27%) followed by allopurinol (26.3%) and antibiotics (24%): For anticonvulsive agents, the occurrence of lymphadenopathy was higher, renal involvement was rare and mild, and positive skin tests were more frequent. The allopurinol group was associated with the patient's older age and a lower incidence of lymphadenopathy and kidney injury. For antibiotics, eosinophilia rate was lower, time to recovery was shorter, and RegiSCAR score was low. The multivariate analysis showed a link of allopurinol with severe renal impairment, antibiotics with short latency period and low RegiSCAR score, and anticonvulsants with high propensity of positive skin test. CONCLUSION: We report the largest African and south Mediterranean cohort of DRESS and evaluated the usefulness of skin tests in identifying the culprit drug. The prominent finding was that latency period and renal involvement may independently differ according to culprit drugs.

Comparative Assessment of Platinum Salts and Taxane Group Hypersensitivity Reactions, The Role of Skin Tests in Diagnosis?

PURPOSE: We aimed to investigate the role of skin tests (ST) in the diagnosis of hypersensitivity reactions (HSRs) with platinum salts (PS) and taxane (TX) groups drugs and their reliability in patient management. MATERIALS AND METHOD: Patients' data who developed immediate HSR with PS and TX were recorded and ST was performed. The gradual challenge was applied to all patients with ST negative and grade 1-2 with the suspect drug. RESULTS: In total, the data of 104 patients (74 with PS, 30 with TX) who developed HSR against PS and TX were shared. The gradual challenge was applied to 72 ST negative and grade 1-2 patients (46 PS group, 26 TX group). The gradual challenge was negative in 39 patients in the PS group and 23 patients in the Tx group. The negative predictive value (NPV) for PS was 83% and NPV for TX was 88%. We found significantly higher skin test positivity in patients with PS and TX and grade 3 HSR (p = 0.007, p = 0.001). A significant correlation was found between skin test positivity and early onset of symptoms (p = 0.001 for PS, p = 0.015 for TX). In terms of symptoms witnessed in HSR, we observed the itching, urticaria, hypotension, syncope, and abdominal pain symptoms significantly more in the group with a positive skin test (p < 0.024, p < 0.001, p < 0.001, p < 0.002, and p < 0.025, respectively). CONCLUSIONS: We found very high NPV values for PS and TX. We found that the gradual challenge applied to patients with negative skin tests is reliable if Grade 3 HSR is not observed and with this approach, unnecessary desensitization processes and/or drug alterations can be avoided.

Preparations of exploration of immediate hypersensitivity to antineoplastic agents: An oncology pharmacy perspective.

BACKGROUND: Cancer patients are being exposed to antineoplastic drugs more frequently and for longer periods, resulting in a higher risk of hypersensitivity reactions. The aim of this study was to assess the pharmaceutical time and direct cost of drug allergy explorations following immediate hypersensitivity reactions to antineoplastic agents. METHODS: A micro-costing method was used to collect data on consumption of human and material resources for allergy exploration preparations. The monetisation was carried out on the basis of prices and hourly wage costs applied in 2018. The number and type of allergy explorations prepared by the pharmacy as well as nature of antineoplastic drugs tested, and the number of culprit drugs reintroductions were collected. RESULTS: Almost 1.5 h is required to realise allergy tests for one patient including pharmacist time for prescription analysis and pharmacy technician's time for tests preparation. The mean manufacturing cost of these tests is estimated at €62.87 (€57.82-65.49) per culprit drug for one patient. Programming patients according to culprit drugs tested allows rationalising healthcare provider time and increasing efficiency. From January 2010 to December 2018, 277 patients were tested and 490 allergy explorations were performed, corresponding to more than 5000 preparations. Mostly, the culprit drug could be reintroduced (n = 383, 78.2%) allowing patients to receive the best possible treatment. CONCLUSION: Management of hypersensitivity reactions is constantly progressing, as it contributes to improving patient care in oncology. This activity is time-consuming for the pharmacy team but allows patients with previous hypersensitivity reaction to continue effective treatment.

Skin tests in the work-up of cutaneous adverse drug reactions: A review and update.

Skin tests, including patch tests (PTs), prick tests, and intradermal tests (IDTs), are useful in identifying the culprits of cutaneous adverse drug reactions (CADRs), and determining safer, alternative drugs. PTs have a low sensitivity but are valuable in investigating maculopapular exanthema (MPE), as well as severe CADR, including toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), and in particular, acute generalized exanthematous pustulosis (AGEP), and drug reaction with eosinophilia and systemic symptoms (DRESS). To ensure their specificity, at least 10 control tests should be performed. Prick tests are mainly used in the evaluation of immediate-type hypersensitivity and can be performed with all drugs, except opiates. IDTs can be used to explore immediate and delayed-type hypersensitivity, if an injectable form of the drug exists. Except for SJS/TEN, IDTs should be performed by injecting 0.02 mL of the drug. We here provide a practical, up-to-date review on the use of these skin tests in the work-up of CADRs. Numerous negative controls for drug PTs, as well as criteria for the immediate and delayed positivity of prick tests and IDT, are included. It should be emphasized that a negative result never excludes the potential responsibility of a drug in a CADR.

Patch tests in nonimmediate cutaneous adverse drug reactions: The importance of late readings on day 4.

BACKGROUND: Patch tests (PTs) with two readings have been used for decades to identify the culprit drug in nonimmediate cutaneous adverse drug reactions (NICADRs), followed more recently by late reading of intradermal tests (IDTs). Some teams tend to perform PTs with only one reading before IDTs or even directly perform IDTs. OBJECTIVES: To evaluate the relevance of a late PT reading on day 4 (D4) in NICADRs. METHODS: We retrospectively selected patients who had a PT for an NICADR between July 2014 and March 2020. RESULTS: During the study period, 328 patients had a PT with available results. Among the 75 positive-PT patients with available data for the two readings, 41 (54.7%) had positive results on D2 and D4 and 34 (45.3%) had negative results on D2 but positive results on D4. No patient had positive results on D2 and negative results on D4. CONCLUSION: This study shows that a D4 reading enhanced the PT-positive results. A positive PT result allows for reducing the number of IDTs, which are more difficult and costly to perform. Our series suggests that a late PT reading at D4 should be performed for exploring NICADRs.

A multidisciplinary approach of outdoor aeroallergen selection for Skin Prick Testing in the geographical area of Greater Istanbul.

SUMMARY: Background. Aeroallergen selection for skin prick testing and the interpretation of results need to be in line with allergenic sources of a specific geographic area. Objective. To identify aeroallergens for a skin test panel for the specific geographical area of Istanbul in a multidisciplinary approach based on aerobiological parameters, cross-reactivity patterns and clinical symptoms. Methods. Aerobiological parameters, cross reactivity patterns and the European Standard Skin Prick Test Panel determined allergen selection. Atopic adult patients (n = 60) compiled a questionnaire and were skin prick tested with 29 aeroallergens. Aerobiological sampling followed the requirements of the European Aerobiology Society. Results were statistically analyzed. Results. 65% of patients had positive skin reactions. Sensitization to at least one grass allergen was 30%. Key grass allergens were timothy grass (Phleum pratense L.) 25.8% and Johnson grass (Sorghum halepense (L.) Pers.) 22.6%; correlations between grass-sensitizations were significant at p (minor) 0.01 and so was the correlation of Pooideae sensitization with symptoms and medication. Sensitization to at least one woody plant was 23%; to ash (Fraxinus excelsior L.) 8.1%; hazelnut (Corylus avellana L.), olive (Olea europaea L.) and mulberry (Morus alba L.) 6.5%; juniper (Juniperus ashei J.Buchholz) 4.8%. Correlations between Fagales allergen sensitizations were significant. Sensitization to at least one weed was 22%, sensitization to dock (Rumex crispus L.) 12.9%, ragweed (Ambrosia artemisiifolia L.), and mugwort (Artemisia vulgaris L.) 4.8%. Sensitization rates correlated significantly with the length of the Main Pollen Season. Conclusions. The European Standard Panel is suitable for the geographical area of Greater Istanbul, if it comprises Johnson grass and ash. Ragweed has become clinically relevant in this region. Mulberry and dock were exclusively associated to polysensitized individuals suggesting pan-allergen involvement.

Accuracy of penicillin allergy diagnostic tests: A systematic review and meta-analysis.

BACKGROUND: Having a penicillin allergy label associates with a higher risk for antibiotic resistance and increased health care use. OBJECTIVE: We sought to assess the accuracy of skin tests and specific IgE quantification in the diagnostic evaluation of patients reporting a penicillin/ß-lactam allergy. METHODS: We performed a systematic review and diagnostic accuracy meta-analysis, searching on MEDLINE, Scopus, and Web of Science. We included studies conducted in patients reporting a penicillin allergy and in whom skin tests and/or specific IgE quantification were performed and compared with drug challenge results. We quantitatively assessed the accuracy of diagnostic tests with bivariate random-effects meta-analyses. Meta-regression and subgroup analyses were performed to explore causes of heterogeneity. Studies' quality was evaluated using QUADAS-2 criteria. RESULTS: We included 105 primary studies, assessing 31,761 participants. Twenty-seven studies were assessed by bivariate meta-analysis. Skin tests had a summary sensitivity of 30.7% (95% CI, 18.9%-45.9%) and a specificity of 96.8% (95% CI, 94.2%-98.3%), with a partial area under the summary receiver-operating characteristic curve of 0.686 (I2 = 38.2%). Similar results were observed for subanalyses restricted to patients reporting nonimmediate maculopapular exanthema or urticaria/angioedema. Specific IgE had a summary sensitivity of 19.3% (95% CI, 12.0%-29.4%) and a specificity of 97.4% (95% CI, 95.2%-98.6%), with a partial area under the summary receiver-operating characteristic curve of 0.420 (I2 = 8.5%). Projected predictive values mainly reflect the low frequency of true penicillin allergy. CONCLUSIONS: Skin tests and specific IgE quantification appear to have low sensitivity and high specificity. Because current evidence is insufficient for assessing the role of these tests in stratifying patients for delabeling, we identified key requirements needed for future studies.

[Аllergic sensitization in children with atopic dermatitis in the first 2 years of life according to the results of skin tests].

Atopic dermatitis (AD) is associated with food allergies (FA), which frequency and structure varies from region. The objective of the research was to determine the structure of FA in children (<2 years) with AD and to analyze age-specific sensitization. Methods. 79 children with AD aged 2-24 months were examined (Russia, Moscow). Skin prick tests (SPT) with food allergens were used to determine sensitization, if necessary additional SPT with aeroallergens were performed. Results. 51.9% of patients had hypersensitivity to at least 1 allergen. Positive SPT for egg were detected in 38.0%, cow's milk - in 27.8%, fish - in 10.1%. Allergy to fish occurred predominantly in the 2nd year of life (35.0% vs 4.8, p=0.02). Soy, peanuts, and nuts were detected in less than 5% of patients. At 2-6 months of age, sensitization was found in 36.4%, and after 6 months in 57.9% (p=0.08). In the group with FA before 6 months of age (n=8), 7 patients were sensitized to egg and 6 to milk. The prevalence of milk and egg allergy did not differ between exclusively breastfed and formula-fed children. Hypersensitivity to allergens was found in 4 of 10 breastfeeding patients, for compared to 3 of 11 exclusive formula-feeding patients (p=0.66). Acute allergic reactions were reported in 6.3% of patients with AD, which was 12.2% of children with FA. Triggers were egg (n=5) and fish (n=4). Anaphylaxis did not occur until 6 months of age. The frequency of severe reactions was about the same in children 1st and 2nd years of age (p=0.64). SPT urticaria size, defined in points (max=4), did not differ between children 2-24 months of age. Egg and nut allergens showed the maximum skin reaction: medians were 3 [2; 4] and 1.5 [0.75; 2.5] points. Milk allergens caused significantly less reaction compared with egg (p<0.01). These differences were absent when comparing reactions to individual milk serum fraction proteins and reactions to egg. Hypersensitivity to non-food allergens was found in 41.5% of children with FA (21.5% of children with AD), mainly sensitization to cat epithelium, birch, house dust and dog epithelium was detected. Conclusion. Sensitization to milk proteins and eggs is the leading since 2 months of age, without differences in relation to the age of the infant and the type of feeding. In all cases of moderate AD, SCT is applicable in children 0-2 years of age, with practically no age restrictions.

Intradermal Testing Identifies 1 in 4 Patients with Nonimmediate Penicillin Allergy.

BACKGROUND: Intradermal testing with delayed reading (IDTdr), used routinely in many centers, may identify delayed reactions to penicillins. However, few studies have compared the results of IDTdr with drug provocation test (DPT). The aim of this study was to examine the proportion of provocation-positive patients testing positive on IDTdr. METHODS: Fifty-seven patients with a positive DPT occurring >2 h after intake of penicillin V, dicloxacillin, pivampicillin, or amoxicillin had an IDTdr with penicillin G, amoxicillin, ampicillin, and dicloxacillin. A control group included 18 patients with negative DPTs with the suspected penicillin. RESULTS: In total 25% (n = 14) of provocation-positive patients tested positive on IDTdr. Among patients with positive IDTdr, 9/14 (64%) versus 11/43 (26%) in the IDTdr negative group (p < 0.05) had required oral steroids to treat skin reactions following DPT. No other differences between IDTdr positive and negative groups were found. No controls had a positive IDTdr. CONCLUSION: Investigating with IDTdr would have identified 25% of patients with a DPT-verified allergy with delayed reactions. It is difficult to target subgroups who will test positive on IDTdr. There were more patients who tested positive on IDT who had received oral steroids after DPT, and this may be an indication that skin reaction severity plays a role in skin testing diagnostics. Further potential predictors for positivity of IDTdr, such as duration of skin symptoms, should be assessed in large studies in order to optimize the investigations of nonimmediate drug allergic reactions.

Betalactam hypersensitivity: The importance of delabelling in primary care.

PATIENTS AND METHODS: An allergy work-up was performed on adult patients with a history of a penicillin allergy seen by primary medical care in Monastir (Tunisia) between July 2016 and February 2018. Patients with negative skin tests were challenged with amoxicillin. Patients who were delabelled were contacted by phone after 6 months to determine outcomes after any therapeutic penicillin-class antibiotic intake. RESULTS: A total of 39 patients were evaluated and 33 (84.6%) were delabelled. Five patients were penicillin skin-test positive and one was oral challenge positive. We succeeded in contacting 33 delabelled patients at 6 months. Twenty-two patients tolerated a subsequent therapeutic course of amoxicillin, eight patients did not retake penicillin due to a lack of therapeutic indication, and three patients refused an indicated penicillin use fearful of another reaction. CONCLUSION: This study highlights the importance of allergy work-up in the diagnosis of beta-lactam hypersensitivity. Most patients were excessively labelled as beta-lactam allergic and this mislabelling could increase healthcare costs and lead to the development of drug resistance by the use of wide-spectrum antibiotics.

Drug hypersensitivity in children: a retrospective analysis of 101 pharmacovigilance reports.

Our objective was to describe and discuss management of recent cases of drug hypersensitivity in children reported in a pharmacovigilance center. Two pediatric allergy units conducted a collaborative retrospective analysis of 101 adverse drug reactions reported to a regional pharmacovigilance center between January 2016 and July 2019. Time lapse between hypersensitivity reaction onset and allergy consultation varied from 1 month to 12 years. Sixty-two patients (61.4%) presented with immediate reactions, 11 (10.9%) with non-immediate reactions, and 28 (27.7%) had reactions impossible to classify through medical interview. Overall, 92 children (91%) were explored for simultaneously administered drugs. All 113 prick tests were negative, and 2 were uncertain. Among 108 intradermal tests, 2 were positive to penicillin and to an iodinated contrast medium, 105 were negative, and 1 was uncertain. Overall, 129 drug provocation tests were proposed. Nine provocation tests among 80 were positive (11.25%): 6 to penicillin, 1 to sulfonamide antibiotics, and 2 to non-steroidal anti-inflammatory drugs; the remaining 71 were negative. No severe reaction was observed during these tests. Finally, drug allergy was only retained in 11 reported cases (10.9%).Conclusion: These pharmacovigilance reports show the difficulty in defining drug allergy in children only by anamnesis, and that explorations, particularly provocation tests, should take place at a reasonable time lapse after drug hypersensitivity reaction onset. What is Known: • True drug allergy is rarely observed in children. • Absence of full workup leads to falsely labeling children as "allergic." What is New: • Short time lapse between hypersensitivity onset and consultation improves classification of pediatric allergy. • Timely allergy consultations are essential, and tests are useful to confirm or exclude pediatric allergy.

Concordance of skin test reactivity between indoor inhalant allergens among children with allergic respiratory disease.

BACKGROUND: In vitro studies have demonstrated cross-reactivity among indoor allergen proteins in children with allergic respiratory diseases. However, there are only few studies evaluating in vivo response. A skin prick test (SPT) with commercial indoor solutions is widely used in clinical practice. We aimed to evaluate SPT agreement in children with allergic respiratory disease between pairs of common indoor allergens. METHODS: We reviewed SPT results of children 2 to 18 years old, diagnosed with respiratory allergic disease. Results from house dust mite (Dermatophagoides farinae, Dermatophagoides pteronyssinus), cockroach (Periplaneta americana, Blatella germanica), cat and dog were collected. Sensitization was defined as ≥ 3 mm in wheal diameter. Kappa coefficient (κ) was used to analyze sensitization concordance for each allergen pair. RESULTS: The charts of 300 children, 187 (62.33%) males, were reviewed. Mean age was 7.43 ± 3.29 years with 183 (61%), 140 (46.67%), 45 (15%), 30 (10%) sensitizations to house dust mite (HDM), cockroach, cat and dog, respectively. Sensitization concordance between HDM and cockroach was moderate: κ = 0.53 (95% CI: 0.42-0.64). Moderate agreement occurred between dog and cat: κ = 0.41 (95%CI: 0.30-0.52). HDM-sensitized children showed poor concordance with both cat κ = 0.17 (95%CI: 0.09-0.24) and dog κ = 0.09 (95%CI: 0.03-0.14). There was also poor concordance between cockroach-sensitized children to cat κ = 0.19 (95%CI; 0.11-0.28) and dog κ = 0.11 (95%CI; 0.04-0.18). CONCLUSION: We demonstrated moderate agreement of SPT response between HDM and cockroach as well as dog and cat. This may be due to cross-reactivity. Component-resolved diagnosis should be considered in children with co-sensitization of these allergen pairs.