Hypersensitivity reactions to non beta-lactam antimicrobial agents, a statement of the WAO special committee on drug allergy

Patch testing in non-immediate hypersensitivity to cotrimoxazole: Is it useful?

BACKGROUND

Existing literature has questioned the sensitivity of patch testing (PT) with cotrimoxazole (CTX) in the study of drug hypersensitivity.

OBJECTIVES

Assess the sensitivity of PT with CTX in non-immediate cutaneous adverse drug reactions (CADR).

PATIENTS/MATERIALS/METHODS

Retrospective analysis (2000-2022) of PT with an antibiotic series including CTX 10% pet (Chemotechnique Diagnostics©) performed according to ESCD guidelines in patients with suspected non-immediate CADR reactions to CTX. Some patients were additionally tested with in-house preparations of CTX from Bactrim DS® tablets at 10% in pet or water and trimethoprim 10% pet (Laboratórios Edol©).

RESULTS

Sixty-four patients (48F/16M; mean age 47 ± 18) were included, mostly with maculopapular exanthema (51, 80%). Notably, CTX was sole suspect in 24 patients. There was no positive reaction to CTX at 10% from Chemotechnique or Bactrim DS® tablets prepared at 10% pet for patch testing. One patient reacted exclusively to trimethoprim with 1+ reaction. Two patients had a faint reaction (1+) only with the powder of Bactrim DS® tablets in water at D2, but as the reactions faded completely in 24 or 48 h, they were interpreted as irritant non-specific reactions.

CONCLUSION

These findings suggest that patch testing may lack sufficient sensitivity to diagnose CTX-induced non-immediate CADR. Therefore, clinicians should be cautious interpreting CTX patch test results.

Phosphatidylserine liposomes induce a phagosome acidification-dependent and ROS-mediated intracellular killing of Mycobacterium abscessus in human macrophages

Mycobacterium abscessus (Mab) is an opportunistic nontuberculous mycobacterium responsible of difficult-to-treat pulmonary infections in vulnerable patients, such as those suffering from Cystic Fibrosis (CF), where it represents a major cause of morbidity and mortality. Additionally, due to the intrinsic extensive antimicrobial resistance spectrum displayed by this species and the side effects reported for some available antibiotics, the therapeutic management of such infections remains extremely difficult. In the present study, we show that phosphatidylserine liposomes (PS-L) enhance intracellular mycobacterial killing of Mab infected human macrophages with functional or pharmacologically inhibited cystic fibrosis conductance regulator (CFTR), by a mechanism involving phagosome acidification and reactive oxygen species (ROS) production. Additionally, PS-L significantly reduce proinflammatory response of Mab infected macrophages in terms of NF-kB activation and TNF-α production, irrespective of CFTR inhibition. Altogether, these results represent the proof of concept for a possible future development of PS-L as a therapeutic strategy against difficult-to-treat Mab infection.

Ibuprofen and Other Arylpropionics: The Relevance in Immediate Hypersensitivity Drug Reactions

BACKGROUND

Ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), is the most frequent medication to be involved in hypersensitivity drug reactions (HDRs). Other analgesic/anti-inflammatory drugs in the arylpropionic group are also relevant, albeit to a lesser extent. Ibuprofen is widely consumed by people of all ages, both on medical prescription and over the counter; moreover, it is an organic contaminant of surface waters and foods. While numerous drugs cause HDR, ibuprofen's underlying mechanisms are more intricate and involve both specific immunological and non-immunological mediated reactions.

SUMMARY

we concentrate on immediate responses, including urticaria with or without angioedema, anaphylaxis, and angioedema, classifying reactions according to whether they are caused by single or multiple NSAIDs and based on the mechanisms at play. Both groups may experience anaphylaxis, defined as an immediate, severe systemic reaction involving at least two organs, though the frequency and severity can vary. Following this classification, more clinical manifestations can be identified. Diagnosis is partly based on a detailed clinical history, including information about ibuprofen and/or other arylpropionic derivatives involved, the interval between drug intake and symptoms onset, clinical manifestations, number of episodes, and the patient's tolerance or response to other medications - mainly non-chemically related NSAID - both before and after reactions to ibuprofen and/or other arylpropionic drugs. A drug provocation test is frequently necessary to make a diagnosis.

KEY MESSAGE

Because ibuprofen is the most widely prescribed NSAID, it is reasonable to assume its role as the leading cause of HDR will only become more important.

Cross-reactivity among and between macrolides, lincosamides, and streptogramins: Study on the French pharmacovigilance database

BACKGROUND

Hypersensitivity reactions (HSR) are reported for the macrolides, lincosamides, and streptogramins (MLS) antibiotic family. Data about cross-reactivity among and between MLS remain scarce or controversial.

OBJECTIVES

The aim of this study was to provide an overview of hypersensitivity cross-reactions among MLSs based on data extracted from the French National Pharmacovigilance Database (FPVD).

METHODS

Cases of HSR to MLSs reported between January 1985 and December 2019 were extracted from the FPVD using standardized MedDRA queries (SMQ). Cases including an allergological test involving multiple MLSs and giving at least one positive result were included.

RESULTS

Of the 8394 cases reviewed, 149 were included. HSR mainly involved pristinamycin (n = 83; 53.2%) and spiramycin (n = 31; 19.9%). HSR to MLS was immediate in 54 cases and delayed in 94 cases. Skin tests represented the majority of the allergological tests performed (n = 728; 84.7%), followed by reintroduction tests (n = 79; 9.2%). Eighty-six cross-reactivities among MLS were identified in 62 cases (41.6%). All the 25 explorations performed for streptogramins showed cross-reactivities, but only 30/253 among macrolides (11.9%). Cross-reactivities between the three MLS were observed in 31/322 (9.6%) of the allergological explorations.

CONCLUSION

This study highlights the possibility of cross-reactivity among and between MLSs. Dermatologists and allergologists managing patients with HSR to MLSs should be aware of a risk of cross-reactivity among the macrolides and between the different classes of MLS and to perform MLSs allergological testing before recommending an alternative antibiotic, especially in severe drug hypersensitivity from the MLS family.

Emphasis on Nanostructured Lipid Carriers in the Ocular Delivery of Antibiotics

BACKGROUND

Drug distribution to the eye is still tricky because of the eye's intricate structure. Systemic delivery, as opposed to more traditional methods like eye drops and ointments, is more effective but higher doses can be harmful.

OBJECTIVE

The use of solid lipid nanoparticles (SLNPs) as a method of drug delivery has been the subject of research since the 1990s. Since SLNPs are derived from naturally occurring lipids, they pose no health risks to the user. To raise the eye's absorption of hydrophilic and lipophilic drugs, SLNs can promote corneal absorption and improve the ocular bioavailability of SLNPs.

METHODS

To address problems related to ocular drug delivery, many forms of nano formulation were developed. Some of the methods developed are, emulsification and ultra-sonication, high-speed stirring and ultra-sonication, thin layer hydration, adapted melt-emulsification, and ultrasonication techniques, hot o/w micro-emulsion techniques, etc. Results: Nanostructured lipid carriers are described in this review in terms of their ocular penetration mechanism, structural characteristic, manufacturing process, characterization, and advantages over other nanocarriers.

CONCLUSION

Recent developments in ocular formulations with nanostructured bases, such as surfacemodified attempts have been made to increase ocular bioavailability in both the anterior and posterior chambers by incorporating cationic chemicals into a wide variety of polymeric systems.

Propylene Glycol Potentiates the Inhibitory Action of CTZ Paste on Antibiotic-Resistant Enterococcus faecalis Isolated from the Root Canal: An In Vitro Study

This study aimed to evaluate if the change of vehicle for CTZ (Chloramphenicol, Tetracycline, zinc oxide, and Eugenol) paste improves the inhibition of Enterococcus faecalis in vitro. The vehicles evaluated alone and mixed with CTZ were Eugenol, propylene glycol (PG), super-oxidized solution (SOS), grapefruit-seed extract (GSE), and 0.9% saline solution as a negative control. A clinical isolate of E. faecalis was morphologically and biochemically characterized, and its antimicrobial susceptibility was tested using 20 antimicrobial agents. Once characterized, the clinical isolate was cultivated to perform the Kirby-Bauer disc diffusion method with paper discs embedded with the different vehicles mixed or used alone, and incubated at 37 °C for 24 h. Data were analyzed using one-way ANOVA, and the means were compared using Tukey test with a significance level of p < 0.05. For vehicles used alone, GSE presented the greatest inhibition showing a statistically significant difference with the rest of the vehicles. When vehicles were mixed with the CTZ paste, PG showed a greater inhibition with a statistically significant difference from the rest of the vehicles. In conclusion, the vehicle used to mix the CTZ paste plays an important role in the inhibition of E. faecalis in vitro; therefore, we consider that this can be an important factor to achieve success in the use of this technique.

Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome in childhood: a narrative review

Despite being rare, the Drug Rash with Eosinophilia and Systemic Symptoms (DRESS) syndrome is a serious, possibly fatal condition that may affect both adults and children who may be also burdened by delayed sequelae. It is an adverse drug reaction characterized by widespread skin involvement, fever, lymphadenopathy, visceral involvement, and laboratory abnormalities (eosinophilia, mononucleosis-like atypical lymphocytes). It is more frequently triggered by anticonvulsants, sulphonamides, or antibiotics, the latter being responsible for up to 30% of pediatric cases. The disease typically develops 2-8 weeks after exposure to the culprit medication, with fever and widespread skin eruption; mild viral prodromes are possible. Unfortunately, diagnosis is challenging due to the absence of a reliable test; however, a score by the European Registry of Severe Cutaneous Adverse Reactions (RegiSCAR) allows to classify suspect patients into no, possible, probable, or definite DRESS cases. Moreover, rapid-onset DRESS syndrome has been described in recent years. It affects children more often than adults and differs from the most common form because it appears ≤15 days vs. >15 days after starting the drug, it is usually triggered by antibiotics or iodinated contrast media rather than by anticonvulsants and has a higher presence of lymphadenopathy. Differential diagnosis between rapid-onset antibiotic-driven DRESS syndrome, viral exanthems, or other drug eruptions may be challenging, but it is mandatory to define it as early as possible to start adequate treatment and monitor possible complications. The present review reports the latest evidence about the diagnosis and treatment of pediatric DRESS syndrome.

The Dutch Working Party on Antibiotic Policy (SWAB) guideline for the approach to suspected antibiotic allergy

OBJECTIVES

Prudent handling of reported antibiotic allergy is an important aspect of antibiotic stewardship. The Dutch Working Party on Antibiotic Policy (SWAB) constituted a multidisciplinary expert committee to provide evidence-based recommendations for bedside decision making in antibiotic therapy in patients that report an antibiotic allergy.

METHODS

The guideline committee generated 12 key questions, most of which were population, intervention, comparison and outcome (PICO) questions relevant for both children and adults with suspected antibiotic allergy. For each question a systematic literature search was performed and reviewed for the best available evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Quality of evidence was graded from very low to high and recommendations were formulated in structured discussions as strong or weak.

RESULTS

Sixty recommendations were provided for suspected allergy to beta-lactam antibiotics (BLA) and non-beta-lactam antibiotics (NBLA). Due to the absence of randomized controlled trials in this field, the underlying evidence was predominantly graded as low or very low. Available data supports that a detailed allergy history should always be performed and critically appraised. When cross-allergy between BLA groups is not to be expected due to absence of molecular similarity of the side chains, the patient can be safely exposed to the alternative BLA. An exception to this rule are severe delayed type reactions, in which reexposure to a BLA should only be considered after consultation of a multidisciplinary team.

CONCLUSIONS

Accumulated scientific data now supports a more liberal approach that better balances benefits of treatment with first choice and usually smaller spectrum antibiotics with appropriate avoidance of antibiotics in case of a truly high risk of a (severe) allergic reaction. In the Netherlands, a formal guideline was developed that provides recommendations for the approach towards suspected allergy to BLA and frequently used NBLA, thereby strongly supporting antimicrobial stewardship.

Immediate and Delayed Hypersensitivity Reactions to Antibiotics: Aminoglycosides, Clindamycin, Linezolid, and Metronidazole

Hypersensitivity reactions including IgE-mediated and delayed cell-mediated reactions to aminoglycosides, clindamycin, linezolid, and metronidazole are rare. For aminoglycosides, allergic contact dermatitis is the most frequent reaction for which patch testing can be a useful step in evaluation. For clindamycin, delayed maculopapular exanthems are the most common reactions. There are case reports of clindamycin associated with drug rash with eosinophilia and systemic symptoms (DRESS), acute generalized exanthematous pustulosis (AGEP), acute febrile neutrophilic dermatosis, and symmetrical drug-related intertriginous and flexural exanthema (SDRIFE). For linezolid, cases of hypersensitivity were exceedingly rare and included urticaria, angioedema, anaphylaxis, delayed rashes, and DRESS. For metronidazole, only rare cases were found across a broad spectrum of reactions including allergic contact dermatitis, fixed drug eruption, angioedema, anaphylaxis, serum sickness-like reaction, SJS/TEN, AGEP, SDRIFE, and a possible case of DRESS. IgE-mediated reactions and anaphylaxis to these types of antibiotics are uncommon, and reports of skin testing concentrations and desensitization protocols are largely limited to case reports and series. Non-irritating skin testing concentrations have been reported for gentamycin, tobramycin, and clindamycin. Published desensitization protocols for intravenous and inhaled tobramycin, oral clindamycin, intravenous linezolid, and oral and intravenous metronidazole have also been reported and are reviewed.

Pediatric Drug Allergies: Updates on Beta-Lactam, Nonsteroidal Anti-Inflammatory Drug, and Chemotherapeutic Reactions

Adverse drug reactions are frequently reported in pediatric patients. In this review article, the authors discuss pediatric drug allergies with emphasis on the most common culprits, beta-lactam antibiotics and non-steroidal anti-inflammatory drugs. The authors also discuss reactions to non-beta-lactam antibiotics and chemotherapeutics. Skin testing has not yet been validated for many drugs, although notable exceptions include penicillin and carboplatin. The gold standard for diagnosis in most cases remains drug challenge, and the need for penicillin skin testing prior to oral provocation challenge has been questioned in recent studies. Successful desensitizations have also been reported with several drugs.

Model Based Evaluation of Hypersensitivity Adverse Drug Reactions to Antimicrobial Agents in Children

Drug use in children is-in most cases-supported by extrapolation of data generated from clinical trials in adult populations. This puts children at higher risk of developing adverse drug reactions (ADRs) due to "off-label" use of drugs and dosing issues. Major types of ADRs are drug hypersensitivity reactions, an idiosyncratic type of ADRs that are largely unpredictable and can cause high morbidity and mortality in a hard-to-identify specific population of patients. Lack of a complete understanding of the pathophysiology of DHRs and their unpredictive nature make them problematic in clinical practice and in drug development. In addition, ethical and legal obstacles hinder conducting large clinical trials in children, which in turn make children a "therapeutic orphan" where clear clinical guidelines are lacking, and practice is based largely on the personal experience of the clinician, hence making modeling desirable. This brief review summarizes the current knowledge of model-based evaluation of diagnosis and management of drug hypersensitivity reactions (DHRs) to antimicrobial drugs in the pediatric population. Ethical and legal aspects of drug research in children and the effect of different stages of child development and other factors on the risk of DHRs are discussed. The role of animal models, in vitro models and oral provocation test in management of DHRs are examined in the context of the current understanding of the pathophysiology of DHRs. Finally, recent changes in drug development legislations have been put forward to encourage drug developers to conduct trials in children clearly indicate the urgent need for evidence to support drug safety in children and for modeling to guide these clinical trials.

Guideline-Discordant Preoperative Gentamicin Dosing and the Risk of Gentamicin Associated Nephrotoxicity in Urologic Surgery

OBJECTIVE

To determine the rate of and predictors for guideline-discordant preoperative gentamicin dosing in urologic surgery and to assess the risk of nephrotoxicity in patients who receive the recommended high-dose prophylaxis.

MATERIALS AND METHODS

We retrospectively reviewed all adult patients who received preoperative gentamicin for urologic surgery from January 1, 2017 - October 3, 2019. Doses were categorized as guideline-concordant or -discordant using a cutoff of 4.5 mg/kg dosing weight. We used multivariable logistic regression to identify predictors for guideline-discordant dosing. Postoperative kidney injury was assessed using RIFLE criteria.

RESULTS

Among 2134 patients, 89% received a preoperative dose ≤ 4.5 mg/kg. Older age (70+ years) and endoscopic surgery were significant risk factors for guideline-discordant dosing (OR 2.54, P< 0.001; OR 6.21, P<0.001). Among 735 patients with complete data, there was no significant difference in the risk of kidney injury between those who received a dose less than 4.5 mg/kg and those who received a higher dose (OR 0.89, 95% CI: 0.26 - 2.99, P = 0.75).

CONCLUSION

Preoperative gentamicin is commonly administered at lower than recommended doses for urologic surgery. Older age and endoscopic surgery are significant predictors of guideline-discordant dosing. The risk of kidney injury following high-dose preoperative gentamicin for urologic procedures is likely comparable to the risk at lower doses.

[Adverse reactions of drugs specifically used for treatment of SARS-CoV-2 infection]

Currently, there is no treatment approved for COVID-19. Numerous drugs are being used in an empirical manner according to experience and availability. Studies demonstrating their efficacy and safety are still to be published. Thus, it is of vital importance for healthcare workers to be well informed and updated regarding possible immunological and non-immunological adverse effects regarding such treatments. In this narrative revision, the rationale use of these treatments in the SARS-CoV-2 infection is emphasized as well as their most frequently described adverse drug reactions. Drugs that are being essayed to counteract both clinical phases that are thought to take place in the severe stage of this disease are included; an initial phase where a viral infection prevails and a second phase where an inflammatory response takes over. Adverse reactions registered in the Pharmacovigilance Program of our hospital before the onset of this pandemic have also been included.

Adverse reactions of drugs specifically used for treatment of SARS-CoV-2 infection

Currently, there is no treatment approved for COVID-19. Numerous drugs are being used in an empirical manner according to experience and availability. Studies demonstrating their efficacy and safety are still to be published. Thus, it is of vital importance for healthcare workers to be well informed and updated regarding possible immunological and non-immunological adverse effects regarding such treatments. In this narrative revision, the rationale use of these treatments in the SARS-CoV-2 infection is emphasized as well as their most frequently described adverse drug reactions.

Drugs that are being essayed to counteract both clinical phases that are thought to take place in the severe stage of this disease are included; an initial phase where a viral infection prevails and a second phase where an inflammatory response takes over. Adverse reactions registered in the Pharmacovigilance Program of our hospital before the onset of this pandemic have also been included.

A Rare Case of Acute Generalized Exanthematous Pustulosis with Drug-Induced Liver Injury caused by Pyrazinamide

Acute Generalized Exanthemataous Pustulosis (AGEP) is a rare acute pustular eruption that is mostly induced by drugs. Aside from cutaneous eruptions, systemic symptoms such as leukocytosis, neutrophilia, and internal organ involvement such as liver, kidney, respiratory system, and bone marrow, may occur, although uncommon. Liver involvement usually results in a two- or three-fold increase of liver enzymes and rarely exceeds that. Pyrazinamide is the first-line anti-tuberculosis drug that is potentially hepatotoxic, but rarely shows dermatologic manifestations. We report a rare case of AGEP with drug induced liver injury due to pyrazinamide in a young patient with tuberculosis.

Diagnostic procedures & practices in drug allergy/hypersensitivity: a survey of 13 Asian countries

BACKGROUND

The issues and challenges in the diagnosis of drug allergy/hypersensitivity among children and adults in Asia are likely to be different from non-Asian countries.

OBJECTIVE

To study the diagnostic modalities used in the evaluation and management of drug allergy/drug hypersensitivity reactions (DHRs) among member societies of the Asia Pacific Association of Allergy, Asthma and Clinical Immunology (APAAACI).

METHODS

A questionnaire comprising 41 questions was circulated electronically to member societies and individual members of APAAACI between January 23, 2020 and March 6, 2020.

RESULTS

Twenty-six respondents from 15 member societies and 1 individual member responded. European DHR guidelines were most commonly used. Skin prick and intradermal testing was used by 100%, with only 60% having access to commercial penicillin skin test reagents. In vitro-specific IgE tests were used by 75%, and basophil activation test by 56.3% for immediate DHR. Patch tests were used by 75% in contrast to lymphocyte transformation tests by 25% for nonimmediate DHR. Drug provocation tests were used by 68.8%, the most common indication being to exclude hypersensitivity where history/symptoms were not suggestive of drug hypersensitivity/allergy (93.3%). Human leukocyte antigen (HLA) genotype testing was mandatory among 25% respondents before new carbamazepine prescriptions, and 8.3% for allopurinol prescriptions.

CONCLUSIONS

There was increased use of skin testing for iodinated contrast media hypersensitivity and patch testing for nonimmediate DHR. HLA genotype testing prior to new carbamazepine, allopurinol and abacavir prescriptions remain variable despite strong associations for severe cutaneous adverse reactions with Asian ethnicity. Results of this survey form a useful framework for developing educational and training needs and for improving access to drug allergy diagnostic and treatment modalities across APAAACI member societies.

Genetic Association of Co-Trimoxazole-Induced Severe Cutaneous Adverse Reactions Is Phenotype-Specific: HLA Class I Genotypes and Haplotypes

Co-trimoxazole (CTX) causes various forms of severe cutaneous adverse reactions (SCARs). This case-control study was conducted to investigate the involvement between genetic variants of human leukocyte antigen (HLA) and CYP2C9 in CTX-induced SCARs, including Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) and drug reaction with eosinophilia and systemic symptoms (DRESS) in Thai patients. Thirty cases of CTX-induced SCARs were enrolled and compared with 91 CTX-tolerant controls and 150 people from the general Thai population. Cases comprised 18 SJS/TEN and 12 DRESS patients. This study demonstrated that genetic association of CTX-induced SCARs was phenotype-specific. HLA-B*15:02 and HLA-C*08:01 alleles were significantly associated with CTX-induced SJS/TEN, whereas the HLA-B*13:01 allele was significantly associated with CTX-induced DRESS. In addition, a significant higher frequency of HLA-A*11:01-B*15:02 and HLA-B*13:01-C*03:04 haplotypes were detected in the group of CTX-induced Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) and DRESS cases, respectively. Genetic association of CTX-induced SCARs is phenotype-specific. Interestingly, these association was observed only in HIV-infected patients but not in non-HIV-infected patients.

N-acetyltransferase 2 enzyme genotype-phenotype discordances in both HIV-negative and HIV-positive Nigerians

BACKGROUND

The N-acetyltransferase 2 (NAT2) enzyme has been understudied in Nigerians including genotype-phenotype association studies.

OBJECTIVE

The aim of this study was NAT2 haplotype identification and genotype-phenotype investigations in HIV-positive and HIV-negative Nigerians.

PATIENTS AND METHODS

Phenotypes included self-reported sulphonamide hypersensitivity survey, experimental and computational NAT2 phenotyping. The NAT2 gene was amplified by PCR. Gene sequencing used ABI 3730 and Haploview 4.2 for haplotype reconstruction. Genotype-phenotype analyses used the χ P-value and odds ratio with a 95% confidence interval.

RESULTS

Self-reported sulphonamide hypersensitivity showed a prevalence of 3.1 and 12.4% in HIV-positive and HIV-negative Nigerians, respectively. NAT2 genetic variants 191G>A, 282C>T, 341T>C, 481C>T, 590G>A, 803A>G and 857G>A were not significantly different between both groups (odds ratio=0.87; 95% confidence interval: 0.54-1.38, P=0.55). Nine haplotypes: NAT2*4, NAT2*12A, NAT2*13A, NAT2*5B, NAT2*6A, NAT2*7B, NAT2*5C, NAT2*14B and NAT2*14A had frequencies more than 1%, whereas NAT2*12B had 1.1% in the HIV-positive and 0.4% in the HIV-negative group. Overall, slow acetylator haplotypes made up 68%. The NAT2*12 signature single-nucleotide polymorphism was in high linkage disequilibrium with signature single-nucleotide polymorphism for NAT2*13 (D'=0.97, r=0.61) and NAT2*5 (D'=0.98, r=0.64). Genotype-phenotype association analysis showed haplotypes NAT2*13A, NAT2*5C, NAT2*7B and NAT2*14A to be associated strongly with the slow metabolic phenotype (P=0.002, 0.029, 0.032 and 0.050, respectively). Computational phenotypes were similar, with 30.9, 66 and 3.1% for slow, intermediate and rapid acetylators, respectively, among HIV-positive Nigerians and 31.2, 66.3 and 2.5% among the HIV-negative group. Overall, slow phenotypes made up 31%.

CONCLUSION

NAT2 haplotype frequencies are similar in Nigerians, irrespective of HIV status, but genotype-phenotype discordances exist.

Non-β-Lactam Antibiotic Hypersensitivity Reactions

OBJECTIVES

Antibiotics are among the most common prescriptions in children, and non-β-lactam antibiotics (NBLAs) account for almost half of those prescribed in Australian pediatric hospitals. Despite this, data on NBLA hypersensitivity in children are limited. This study describes reported hypersensitivity reactions to NBLAs in children and the results of allergy evaluation.

METHODS

Children with a suspected NBLA allergy who had skin testing and/or an intravenous or oral challenge test (OCT) between May 2011 and June 2018 were included. Patients were excluded if they were >18 years old or did not complete the allergy evaluation for any reason other than allergic reaction.

RESULTS

Over the 7-year study period, 141 children had 150 allergy evaluations of 15 different NBLAs. The median time from the initial reported reaction to allergy evaluation was 1.9 (range 0.1-14.9) years. Overall, 27 of the 150 (18.0%) challenge tests to NBLAs had positive results, with the rate of positive OCT results being highest for trimethoprim-sulfamethoxazole (15 of 46; 32.6%) and macrolides (8 of 77; 10.4%). Although 4 children reported initial anaphylactic reactions, no patients had severe symptoms on rechallenge or required adrenaline. Of the challenges that had positive results, the majority of children (23 of 27; 85.2%) had symptoms on repeat challenge similar to those that were initially reported.

CONCLUSIONS

Overall, 8 of 10 children with NBLA allergy could be delabeled. On average, patients waited 1.9 years to be rechallenged. Timely access to allergy evaluation to delabel these patients is needed to preserve first-line antibiotics.

Pediatric Drug Allergies: Updates on Beta-Lactam, Nonsteroidal Anti-Inflammatory Drug, and Chemotherapeutic Reactions

Adverse drug reactions are frequently reported in pediatric patients. In this review article, the authors discuss pediatric drug allergies with emphasis on the most common culprits, beta-lactam antibiotics and non-steroidal anti-inflammatory drugs. The authors also discuss reactions to non-beta-lactam antibiotics and chemotherapeutics. Skin testing has not yet been validated for many drugs, although notable exceptions include penicillin and carboplatin. The gold standard for diagnosis in most cases remains drug challenge, and the need for penicillin skin testing prior to oral provocation challenge has been questioned in recent studies. Successful desensitizations have also been reported with several drugs.

Macrolide Allergic Reactions

Macrolides are antimicrobial agents that can be used to treat a variety of infections. Allergic reactions to macrolides occur infrequently but can include minor to severe cutaneous reactions as well as systemic life-threatening reactions such as anaphylaxis. Most reports of allergic reactions occurred in patients without prior exposure to a macrolide. Cross-reactivity among macrolides may occur due to the similarities in their chemical structures; however, some published literature indicates that some patients can tolerate a different macrolide. Most published reports detailed an allergic reaction to erythromycin. Desensitization protocols to clarithromycin and azithromycin have been described in the literature. The purpose of this article is to summarize macrolide-associated allergic reactions reported in published literature. An extensive literature search was conducted to identify publications linking macrolides to hypersensitivity reactions.

Aminoglycoside Allergic Reactions

Aminoglycosides are antimicrobial agents that are primarily used for infections caused by Gram-negative pathogens. The purpose of this article is to review the allergic reactions reported in the published literature to aminoglycoside antibiotics. A thorough PubMed search was conducted and excluded non-allergic adverse reactions to aminoglycosides. Allergic reactions to aminoglycosides occur infrequently, but can include cutaneous reactions as well as systemic reactions, including anaphylaxis. Of the evaluated aminoglycosides, gentamicin had the most reported allergic reactions, including the most reports of anaphylaxis, followed by tobramycin, and then amikacin. Most reports of allergic reactions occurred in patients who had a prior exposure to some dosage form of an aminoglycoside. Cross-reactivity among aminoglycosides is common and occurs due to the similarities in their chemical structures. Desensitization protocols to tobramycin have been described in the literature.

Antimicrobial Desensitization: A Review of Published Protocols

Antimicrobial desensitization represents a last-line option for patients with no alternative therapies, where the benefits of this intensive process must outweigh the potential harm from drug exposure. The goal of antimicrobial desensitization procedures is to establish a temporary state of tolerance to drugs that may otherwise cause hypersensitivity reactions. While no universal antimicrobial desensitization protocols exist, this review critically analyzes previously published desensitization protocols. The purpose of this review is to provide a greater insight for clinicians and institutions to ensure desensitization procedures are efficacious while minimizing potential for patient harm. With an increasing rate of antimicrobial resistance and the critical need to preserve antimicrobial agents, desensitization may represent another option in our antimicrobial stewardship toolkit.

Drug hypersensitivity in HIV infection

PURPOSE OF REVIEW

Immune-mediated adverse drug reactions (IM-ADRs) are many times more common in HIV-infected patients. Usual offending drugs include antiretroviral and antiinfectives, but the burden of specific drug IM-ADRs is population-specific; changing as new and fixed dose combinations enter the market, and drug-resistance patterns demand. This review considers recent literature on epidemiology, mechanisms, clinical management and prevention of IM-ADRs amongst persons living with HIV/AIDS.

RECENT FINDINGS

Epidemiological studies continue to describe high rates of delayed hypersensitivity to known offenders, as well as similar reactions in preexposure prophylaxis. IM-ADRs to oral and injectable integrase strand transfer inhibitors are reported with expanding use. The clinical spectrum and management of IM-ADRs occurring in HIV-infected populations is similar to uninfected; with exceptions such as a recently described severe delayed efavirenz DILI with high mortality. Furthermore, the context can be unique, such as the lower than expected mortality in a Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) cohort from a HIV/TB high burden setting. Programmatic data showing the near complete elimination of Abacavir drug hypersensitivity syndrome following implementation of HLA-B57:01 screening is a stellar example of how prevention is possible with mechanistic insight.

SUMMARY

IM-ADRs remain a challenge in persons living with HIV. The complexities posed by polypharmacy, overlapping drug toxicities, drug interactions, overlap of IM-ADRs with other diseases, limited alternative drugs, and vulnerable patients with advanced immunosuppression with high mortality, necessitate increased use of drug provocation testing, treat-through and desensitization strategies. There is an urgent need for improved diagnostics and predictive biomarkers for prevention, or to guide treat-through, rechallenge and desensitization approaches.

Glutathione S-transferase polymorphisms in patients with photosensitive and non-photosensitive drug eruptions

BACKGROUND

Glutathione S-transferases (GSTs) play a critical role in cellular protection against oxidative damage. Polymorphisms in three major GST loci have been described. A number of studies have looked for an association between GSTs and skin diseases.

PURPOSE

To ascertain the possibility that polymorphisms in the GSTM1, GSTT1, and GSTP1 genes may predict the development of photo-induced and non-photo-induced drug eruptions.

METHODS

A cohort of 40 patients with drug eruptions, 10 of whom had developed a photo-induced drug reaction, and matched controls (116 for GSTM1 and GSTT1, 120 for GSTP1) were studied. Genotyping was conducted using direct sequencing and polymerase chain reaction.

RESULTS

The GSTP1 Val/Val genotype was significantly associated with non-photosensitive drug eruptions (OR = 3.64, P value = 0.038), whereas associations observed between GSTP1, GSTM1, GSTT1 polymorphisms and photosensitive drug eruptions did not reach statistical significance.

CONCLUSIONS

Variations in GSTP1 may affect the risk to develop non-photo-induced drug eruptions. These results warrant confirmatory studies in a larger patient sample.

Pediatric Drug Hypersensitivity

PURPOSE OF REVIEW

Pediatric drug hypersensitivity is a rapidly evolving field. The purpose of this paper is to review the current state of pediatric drug hypersensitivity and highlight new developments in diagnosis and management.

RECENT FINDINGS

This paper will discuss the safety and use of risk stratification to proceed directly to oral challenge without prior skin testing for β-lactam reactions. We review unique aspects of pediatric drug challenges and desensitizations. It is important to accurately diagnose pediatric drug hypersensitivity reactions through a detailed history, physical examination, and available diagnostic testing. Understanding of the underlying mechanism leads to appropriate classification which is necessary to direct management. The decision to perform drug challenge, desensitization, or recommend avoidance of a medication can have a significant impact on a patient's treatment. Utilization of weight-based dose and infusion rate adjustments for current drug challenge and desensitization protocols optimize success.

A practical management of children with antibiotic allergy

About 10% of the parents reported that their children are allergic to one drug and the betalactam antibiotics are the most frequently suspected. Even if most of the adverse events following antibiotic prescriptions to children are considered allergic, after a full allergy work-up only a few of the suspected reactions are confirmed. For this reason, many children are incorrectly labelled as "allergic" and this represents an important challenge for the choice of the antibiotic therapy in these "labelled" children, who are frequently improperly deprived of narrow-spectrum antibiotics because considered as allergic. When an allergic reaction is suspected a precise diagnosis and a choice of a safe and effective alternative is essential for the future antibiotic option. In the light of this, the main aim of this paper is to try to provide a practical approach to managing the individuals who have reported adverse reactions to antibiotics.

SIAIP position paper: provocation challenge to antibiotics and non-steroidal anti-inflammatory drugs in children

Drug hypersensitivity reactions (DHRs) in childhood are mainly caused by betalactam or non-betalactam antibiotics, and non-steroidal anti-inflammatory drugs (NSAIDs). Laboratory tests for identifying children who are allergic to drugs have low diagnostic accuracy and predictive value. The gold standard to diagnose DHR is represented by the drug provocation test (DPT), that aims of ascertaining the causative role of an allergen and evaluating the tolerance to the suspected drug. Different protocols through the administration of divided increasing doses have been postulated according to the type of drug and the onset of the reaction (immediate or non immediate reactions). DPT protocols differ in doses and time interval between doses. In this position paper, the Italian Pediatric Society for Allergy and Immunology provides a practical guide for provocation test to antibiotics and NSAIDs in children and adolescents.

Rifampicin-Induced Fever in a Patient with Brucellosis: A Case Report

We present a 35-year-old female patient who was started on rifampicin (900 mg orally once daily) and trimethoprim/sulfamethoxazole (TMP/SMX) (160/800 mg orally twice daily) after being diagnosed with brucellosis. Following defervescence and improvement in her general condition, fever recurred on the 12th day of treatment. A re-challenge drug test lead to causality assessment and treatment was switched to a combination of streptomycin (1 g intramuscularly) for 10 days and TMP/SMX (160/800 mg orally twice daily) for 4 weeks. Our patient is doing well after 12 months of follow-up.

Rash induced by enteral vancomycin therapy in an older patient in a long-term care ventilator unit: case report and review of the literature

BACKGROUND

Oral vancomycin is a first-line treatment for severe Clostridium difficile colitis. Oral vancomycin is perceived to lack systemic absorption or systemic adverse effects; however, a few cases of hypersensitivity to oral vancomycin have been reported, all in hospitalized patients.

CASE PRESENTATION

In the present case, a 66-year-old woman with end-stage neurodegenerative disease residing in a long-term care facility developed a maculopapular rash following treatment with enteral vancomycin for recurrent C. difficile colitis. The rash resolved after withdrawal of the drug.

CONCLUSION

Rashes associated with oral vancomycin treatment include maculopapular rash, urticaria, red man syndrome, and linear IgA bullous dermatitis. Risk factors for systemic vancomycin absorption include renal insufficiency, severe intestinal inflammation, and high vancomycin dose and duration. Routine serum testing of vancomycin levels, even in these high risk cases, is not recommended. Clinicians should be aware that enteral vancomycin can cause hypersensitivity reactions which may be serious.

Dapsone-associated fixed drug eruption

INTRODUCTION

Dapsone is a sulfone drug used to treat infectious conditions and also numerous dermatologic diseases. Fixed drug eruption is a distinctive adverse cutaneous reaction associated with the initial administration and subsequent delivery of a specific agent. Areas covered: The authors preformed a literature search using the following keywords: dapsone, fixed drug eruption, and adverse cutaneous drug reaction. Bibliographies were also reviewed for pertinent articles. The results were combed for relevant papers and reviewed. Articles pertaining to dapsone-associated fixed drug eruption were included. Expert commentary: The majority of cases of dapsone-associated fixed drug eruption in the literature come from Africa or India where there is a high prevalence of patients treated for leprosy. Characteristics of these cases are similar to fixed drug eruption described in the western literature, with differences in frequency of multiple versus solitary lesions. Dapsone-associated fixed drug eruption should be considered when reviewing the drug history of a patient with fixed drug eruption. In the case of darker pigmented individuals, multiple fixed drug eruption lesions may be more common. Multiple lesions may mimic Kaposi's sarcoma in human immunodeficiency virus positive patients. Dapsone-associated fixed drug eruption should be considered in the differential diagnosis of multiple hyperpigmented lesions.

Proven Non-β-Lactam Antibiotic Allergy in Children

BACKGROUND

Parallel to the increasing use of non-β-lactam (NBL) antibiotics, allergic reactions to this drug group seem to increase. Data about NBL antibiotic hypersensitivity in children are limited. The aim of this study is to evaluate characteristic reactions to NBL antibiotics in children.

METHOD

Patients with suspected NBL allergy were assessed between 2011 and 2015. Characteristics of the reactions and results of skin and drug provocation tests (DPTs) were recorded.

RESULTS

In total, 96 patients aged 75.15 ± 56.77 months (range: 3-208) were assessed. Clarithromycin (63.6%) was the most common cause of reactions reported. After ingestion of NBL antibiotics, maculopapular rash, urticaria/angioedema and anaphylaxis presented in 48.9, 40.7 and 10.4% of the patients, respectively. Tests were performed in 85 patients. Intradermal tests were positive in 3 patients (clarithromycin, ciprofloxacin and cotrimoxazole) and DPT was positive in 1 patient (clarithromycin). Eleven patients could not be tested. Seven patients had severe anaphylaxis, and 4 patients with urticaria/angioedema had to take their medications at the time of the reaction so desensitization was performed. When only patients confirmed by tests were evaluated, NBL allergy was 4.7% (4/85) in our study group. However, when patients who could not be tested, but were regarded as suffering from drug hypersensitivity according to clinical findings, were included, the frequency of NBL allergy was 15.6% (15/96).

CONCLUSION

Most of the children with suspected NBL do not have true hypersensitivity. The frequency of confirmed hypersensitivity is low, and thus a detailed history should be taken from patients with suspected NBL hypersensitivity and DPTs should be performed in patients without contraindications.

A Case Report of Rash at Peritoneal Dialysis Exit Site

The International Society for Peritoneal Dialysis recommends the regular application of topical antibiotic-containing preparations in addition to a routine exit site care to reduce the risk of exit site infection (ESI). Among these prophylactic antimicrobial preparations, topical gentamicin is one of the widely used and effective antibiotics for prevention of ESI and peritonitis in peritoneal dialysis (PD) patients. Overall, topical gentamicin is well tolerated; however, its use can be associated with the development of allergic contact dermatitis (ACD). We describe a first reported case of PD catheter exit site contact ACD due to topical gentamicin mimicking ESI. The patient in this report developed worsening violaceous in color and pruritic rash surrounding the PD catheter exit site that appeared 3 weeks after the initiation of gentamicin cream. The association between development of rash and initiation of topical gentamicin led to a suspicion of local reaction to gentamicin rather than ESI. Skin biopsy confirmed ACD. Discontinuation of the provoking agent and subsequent treatment with topical hydrocortisone application led to a resolution of the exit site rash. Any rash at a PD catheter exit site should be considered infectious until proven otherwise. However, it is important to be aware of noninfectious etiologies of exit site rashes as the treatment of these 2 conditions differs.

Immunologic evaluation of patients with cefotetan-induced anaphylaxis

Cefotetan is a commonly prescribed second-generation cephalosporin that acts against a wide range of bacteria. However, cefotetan-induced hypersensitivity has rarely been reported. We report 2 cases of cefotetan-induced anaphylaxis with immunologic evaluation. The first case was a 70-year-old asthmatic woman who had dyspnea and hypotension during administration of cefotetan, in which high serum-specific IgE to cefotetan-human serum albumin (HSA) conjugate was detected by enzyme-linked immunosorbent assay. The second case was a 63-year-old asthmatic woman who complained of chest tightness and dyspnea during cefotetan infusion, in which high serum-specific IgG1 and IgG4 with no serum specific IgE to cefotetan-HSA conjugate was detected. The basophil activation test using basophils from the patient showed a significant up-regulation of CD63 with the addition of anti-IgG4 antibody compared with that in non-atopic healthy controls. In conclusion, cefotetan can induce anaphylaxis, which may involve both IgE- and IgG4-mediated responses in the pathogenic mechanism.

International consensus on (ICON) anaphylaxis

ICON: Anaphylaxis provides a unique perspective on the principal evidence-based anaphylaxis guidelines developed and published independently from 2010 through 2014 by four allergy/immunology organizations. These guidelines concur with regard to the clinical features that indicate a likely diagnosis of anaphylaxis -- a life-threatening generalized or systemic allergic or hypersensitivity reaction. They also concur about prompt initial treatment with intramuscular injection of epinephrine (adrenaline) in the mid-outer thigh, positioning the patient supine (semi-reclining if dyspneic or vomiting), calling for help, and when indicated, providing supplemental oxygen, intravenous fluid resuscitation and cardiopulmonary resuscitation, along with concomitant monitoring of vital signs and oxygenation. Additionally, they concur that H1-antihistamines, H2-antihistamines, and glucocorticoids are not initial medications of choice. For self-management of patients at risk of anaphylaxis in community settings, they recommend carrying epinephrine auto-injectors and personalized emergency action plans, as well as follow-up with a physician (ideally an allergy/immunology specialist) to help prevent anaphylaxis recurrences. ICON: Anaphylaxis describes unmet needs in anaphylaxis, noting that although epinephrine in 1 mg/mL ampules is available worldwide, other essentials, including supplemental oxygen, intravenous fluid resuscitation, and epinephrine auto-injectors are not universally available. ICON: Anaphylaxis proposes a comprehensive international research agenda that calls for additional prospective studies of anaphylaxis epidemiology, patient risk factors and co-factors, triggers, clinical criteria for diagnosis, randomized controlled trials of therapeutic interventions, and measures to prevent anaphylaxis recurrences. It also calls for facilitation of global collaborations in anaphylaxis research. IN ADDITION TO CONFIRMING THE ALIGNMENT OF MAJOR ANAPHYLAXIS GUIDELINES, ICON: Anaphylaxis adds value by including summary tables and citing 130 key references. It is published as an information resource about anaphylaxis for worldwide use by healthcare professionals, academics, policy-makers, patients, caregivers, and the public.