Drug provocation tests in children: All that glitters is not gold

A proper allergy work-up, based on the gold standard drug provocation test (DPT), usually rules out suspected drug hypersensitivity in children. These tests are generally open, given their high efficiency compared with double-blind placebo-controlled DPTs. Although their negative predictive value is excellent, no studies have calculated their positive predictive value, highly dependent on the prevalence of the disease. Most studies have found a rate of <5%-10% of true beta-lactam hypersensitivity in children. Given this low prevalence (pre-test probability), a few false-positive results can significantly reduce the estimated positive predictive value. False positives may arise from the nocebo effect during the test, including nocebo by proxy, or from observer bias, which depends on professional expertise and organizational circumstances. Some studies have found a high rate of tolerance on a second DPT in children who failed the first, but these results may be affected by the interval between the two tests, of a year or more in most cases, reflecting a loss of hypersensitivity over time. Taking into account the low rate of positive DPTs, with commonly mild reactions, we suggest confirming nonsevere positive DPTs with a second provocation performed soon after the first, especially in the case of beta-lactam antibiotics, in order to improve the diagnostic accuracy, de-label more patients, and achieve a better estimation of true drug hypersensitivity prevalence. In case of mild immediate reactions, the potential benefits of a second DPT should be carefully weighed against the risk of anaphylaxis.

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.

Management of coronavirus disease 2019 vaccine-induced cutaneous complications: A comprehensive literature review

Despite the numerous reports of cutaneous manifestations associated with vaccines for coronavirus disease 2019 (COVID-19), the relationship between COVID-19 vaccines and cutaneous side effects remains unevaluated. In this review, we examine these manifestations and their management. Reported dermatoses included injection-site reaction (early and delayed), type I allergic reaction, morbilliform eruption, pityriasis rosea, Sweet syndrome, lichen planus, psoriasis, herpes zoster reactivation, erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis (TEN). The most common COVID-19 vaccination-related cutaneous manifestations are delayed local reactions, approximately 66% of which are associated with the Moderna vaccine, and 33% with the Pfizer vaccine. Aside from mild injection-site reactions, severe reactions include anaphylaxis and TEN. Most reactions, except for Stevens-Johnson syndrome and anaphylaxis, though unpredictable and unpreventable are mild and can be treated symptomatically. Findings from this review should allow primary care physicians and dermatologists to reach faster diagnosis and initiate prompt intervention.

Hypersensitivity to Non-Steroidal Anti-Inflammatory Drugs on a pediatric Portuguese cohort

Summary

Background. Non-steroidal anti-inflammatory drugs (NSAID)/analgesics (paracetamol) are among the most common causes of drug hypersensitivity reactions in children, with a reported prevalence of around 0.3% in the pediatric population. Paracetamol and ibuprofen are the most commonly reported culprits in the pediatric population. Our objective was to describe the allergy workup to NSAID/paracetamol of a pediatric population monitored in an allergy outpatient clinic. Methods. Retrospective observational study by consulting the medical records of patients evaluated in a pediatric outpatient clinic with history of NSAID/paracetamol, between January 2016 to August 2022. Results. A total of 43 patients have been evaluated for NSAID/paracetamol suspected allergy: 53.5% females, mean age of 9.8 ± 5.1 years, 47.7% atopic. The drugs reported as culprits were: ibuprofen (75.6%), paracetamol (17.8%), metamizole (4.4%) and naproxen (2.2%) and clinical manifestations were mainly urticaria/angioedema and maculopapular exanthema. Skin tests were performed in 7 patients: paracetamol (n = 5) and metamizole (n = 2), which were all negative. Fourty-six drug provocation tests were performed: 28 with the culprit drug and 18 with an alternative one; only 2 were positive (ibuprofen - culprit NSAID group): one immediate periorbital angioedema and one delayed lip edema with oropharyngeal tightness. Conclusions. The investigation of allergy to NSAID/paracetamol in children remains a challenge. In our population, ibuprofen was the most common NSAID reported. There were only 2 (4.3%) mild reactions on DPT. We could allow the use of the culprit NSAID/analgesic in 11 patients and an alternative one in 9 patients. This study highlights the importance of DPT in children for a correct diagnosis of NSAID hypersensitivity and selection of an alternative drug.

In vitro diagnostic testing for drug allergy in children

Diagnosing Drug Hypersensitivity Reactions (DHRs) could be a complicated process especially in children, since allergic-like manifestation at this age is more often the expression of concomitant infections rather than a actual DHRs. In vivo tests are usually suggested as a first step; however, prick and intradermal tests could be painful and have shown different sensitivity and specificity among published studies. In some cases, in vivo tests such as Drug Provocation test (DPT) could be even contraindicated. Therefore, the need for in vitro testing is compelling, to add useful information along the diagnostic pathway and to limit the need of DPT. In this review, we analyze the different types of in vitro tests, focusing on those used more widely such as specific IgE and on those that are still for research settings, such as basophil activation test and lymphocyte transformation test, but that have shown some useful diagnostic potential.

Primary care doctors' attitude towards drug allergy in Portugal: a questionnaire

Summary

Background. The aim of the study was to learn about perception of drug allergy by general practitioners (GP) from continental Portugal, identify difficulties and educational needs for its management. Methods. A total of 372 answers were obtained. A questionnaire was addressed to GPs. Results. The most commonly identified drugs were antibiotics for 65.3% of the GPs and skin was the most commonly affected organ for 65.8%. Drug allergy was considered as very important in clinical practice by 73.7%, but difficulties in recognizing it were stated by 70.2%. Further education in this field wouldbe welcome by 97.8% of the doctors. The collaboration of Immunoallergology centers was considered non satisfactory by 39.8% of GPs and 45.7% of them stated that two-thirds of the suspected reactions were not investigated. Conclusions. These points deserve consideration in future health educational and organizational strategies.

Pharmacist-led improvement in perioperative antibiotic selection for patients with a penicillin allergy label

DISCLAIMER

In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

Surgical patients with a penicillin allergy label (PAL) are less likely to receive β-lactams for surgical site infection (SSI) prophylaxis and more likely to receive second-line antibiotics, which may increase the risk of SSI, drug toxicities, and associated costs. We assessed the impact of implementing a pharmacist-led quality improvement project to increase the use of cefazolin as a first-line agent in this population.

SUMMARY

After implementation of a pilot project in December 2021, all patients with a PAL and orders for preoperative antibiotics were risk stratified into high- or low-risk categories by a pharmacist. For the low-risk group, cefazolin was recommended. For the high-risk group, cefazolin was avoided and a second-line agent was administered. Our analysis compared 422 preintervention patients (August 15 to November 15, 2021) to 492 postintervention patients (December 15 to March 15, 2022). During the postintervention period, β-lactam usage increased (from 12.6% to 37.8%, P < 0.001), while usage of vancomycin (45.5% vs 29.5%, P < 0.001) and other second-line antibiotics (87.4% vs 62.2%, P < 0.001) declined. There were no adverse reactions reported in the preintervention cohort, with 2 potential adverse reactions reported after the intervention (0% vs 0.4%, P = 0.190). Medication costs based on claims data were 50% to 80% lower for patients receiving cefazolin.

CONCLUSION

In our cohort, a pharmacy-led antibiotic selection algorithm for patients with a PAL receiving perioperative antimicrobial prophylaxis resulted in increased use of β-lactam antibiotics, decreased use of second-line antibiotics, and decreased costs without a significant change in the incidence of adverse reactions.

Delayed Drug Hypersensitivity Reactions: Molecular Recognition, Genetic Susceptibility, and Immune Mediators

Drug hypersensitivity reactions are classified into immediate and delayed types, according to the onset time. In contrast to the immediate type, delayed drug hypersensitivity mainly involves T lymphocyte recognition of the drug antigens and cell activation. The clinical presentations of such hypersensitivity are various and range from mild reactions (e.g., maculopapular exanthema (MPE) and fixed drug eruption (FDE)), to drug-induced liver injury (DILI) and severe cutaneous adverse reactions (SCARs) (e.g., Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP)). The common culprits of delayed drug hypersensitivity include anti-epileptics, antibiotics, anti-gout agents, anti-viral drugs, etc. Delayed drug hypersensitivity is proposed to be initiated by different models of molecular recognition, composed of drug/metabolite antigen and endogenous peptide, HLA presentation, and T cell receptor (TCR) interaction. Increasing the genetic variants of HLA loci and drug metabolic enzymes has been identified to be responsible for delayed drug hypersensitivity. Furthermore, preferential TCR clonotypes, and the activation of cytotoxic proteins/cytokines/chemokines, are also involved in the pathogenesis of delayed drug hypersensitivity. This review provides a summary of the current understanding of the molecular recognition, genetic susceptibility, and immune mediators of delayed drug hypersensitivity.

Viral infections and drug hypersensitivity

Virus infections and T-cell-mediated drug hypersensitivity reactions (DHR) can influence each other. In most instances, systemic virus infections appear first. They may prime the reactivity to drugs in two ways: First, by virus-induced second signals: certain drugs like β-lactam antibiotics are haptens and covalently bind to various soluble and tissue proteins, thereby forming novel antigens. Under homeostatic conditions, these neo-antigens do not induce an immune reaction, probably because co-stimulation is missing. During a virus infection, the hapten-modified peptides are presented in an immune-stimulatory environment with co-stimulation. A drug-specific immune reaction may develop and manifest as exanthema. Second, by increased pharmacological interactions with immune receptors (p-i): drugs tend to bind to proteins and may even bind to immune receptors. Without viral infections, this low affine binding may be insufficient to elicit T-cell activation. During a viral infection, immune receptors are more abundantly expressed and allow more interactions to occur. This increases the overall avidity of p-i reactions and may even be sufficient for T-cell activation and symptoms. There is a situation where the virus-DHR sequence of events is inversed: in drug reaction with eosinophilia and systemic symptoms (DRESS), a severe DHR can precede reactivation and viremia of various herpes viruses. One could explain this phenomenon by the massive p-i mediated immune stimulation during acute DRESS, which coincidentally activates many herpes virus-specific T cells. Through p-i stimulation, they develop a cytotoxic activity by killing herpes peptide-expressing cells and releasing herpes viruses. These concepts could explain the often transient nature of DHR occurring during viral infections and the often asymptomatic herpes-virus viraemia after DRESS.

[ANTIMICROBIAL ALLERGY ASSESSMENT DURING PREGNANCY FOR APPROPRIATE ANTIMICROBIAL USE AT DELIVERY]

BACKGROUND

Avoidance of suspect drugs based solely on a history of drug allergy is detrimental to disease outcomes. Many antimicrobial allergy labels are not usually true allergy. Some studies have demonstrated that antimicrobial allergy assessments can be safely performed on pregnant women. The purpose of this study was to examine the usefulness of antibiotic allergy assessment during pregnancy in Japan.

METHODS

We reviewed pregnant women who reported antimicrobial allergies and were referred to the allergy center. Allergists conducted an interview and skin test and selected antibiotics that could be used at delivery.

RESULTS

Twenty-four pregnant women were referred to as having antimicrobial allergies. Most of the suspected antimicrobials were cephalosporin (13 cases, 52%) and penicillin (9 cases, 36%). Five women were ruled out only by our interviews. Of the remaining 20 cases, 10 were immediate type, 6 were non-immediate type, and 4 were unknown. All 21 pregnant women who needed antimicrobials were able to use the first-line drugs (β-lactam antimicrobials) at the time of delivery. No surgical site infections or allergic reactions were observed.

CONCLUSION

Pregnant women with antimicrobial allergy labels could be evaluated by antimicrobial allergy assessment during pregnancy, and first-line antimicrobials were safely and properly used at delivery.

Diagnostic Value of Oral Provocation Tests in Drug Hypersensitivity Reactions Induced by Nonsteroidal Anti-Inflammatory Drugs and Paracetamol

Oral drug provocation tests (DPT) are the basic diagnostic tool for the detection of hypersensitivity to non-opioid analgesics and for selecting a safe alternative for a patient. They are of great practical importance due to their common use, but the data on the follow-up of patients after negative DPT are still very scarce. We examined the further fate of 164 such adult patients after negative NSAID or paracetamol tests and analyzed which excipients in the studied drugs they could be exposed to after the diagnostic workup. A structured medical interview was performed 32.9 months (mean) after the provocation tests. Of the 164 patients, 131 (79.9%) retook the tested drug and 12 developed another hypersensitivity reaction, giving the estimated negative predictive value of 90.8%. These reactions were induced by acetylsalicylic acid, paracetamol, meloxicam, and diclofenac, and were clinically similar to the initial ones (most commonly urticaria and angioedema). There are 93 generics of these drugs on the local market, containing a total of 33 excipients for which hypersensitivity reactions have been reported. All available generics contain such excipients. Thirty-one patients (20.1%) did not take the previously tested drug again, most often because it was not needed or because they were afraid of another reaction. DPT with analgesics has a high diagnostic performance. A minority of patients had relapsed after reexposure. One of the underestimated reasons for this may be drug excipients provoking a reaction, so it is advisable to use exactly the same medical product that has been negatively tested. Many patients avoid reexposure to a given drug, despite negative tests, therefore very reliable patient education in connection with DPT is highly needed.

Pathology of drug hypersensitivity reactions and mechanisms of immune tolerance

Immune-mediated type IV adverse drug reactions are idiosyncratic in nature, generally not related to the primary or secondary pharmacology of the drug. Due to their complex nature and rarity, these iatrogenic reactions are seldom predicted or encountered during preclinical/early clinical development stages, and often precipitate upon exposure to wider populations (i.e. phase III onwards). They confer a burden on the healthcare sector in both a clinical and financial sense presenting a severe impediment to the drug discovery and development process. Research over the past 50 years has improved our understanding of these reactions markedly as both in vitro and in vivo studies have placed the role of the immune system, in particular; drug-responsive T cells, firmly in the spotlight as the mediators of these reactions. Indeed, the role of different populations of T cells in adverse events and the interaction of drug molecules with HLA proteins expressed on the surface of antigen-presenting cells is of considerable interest. Herein, this review examines the pathways of immune-mediated adverse events including the various T cell subtypes implicated and the mechanisms of T cell activation. Additionally, we address the enigma of immunological tolerance and explore the role tolerance plays in determination of susceptibility to such adverse events even in individuals carrying immunogenic liabilities.

A striking presentation of pustular Sweet syndrome induced by trimethoprim-sulfamethoxazole

We describe a strikingly robust presentation of trimethoprim-sulfamethoxazole (TMP-SMX)-induced pustular Sweet syndrome and discuss how to distinguish it from iododerma and other neutrophil-rich conditions. A review of the literature indicates that TMP-SMX-induced Sweet syndrome (SS) may have higher rates of neutrophilia and greater ocular, mucosal, and musculoskeletal involvement compared to SS from other drugs. Recognizing these features and identifying the offending agent are critical for correctly diagnosing TMP-SMX-induced SS in a timely manner.

Infantile Stevens Johnson syndrome and toxic epidermal necrolysis: A systematic review of clinical features and outcomes in children ages 12 months and under

BACKGROUND/OBJECTIVES

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening mucocutaneous hypersensitivity reactions that carry significant morbidity and mortality. While clinical features are well documented in adult and pediatric patients, infantile cases are rarely reported. Our objective was to synthesize clinical features and outcomes in this population.

METHODS

A literature search was performed from three large databases (PubMed, EMBASE, and Web of Science) to systematically identify reports of SJS/TEN in the infantile period (defined as less than 12 months of age) between 1962 and 2019. Cases determined to represent SJS/TEN based on defined criteria were included. Each case was scored based on Quality Rating Scheme for Studies and Other Evidence. The initial search yielded 4856 publications, of which 19 (n = 26) met final inclusion criteria.

RESULTS

All cases for which body surface area (BSA) involvement was available or able to be approximated (n = 18/26) met criteria for TEN. All cases (n = 26) had mucous membrane involvement, with the oral mucosa most commonly affected (85.7%). Mortality was high within our population with 39.1% of infants expiring, 77.8% secondary to bacterial sepsis. The most common triggers were medications (52.4%), infections (33.3%), and vaccinations (14.3%).

CONCLUSIONS

This review highlights several unique clinical findings amongst infants with SJS/TEN, including increased BSA involvement, higher rates of bacterial sepsis, and higher mortality rates compared to older children and adults. Infants are more likely to present as TEN over SJS. More research is needed to identify triggers, successful treatments, and specific outcomes in this population.

Antibiotic hypersensitivity in cystic fibrosis - Low frequency of anaphylaxis over 16 000 courses

AIMS

Drug hypersensitivity reactions (DHR) to antibiotics are common and a substantial issue in managing patients with cystic fibrosis (CF). This study aimed to assess the prevalence and clinical features as well as risk factors of DHR to antibiotics in CF.

METHOD

A 20-year retrospective study was conducted among 226 CF patients (100 children and 126 adults) attending our centre. The Swedish Registry for Cystic Fibrosis and electronic medical records enabled us to ascertain the number and routes of antibiotic courses. All suspected DHR were evaluated.

RESULTS

The patients had a total of 16 910 antibiotic courses, of which 6832 (40%) were intravenously administered. Of 226 enrolled CF patients, 70 (31%) developed overall 131 DHR to antibiotics. The prevalence of DHR increased with advancing age (P < .001). Beta-lactams elicited 71% of all DHR and piperacillin was the most common single culprit (30% of intravenous and 24% of all DHR). Reactions were mild to moderate and mostly limited to skin; no severe cutaneous adverse reactions were observed. Additionally, anaphylaxis was rare, constituting 2.3% (3/131) of all DHR. Patients with DHR were exposed to significantly more courses of antibiotics than those without DHR (median 124 vs. 46, retrospectively, P < .001).

CONCLUSIONS

DHR to antibiotics, particularly to beta-lactams, are increased in CF patients, and associated with a higher number of cumulative exposures because of recurrent infections. However, severe cutaneous or systemic DHR, such as anaphylaxis, appear to be rare.

Chronic Spontaneous Urticaria in Hong Kong: Clinical Characteristics, Real-World Practice and Implications for COVID-19 Vaccination

PURPOSE

The real-world management and clinical characteristics of chronic spontaneous urticaria (CSU) in Hong Kong and its implications for coronavirus disease 2019 (COVID-19) vaccination are unknown. We investigated the clinical characteristics of patients with CSU and the role of an immunologist-led Urticaria Clinic as well as the impact of CSU on COVID-19 vaccine uptake in Hong Kong.

METHODS

Longitudinal clinical data of 257 CSU patients were collected and analyzed. Association analyses were performed to identify the relationships between variables and factors associated with COVID-19 vaccine uptake.

RESULTS

After the immunologist review, the Weekly Urticaria Activity Score (UAS7) was significantly lower than baseline (median: 0.00 vs. 12.0, P < 0.001). Changes in UAS7 were significantly greater among patients with baseline UAS7 ≥ 16 compared to those with UAS7 < 16 (median: -24.0 vs. -2.00, P < 0.001). CSU patients had lower COVID-19 vaccination rates than the general population with only 176 (68.5%) and 165 (65.0%) receiving at least one dose and 2 doses of vaccination, respectively. The presence of concomitant suspected drug allergy was associated with lower COVID-19 vaccine uptake (odds ratio [OR], 0.47; P = 0.010), while regular pharmacological treatment was associated with higher COVID-19 vaccine uptake among CSU patients (OR, 3.79; P = 0.010).

CONCLUSIONS

A dedicated immunologist-led Urticaria Clinic may effectively improve CSU management and outcomes in Hong Kong.

HLA pharmacogenetic markers of drug hypersensitivity from the perspective of the populations of the Greater Middle East

Specific HLA associations with drug hypersensitivity may vary between geographic regions and ethnic groups. There are little to no data related to HLA-drug hypersensitivity on populations who reside in the Greater Middle East (GME), a vast region spanning from Morocco in the west to Pakistan in the east. In this review, the authors intended to summarize the significant HLA alleles associated with hypersensitive drug reactions induced by different drugs, as have been found in different populations, and to summarize the prevalence of these alleles in the specific and diverse populations of the GME. For example, HLA-B*57:01 allele prevalence, associated with abacavir-induced hypersensitivity, ranges from 1% to 3%, and HLA-DPB1*03:01 prevalence, associated with aspirin-induced asthma, ranges from 10% to 14% in the GME population. Studying pharmacogenomic associations in the ethnic groups of the GME may allow the discovery of new associations, confirm ones found with a low evidence rate and enable cost-effectiveness analysis of allele screening before drug use.

Managing the ADR of Stevens-Johnson syndrome/toxic epidermal necrolysis

INTRODUCTION

Stevens-Johnson syndrome and toxic epidermal necrolysis are severe, life-threatening adverse drug reactions that are collectively known as epidermal necrolysis. The abrupt detachment of the skin and mucositis results in systemic complications such as fluid and electrolyte disturbances, hypothermia, sepsis, organ failure, and death. Management is multidisciplinary and complex.

AREAS COVERED

This present article reviews the principles and best practices in the care of patients with epidermal necrolysis. These include having prompt admissions to optimal care facilities, coordinated specialized care during the acute phase, as well as long-term follow-up to manage chronic sequelae.

EXPERT OPINION

Patients with epidermal necrolysis should be managed in specialized/reference centers that are experienced with the management of the disease. Multi-disciplinary supportive care remains the cornerstone. Current evidence precludes definitive recommendation on any immunomodulatory agent as treatment. Long-term follow-up is required in order to diagnose and treat any chronic sequelae.

Incidence of immediate allergic reactions to mRNA COVID-19 vaccines in adults with drug allergies and other allergic disorders

Concerns have been raised about allergic reactions to messenger ribonucleic acid (mRNA) coronavirus disease 2019 (COVID-19) vaccines. A history of allergic reactions, including anaphylaxis to drugs, has been frequently reported in individuals with anaphylaxis to mRNA vaccines. To estimate the rate of immediate allergic reactions in patients with a history of drug allergy or other allergic disorders. We included adult patients who had received at least 1 dose of an mRNA COVID-19 vaccine at the Special Hospital for Pulmonary Diseases between March 1, 2021, and October 1, 2021, and who reported a history of drug allergy or other allergic diseases (asthma, allergic rhinitis, atopic dermatitis, food or insect venom allergy, mastocytosis, idiopathic anaphylaxis, acute or chronic urticaria, and/or angioedema). Immediate allergic reactions, including anaphylaxis, occurring within 4 hours of vaccination were recorded. Six immediate allergic reactions were noted in the cohort of 1679 patients (0.36%). One patient experienced anaphylaxis (0.06%), which resolved after epinephrine administration, and the other reactions were mild and easily treatable. Most patients with a history of allergies can safely receive an mRNA COVID-19 vaccine, providing adequate observation periods and preparedness to recognize and treat anaphylaxis.

Linear Immunoglobulin a Bullous Dermatosis in Children

Linear Immunoglobulin A Bullous Disease (LABD) is a rare dermatosis whose pathomechanisms are not yet completely understood. LABD has different features characterizing adults and children in terms of potential triggers, clinical manifestations, and prognosis. The aim of the present study is to review all neonatal and pediatric cases of LABD and summarize the major characteristics. Childhood LABD is mainly idiopathic with a benign prognosis. Neonatal cases are difficult to differentiate from infectious diseases and usually have a poor prognosis. Drugs are one of the possible triggers that can activate autoimmune responses through antigen mimicry and epitope spreading as well as different stimuli (e.g., infections, inflammatory diseases, trauma). The gold standard for the diagnosis is based on direct immunofluorescence. Prognosis is generally favorable but often depends on the prompt dermatological diagnosis, treatment and follow-up guaranteed by a multidisciplinary team, including pediatricians for this group of age.

Drugs and Vaccines Hypersensitivity in Children with Mastocytosis

Mastocytosis, a heterogeneous mastcell disease, include three different entities: cutaneous mastocytosis, systemic mastocytosis (SM) and mast-cell sarcoma. Tryptase levels can differentiate cutaneous mastocytosis from SM. In mastocytosis, quick onset drug hypersensitivity reactions (DHRs) that are facilitated by mastcell mediators, are investigated in adults. Due to the limited number of children with mastcell disease and increased serum tryptase levels, the role of drugs in this age group is less studied. In this review, we critically assessed relevant papers related with immediate DHRs in children with mastocytosis and discuss practical issues of the management. In childhood mastocytosis, anaphylaxis is frequently idiopathic, and elevated level of basal tryptase, and high burden of disease may increase the risk. Among drugs, antibiotics, NSAIDs and opioids can potentially induce anaphylaxis, anyway avoidance should be recommended only in case of previous reactions. Moreover, vaccinations are not contraindicated in patients with mastocytosis. The risk of severe systemic reactions after drugs intake seems to be extremely low and in general lower in children than in adults. Anyway, studies on this topic especially focusing on children, are missing to state final recommendations.

Allergy clinic patients' drug hypersensitivity

BACKGROUND

Drug hypersensitivity reaction (DHR) is a common reason for an allergology con- sultation, during which it is not only necessary to gather a thorough medical history, but also to propose and perform diagnostic tests.

OBJECTIVES

The aim of the study was to retrospectively assess the patients with a profile of preliminary drug hypersensitivity diagnosis, the usefulness of NSAID hypersensitivity classifica- tion in outpatient practice, and to analyze the results of skin, provocation, and drug tolerance tests performed in Immunology and Allergy Clinic patients.

METHODS

Around 501 medical records of patients referred to the academic allergy outpatient clinic from 2011 to 2019, and had a preliminary drug hypersensitivity diagnosis were analyzed. The diagnostic and drug tolerance tests results carried out in 269 patients of the Clinic from 2009 to 2019 were then evaluated.

RESULTS

Among the patients referred due to suspected drug hypersensitivity, the majority (n=338, 67.5%) were believed to be hypersensitive to NSAIDs and antibiotics (n=272, 54.3%). In patients with hypersensitivity to NSAIDs, the mixed pattern was the most prevalent (n=73, 21.6%), followed by NECD (n=64, 18.9%) and NIUA (n=55, 16.3%). The second most common drug causing DHR were the antibiotics, mainly β-lactams (n=160, 58.8%), followed by macrolides (n=35, 12.9%). In hypersensitivity caused due to β-lactams, the delayed form was predominant (n=24, 15%) with manifested skin symptoms (n=74, 46.3%). Non-steroidal anti-inflammatory drugs (n=21, 42.9%), followed by antibiotics (n=11, 22.5%) were the commonest causes of ana- phylaxis, as reported by 49 patients.

CONCLUSION

The study shows that a majority of patients with suspected drug hypersensitivity can be classified under the hypersensitivity umbrella based on their medical history, which is the basis for further diagnostic process.