Drug Hypersensitivity

Chlorzoxazone-Induced Fixed Drug Eruption: A Clinical Case Report

Fixed drug eruptions (FDEs) are dermatological manifestations characterized by recurrent lesions at the same site upon re-exposure to the causative drug. We present a novel case of a 32-year-old female who developed bilateral symmetrical erythematous papules on her thighs following the use of chlorzoxazone for chronic back pain. This case is particularly significant as it underscores the potential for this specific drug, which is commonly prescribed, to induce FDE-a reaction previously unreported in the literature. The findings emphasize the necessity for clinicians to maintain a high index of suspicion for drug-induced skin reactions, even with medications considered safe and routinely used. This case serves as a critical reminder of the importance of thorough medication history assessments and the potential implications of drug interactions in dermatological care.

Drugs and the skin: A concise review of cutaneous adverse drug reactions

Drug-induced skin disease or cutaneous adverse drug reactions (CADRs) are terms that encompass the clinical manifestations of the skin, mucosae and adnexa induced by a drug or its metabolites. The skin is the organ most frequently affected by drug reactions, which may affect up to 10% of hospitalized patients and occur in 1-3% of multimedicated patients. Most CADRs are mild or self-resolving conditions; however, 2-6.7% of could develop into potentially life-threatening conditions. CADRs represent a heterogeneous field and can be diagnostically challenging as they may potentially mimic any dermatosis. Currently, there are between 29-35 different cutaneous drug-reaction patterns reported ranging from mild dermatitis to an extensively burnt patient. The most frequently reported are maculopapular rash, urticaria/angioedema, fixed drug eruption and erythema multiforme. Less common but more severe patterns include erythroderma, drug reaction with eosinophilia and systemic symptoms, and Stevens-Johnson syndrome/toxic epidermal necrolysis spectrum. Almost any drug can induce a CADR, but antibiotics, nonsteroidal anti-inflammatory drugs and antiepileptics are the most frequently involved. Different mechanisms are involved in the pathogenesis of CADRs, although in some cases, these remain still unknown. CADRs could be classified in different ways: (i) type A (augmented) or type B (bizarre); (ii) immediate or delayed; (iii) immune-mediated or nonimmune-mediated; (iv) nonsevere or life-threatening; and (v) by their phenotype, including exanthematous, urticarial, pustular and blistering morphology. Recognizing a specific CADR will mostly depend on the ability of the physician to perform a detailed clinical examination, the proper description of the morphology of the skin lesions and supporting laboratory and/or skin biopsy findings.

Clues of HLAs, metabolic SNPs, and epigenetic factors in T cell-mediated drug hypersensitivity reactions

Drug hypersensitivities are common reactions due to immunologic responses. They are of utmost importance because they may generate severe and fatal outcomes. Some drugs may cause Adverse Drug Reactions (ADRs), such as drug hypersensitivity reactions (DHRs), which can occur due to the interaction of intact drugs or their metabolites with Human Leukocyte Antigens (HLAs) and T cell receptors (TCRs). This type develops over a period of 24-72 h after exposure and is classified as type IV of DHRs. Acute generalized exanthematic pustulosis (AGEP), Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) and drug reaction with eosinophilia and systemic symptoms (DRESS) are types of Severe Cutaneous Adverse Reactions (SCARs). In this review, we aim to discuss the types of ADRs, the mechanisms involved in their development, and the role of immunogenetic factors, such as HLAs in type IV DHRs, single-nucleotide polymorphisms (SNPs), and some epigenetic modifications, e.g., DNA/histone methylation in a variety of genes and their promoters which may predispose subjects to DHRs. In conclusion, development of promising novel in vitro or in vivo diagnostic and prognostic markers is essential for identifying susceptible subjects or providing treatment protocols to work up patients with drug allergies as personalized medicine.

Causes and Management of Cutaneous Adverse Drug Reactions: A Comprehensive Review

Cutaneous adverse drug reactions (CADRs) are one of the most broadly studied and rigorously researched conditions in recent dermatological advancements. Also termed as "toxidermia," they are heavily involved and are of utmost importance to be understood and studied in the modern healthcare industry. In simple terms, they are dermatological manifestations which result from systemic drug administration to patients. Since allopathy is influenced by the medicines and drugs provided to the patients, cutaneous skin eruptions are a common occurrence in recent times. It is a need of the hour to understand the causative factors for such skin eruptions and the correct management and handling of such disorders to provide better healthcare to patients. The withdrawal of the causative drug which induces the reaction plays a key role in treatment. The risk factors are to be thoroughly studied, and dosages must be in accordance with the patient's situation. They are some of the common public health problems. The age group which is affected is highly variable as people from all age groups can be affected. Those who are affected comprise approximately 10% of all hospitalized patients, and it is also observed in about 1-4% of people who are on multiple medications.

Safety of direct oral provocation test to delabel reported mild beta-lactam allergy in infants

BACKGROUND

Around 10% of people report a drug allergy and avoid some medications because of fear of allergic reactions. However, only after a proper diagnostic workup can some of these reactions be confirmed as allergic or nonallergic hypersensitivities. Beta-lactams (BLs) are the most common medication suspected of being involved in drug hypersensivity reactions (DHRs) in children. Recently, direct oral provocation tests (DPT) with BLs gained popularity within pediatric populations as a tool for delabeling children with suspected BL allergies. This study aimed to evaluate the safety of direct provocation tests in infants with mild cutaneous non-immediate reactions to BLs.

METHODS

The authors retrospectively analyzed the data of 151 infants between 2015 and 2022, referred for evaluating a suspected allergy to BLs that occurred before age 24 months.

RESULTS

The mean age of the children, including 55% male kids, at the suspected reaction was 15.9 months and the mean age at the time of the DPT was 39.6 months. In most cases, antibiotics were prescribed to treat common upper respiratory infections, such as acute otitis (54.3%) and acute tonsillitis (27.2%). Amoxicillin was considered the culprit drug in 62.9% of the cases, and the combination of amoxicillin-clavulanic acid in the case of 33.8% of children. The most frequent associated cutaneous clinical manifestations were maculopapular exanthema in 74.8% and delayed urticaria/angioedema in 25.2%. Of the 151 infants evaluated, parents of 149 infants agreed for a direct DPT, and only three had a positive test (2%). Symptoms resulting from the DPT were mild and easily treatable.

CONCLUSIONS

A direct DPT without prior tests is a safe and effective procedure to delabel BL allergy, even in infants. The authors wish to emphasize the importance of properly validating BL allergy suspicions by promoting appropriate diagnostic procedures in infants as, in most cases, DHRs can be excluded and there is no need for further therapeutic restrictions.

High-risk adverse drug reactions: consideration of limited dialysis therapy for toxic epidermal necrolysis (TEN)

Toxic epidermal necrolysis (TEN) is a rare but often lethal drug reaction involving the skin. Treatment is often centered around suppurative care, and the mortality rate remains unacceptably high, although the clinical and epidemiological features of TEN have been well documented for decades. Recent studies have placed an emphasis on certain medications in the pathophysiology of severe TEN, and our colleagues previously reported several cases of clinical improvement in TEN patients following hemodialysis. Here, we discuss the major considerations for initiating dialysis in TEN patients. By doing so, we hope to encourage others to explore this potential avenue for treating TEN, one of the most serious medical emergencies in the field of dermatology.

HLA-targeted sequencing reveals the pathogenic role of HLA-B*15:02/HLA-B*13:01 in albendazole-induced liver failure: a case report and a review of the literature

Drug-induced liver injury (DILI) is one of the serious adverse drug reactions (ADRs), which belongs to immune-mediated adverse drug reactions (IM-ADRs). As an essential health drug, albendazole has rarely been reported to cause serious liver damage. A young man in his 30 s developed severe jaundice, abnormal transaminases, and poor blood coagulation mechanism after taking albendazole, and eventually developed into severe liver failure. The patient was found heterozygous of HLA-B*15:02 and HLA-B*13:01 through HLA-targeted sequencing, which may have a pathogenic role in the disease. This case report summarizes his presentation, treatment, and prognosis. A useful summary of the diagnosis and associated genetic variant information is provided.

[Drug allergy: Fundamental aspects in diagnosis and treatment.]

BACKGROUND

Any substance used as a treatment for any disease can produce harmful or unpleasant events called adverse drug reactions (ADRs). They are due to inherent biological effects of the drug and are caused by immunological and non-immunological mechanisms.

OBJECTIVES

To describe the immunological mechanisms of hypersensitivity reactions (HSR) to drugs, their epidemiology, risk factors, classification, clinical manifestations, diagnosis, treatment, and prognosis.

METHODS

A review of the most current literature in English and Spanish was carried out, in the main databases, related to the HSR of various drug groups.

RESULTS

This study describes the terms used to define ADRs and HSRs, their classification and clinical manifestations, current diagnostic tools, treatment algorithms and prognosis of the most frequently used medications and with the highest prevalence of reported adverse events.

CONCLUSION

ADRs are a challenging entity, with a complex pathophysiology that has not been fully understood. Its approach requires a careful consideration since not all drugs have validated tests for their diagnosis nor a specific treatment. When indicating the use of any drug, the severity of the disease, the availability of other treatments and the potential risks of developing future adverse events should always be taken into consideration.

Unique structure of ozoralizumab, a trivalent anti-TNFα NANOBODY® compound, offers the potential advantage of mitigating the risk of immune complex-induced inflammation

Biologics have become an important component of treatment strategies for a variety of diseases, but the immunogenicity of large immune complexes (ICs) and aggregates of biologics may increase risk of adverse events is a concern for biologics and it remains unclear whether large ICs consisting of intrinsic antigen and therapeutic antibodies are actually involved in acute local inflammation such as injection site reaction (ISR). Ozoralizumab is a trivalent, bispecific NANOBODY^® compound that differs structurally from IgGs. Treatment with ozoralizumab has been shown to provide beneficial effects in the treatment of rheumatoid arthritis (RA) comparable to those obtained with other TNFα inhibitors. Very few ISRs (2%) have been reported after ozoralizumab administration, and the drug has been shown to have acceptable safety and tolerability. In this study, in order to elucidate the mechanism underlying the reduced incidence of ISRs associated with ozoralizumab administration, we investigated the stoichiometry of two TNFα inhibitors (ozoralizumab and adalimumab, an anti-TNFα IgG) ICs and the induction by these drugs of Fcγ receptor (FcγR)-mediated immune responses on neutrophils. Ozoralizumab-TNFα ICs are smaller than adalimumab-TNFα ICs and lack an Fc portion, thus mitigating FcγR-mediated immune responses on neutrophils. We also developed a model of anti-TNFα antibody-TNFα IC-induced subcutaneous inflammation and found that ozoralizumab-TNFα ICs do not induce any significant inflammation at injection sites. The results of our studies suggest that ozoralizumab is a promising candidate for the treatment of RA that entails a lower risk of the IC-mediated immune cell activation that leads to unwanted immune responses.

Anaphylaxis induced by intra-articular injection of chitosan: A case report and literature review

Generally, we consider chitosan being a safe, nontoxic natural polymer with wide clinical applications. However, allergic reactions caused by chitosan have been reported on rare occasions. We report here a case of allergy and perform a literature review.

Hypersensitivity reactions to small molecule drugs

Drug hypersensitivity reactions induced by small molecule drugs encompass a broad spectrum of adverse drug reactions with heterogeneous clinical presentations and mechanisms. These reactions are classified into allergic drug hypersensitivity reactions and non-allergic drug hypersensitivity reactions. At present, the hapten theory, pharmacological interaction with immune receptors (p-i) concept, altered peptide repertoire model, and altered T-cell receptor (TCR) repertoire model have been proposed to explain how small molecule drugs or their metabolites induce allergic drug hypersensitivity reactions. Meanwhile, direct activation of mast cells, provoking the complement system, stimulating or inhibiting inflammatory reaction-related enzymes, accumulating bradykinin, and/or triggering vascular hyperpermeability are considered as the main factors causing non-allergic drug hypersensitivity reactions. To date, many investigations have been performed to explore the underlying mechanisms involved in drug hypersensitivity reactions and to search for predictive and preventive methods in both clinical and non-clinical trials. However, validated methods for predicting and diagnosing hypersensitivity reactions to small molecule drugs and deeper insight into the relevant underlying mechanisms are still limited.

Case Report: Cannabidiol-Induced Skin Rash: A Case Series and Key Recommendations

Cannabidiol (CBD) is a non-psychotomimetic constituent of the Cannabis plant, with potential therapeutic properties for many physical and neuropsychiatric conditions. Isolated CBD has been suggested to have favorable safety and tolerability. Although CBD-related rash is described, few case reports are well documented in the literature, and usually, CBD was used concomitantly with other medications. Thus, we report four women who presented a skin rash after ongoing CBD use. Other causes of these skin rashes were ruled out after conducting an extensive viral and serological detection panel, and three patients had their lesions biopsied. Two patients were re-exposed to the vehicle (MCT) without developing a new skin rash. Therefore, clinicians must be aware of this potential adverse effect of CBD use.

A Novel Method for the Syntheses of Imidazo-Thiadiazoles as Potential Antioxidants and Anti-Inflammatory Agents

BACKGROUND

A literature survey revealed that many imidazo-thiadiazole molecules were used as key intermediates for the development of novel drugs. The synthesized imidazo-thiadiazole derivatives were tested for their in vitro antioxidant and anti-inflammatory properties. The purpose of this research paper is to provide readers with information regarding diseases caused by free radicals.

OBJECTIVE

The objective of this study is to develop novel antioxidant and anti-inflammatory drugs.

METHODS

Imidazo-thiadiazole derivatives 5a-f were synthesized through cyclo-condensation reactions in two steps. First, the synthesis of 2-amino-thiadiazole derivatives from substituted aromatic carboxylic acids and thiosemicarbazide by using POCl₃ as a solvent as well as a catalyst was performed. In the next step, imidazo-thiadiazoles were prepared from 2-amino-thiadiazole derivatives with appropriate α-haloketones in the presence of polyethylene glycol-300 (PEG-300) as a green solvent. These imidazo- thiadiazole derivatives were prepared by using a novel method. The synthesized compounds were in vitro tested for their antioxidant and anti-inflammatory activities.

RESULTS

In vitro evaluation report showed that nearly all molecules possess potential antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), superoxide radical (SOR), and hydrogen peroxide (H₂O₂) radical scavenging activity. Most of the imidazo-thiadiazole derivatives have shown significant anti-inflammatory activity as compared to diclofenac sodium as a reference standard.

CONCLUSION

In the search for novel therapies to treat inflammation and oxidation, we have made efforts to develop anti-inflammatory and antioxidant agents with a preeminent activity. Imidazo-thiadiazoles 5a, 5e as well as 5f showed potential anti-inflammatory activity. All tested imidazo-thiadiazole deriv-atives (5a-f) showed potential antioxidant activity against one more radical scavenging species as com-pared to ascorbic acid as the reference standard. Thus, imidazo-thiadiazole derivatives constitute an interesting template for the design and development of new antioxidant as well as anti-inflammatory agents.

Recent update on the management of anaphylaxis

Anaphylaxis is a life-threatening systemic allergic reaction presenting various clinical manifestations. Its prevalence has increased in almost all age groups and both sexes. Food, venom, and drugs are major causes in both children and adults; a higher prevalence of food-induced anaphylaxis is noted in children, while a higher prevalence of drug-induced anaphylaxis is noted in adults. The pathogenic mechanism is mediated by immunologic and nonimmunologic mechanisms, where mast cells and basophils are key cells that release mediators. A diagnosis of anaphylaxis is mainly based on clinical symptoms and physical findings; however, an increased serum tryptase level is a useful biomarker. Epinephrine is the first-line drug to treat acute symptoms, and an epinephrine auto-injector should be prescribed for each patient. Antihistamines and systemic corticosteroids are used to relieve symptoms. This review updates current issues in the management of anaphylaxis as well as the new guidelines for proper diagnosis and treatment.

Clinical Application of Pharmacogenetic Markers in the Treatment of Dermatologic Pathologies

Dermatologic pathologies are the fourth most common cause of non-fatal disease worldwide; however, they produce a psychosocial, economic, and occupational impact equal to or greater than other chronic conditions. The most prevalent are actinic keratosis, followed by basal-cell carcinoma, in a lesser proportion acne vulgaris, psoriasis, and hidradenitis suppurativa, among others, and more rarely dermatitis herpetiformis. To treat actinic keratosis and basal-cell carcinoma, 5-fluorouracil (5-FU) 0.5% is administered topically with good results, although in certain patients it produces severe toxicity. On the other hand, dapsone is a drug commonly used in inflammatory skin conditions such as dermatitis herpetiformis; however, it occasionally causes hemolytic anemia. Additionally, biologic drugs indicated for the treatment of moderate-to-severe psoriasis and hidradenitis suppurativa have proved to be effective and safe; nevertheless, a small percentage of patients do not respond to treatment with biologics in the long term or they are ineffective. This interindividual variability in response may be due to alterations in genes that encode proteins involved in the pathologic environment of the disease or the mechanism of action of the medication. Pharmacogenetics studies the relationship between genetic variations and drug response, which is useful for the early identification of non-responsive patients and those with a higher risk of developing toxicity upon treatment. This review describes the pharmacogenetic recommendations with the strongest evidence at present for the treatments used in dermatology, highlighting those included in clinical practice guides. Currently, we could only find pharmacogenetic clinical guidelines for 5-FU. However, the summary of product characteristics for dapsone contains a pharmacogenetic recommendation from the United States Food and Drug Administration. Finally, there is an enormous amount of information from pharmacogenetic studies in patients with dermatologic pathologies (mainly psoriasis) treated with biologic therapies, but they need to be validated in order to be included in clinical practice guides.

Carbamazepine drug reaction involving high fevers during the COVID-19 era

Carbamazepine has demonstrated anticonvulsant properties and is used for a variety of indications in psychiatry and neurology. Total daily doses typically range from 200 to 1200 mg/d, generally divided into 2 doses. Carbamazepine has a broad side-effect profile but is not typically thought to produce high fevers in the absence of a hypersensitivity syndrome. This is a case of a probable adverse drug reaction to carbamazepine consisting of fever without severe major organ involvement. In this instance, a patient in a manic episode with psychotic features was briefly transferred to a COVID-19 unit to rule out coronavirus infection before the fever resolved.

Sodium aescinate and its bioactive components induce degranulation via oxidative stress in RBL-2H3 mast cells

Sodium aescinate (SA) is a vital salt of sodium escin from Aesculus wilsonii Rehd seeds. SA injection (SAI) has received great success in treating cerebral edema, venous reflux disease and other inflammatory conditions. Recently, high incidences of immediate hypersensitivity reactions were reported after SA infusion, which raised questions on safety and risk associated with its clinical application. This study was designed to check whether SAI and its four components induce degranulation using RBL-2H3 mast cells. For this purpose, we evaluated different treatment levels of SAI (20, 40, 60, 80 and 100 μg ml^-1) and its four characteristic components, SA-A, SA-B, SA-C and SA-D, at 60 μg ml^-1 in different tests including cell viability test, β-hexosaminidase and histamine assays, oxidative stress indices, apoptosis analysis and intracellular calcium ions in RBL-2H3 cells. Our results demonstrated that SAI at 80 μg ml^-1 and 100 μg ml^-1, and its two components (SA-B and SA-D) at 60 μg ml^-1 were responsible for disturbing cell morphology and cell viability, elevated levels of β-hexosaminidase, histamine, modulation of oxidative stress indices, induced apoptosis and increase in intracellular calcium ions in RBL-2H3 cells, when compared with the control. Our results demonstrated for the first time that SAI was more likely to induce immediate hypersensitivity reactions attributable to degranulation via oxidative stress caused by SA-B and SA-D components. These results would not only be useful for the safety of end user but also for the industry to improve the quality of SA infusion.

Severe cutaneous adverse drug reactions manifesting as Stevens-Johnson syndrome and toxic epidermal necrolysis reported to the national pharmacovigilance center in Nigeria: a database review from 2004 to 2017

Background:

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe cutaneous adverse reactions (SCARs). There is scant literature on the characteristics and causes of these conditions among the Nigerian population. Here, we describe the epidemiology, associated morbidity and mortality, and culpable drugs in SJS and TEN cases using the National Pharmacovigilance (NPC) database in Nigeria.

Methods:

A retrospective review of the NPC database was done to analyze SJS and TEN cases reported over a period of 14 years. Annual reports, age and sex of patients, type of reporter, suspects and concomitant drugs, time to onset (TTO) of the reactions, and outcome of SJS and TEN were evaluated.

Results:

The NPC received a total of 24,015 adverse drug reaction (ADR) reports. SJS and TEN accounted for 284 (0.1%) of the total reports, of which 254 (89.4%) were SJS and the remainder were TEN. Females (n = 184, 64.8%) and individuals aged 19–40 years (n = 181, 63.7%) were the most affected by SJS and TEN. Antiretrovirals, followed by antibiotics, were the most common drug classes reported to cause SJS and TEN, with nevirapine (n = 174, 40.7%) and co-trimoxazole (n = 143, 33.5%) being the most widely implicated drugs. Among patients with reported outcomes, 73 (28.7%) SJS and 3 (10.0%) TEN cases recovered without sequelae, at the time of reporting. Severity of the SCAR was reported for only 171 (69.0%) cases, of which 12 (4.7%) and 8 (26.7%) resulted in death (Grade 5) among SJS and TEN cases, respectively.

Conclusions:

Antiretroviral and antibiotics were the commonly reported offending group of drugs for SJS and TEN cases. Nevirapine and co-trimoxazole were the commonly reported suspect drugs. SJS and TEN were reported most frequently in females and in patients aged 19–40 years, indicating that drug surveillance and counseling in these groups of patients may be beneficial.