Does sensitization by SARS-CoV-2 immune complexes trigger DRESS syndrome?

Exploring recent advances in drugs severe cutaneous adverse reactions immunopathology

Severe cutaneous adverse reactions to drugs (SCARs) are rare but life-threatening delayed allergies. While they primarily affect the skin, they can also affect internal organs. Accordingly, they present with diverse clinical symptoms that vary not only between SCARs subtypes but also among patients. Despite the availability of topical and systemic treatments, these only address the symptoms and not the cause. To develop more effective therapies, it is necessary to elucidate the complexity of the pathophysiology of SCARs in relation to their severity. In line with the new type IV hypersensitivity reactions nomenclature proposed by the European Academy of Allergy and Clinical Immunology (EAACI), this review highlights the current insights into the intricate immune mechanisms engaged, the interplay between the culprit drug and genetic predisposition in drug presentation mechanisms, but also how external factors, such as viruses, are implicated in SCARs. Their relevance to the development of targeted medicine is also discussed.

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms. Part I. Epidemiology, pathogenesis, clinicopathological features, and prognosis

Drug-induced hypersensitivity syndrome (DiHS), also known as drug reaction with eosinophilia and systemic symptoms (DRESS), is a severe cutaneous adverse reaction (SCAR) characterized by an exanthem, fever, and hematologic and visceral organ involvement. Anticonvulsants, antibiotics, and allopurinol are the most common triggers. The pathogenesis involves a complex interplay between drugs, viruses, and the immune system primarily mediated by T-cells. DiHS/DRESS typically presents with a morbilliform eruption 2-6 weeks after drug exposure, and is associated with significant morbidity, mortality, and risk of relapse. Long-term sequelae primarily relate to organ dysfunction and autoimmune diseases. Part I of this continuing medical education activity on DiHS/DRESS provides an update on epidemiology, novel insights into pathogenesis, and a description of clinicopathological features and prognosis.

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS): Focus on the Pathophysiological and Diagnostic Role of Viruses

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a heterogeneous, multiorgan and potentially life-threatening drug-hypersensitivity reaction (DHR) that occurs several days or weeks after drug initiation or discontinuation. DHRs constitute an emerging issue for public health, due to population aging, growing multi-organ morbidity, and subsequent enhanced drug prescriptions. DRESS has more consistently been associated with anticonvulsants, allopurinol and antibiotics, such as sulphonamides and vancomycin, although new drugs are increasingly reported as culprit agents. Reactivation of latent infectious agents such as viruses (especially Herpesviridae) plays a key role in prompting and sustaining aberrant T-cell and eosinophil responses to drugs and pathogens, ultimately causing organ damage. However, the boundaries of the impact of viral agents in the pathophysiology of DRESS are still ill-defined. Along with growing awareness of the multifaceted aspects of immune perturbation caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the ongoing SARS-CoV-2-related disease (COVID-19) pandemic, novel interest has been sparked towards DRESS and the potential interactions among antiviral and anti-drug inflammatory responses. In this review, we summarised the most recent evidence on pathophysiological mechanisms, diagnostic approaches, and clinical management of DRESS with the aim of increasing awareness on this syndrome and possibly suggesting clues for future research in this field.