Recurrent Toxic Epidermal Necrolysis Secondary to Iopromide Contrast:

Changing patterns in the epidemiology of drug allergy

Drug allergy (DA) remains a complex and unaddressed problem worldwide that often deprives patients of optimal medication choices and places them at risk for life-threatening reactions. Underdiagnosis and overdiagnosis are common and due to the lack of standardized definitions and biomarkers. The true burden of DA is unknown, and recent efforts in data gathering through electronic medical records are starting to provide emerging patterns around the world. Ten percent of the general population engaged in health care claim to have a DA, and the most common label is penicillin allergy. Up to 20% of emergency room visits for anaphylaxis are due to DA and 15%-20% of hospitalized patients report DA. It is estimated that DA will increase based on the availability and use of new and targeted antibiotics, vaccines, chemotherapies, biologicals, and small molecules, which are aimed at improving patient's options and quality of life. Global and regional variations in the prevalence of diseases such as human immunodeficiency virus and mycobacterial diseases, and the drugs used to treat these infections have an impact on DA. The aim of this review is to provide an update on the global impact of DA by presenting emerging data on drug epidemiology in adult and pediatric populations.

An individual patient data meta-analysis of wound care in patients with toxic epidermal necrolysis

Toxic epidermal necrolysis (TEN) involves extensive mucocutaneous loss, and care is supportive. The approach to wound care includes surgical debridement or using dressings while leaving the epidermis intact. Robust evidence for either approach is lacking. We compared surgical debridement to the use of dressings while leaving the epidermis in situ (referred to hereon as dressings) in adult patients with TEN. The primary outcome assessed was mortality. The secondary outcome was time to re-epithelialisation. The impact of medications was evaluated. An individual patient data (IPD) systematic review and meta-analysis was undertaken. A random effects meta-analysis and survival analysis for IPD data examined mortality, re-epithelisation time and the effect of systemic medications. The quality of evidence was rated per the Grading of Recommendations Assessment, Development and Evaluation (GRADE). PROSPERO: CRD42021266611 Fifty-four studies involving 227 patients were included in the systematic review and meta-analysis, with a GRADE from very low to moderate. There was no difference in survival in patients who had surgical debridement or dressings (univariate: p = 0.91, multivariate: p = 0.31). Patients who received dressings re-epithelialised faster than patients who underwent debridement (multivariate HR: 1.96 [1.09-3.51], p = 0.023). Intravenous immunoglobulin (univariate HR: 0.21 [0.09-0.45], p < 0.001; multivariate HR: 0.22 [0.09-0.53], p < 0.001) and cyclosporin significantly reduced mortality (univariate HR: 0.09 [0.01-0.96], p = 0.046; multivariate HR: 0.06 [0.01-0.73], p = 0.028) irrespective of the wound care. This study supports the expert consensus of the dermatology hospitalists, that wound care in patients with TEN should be supportive with the epidermis left intact and supported with dressings, which leads to faster re-epithelialisation.

Current Epidemiology and Management of Radiocontrast-Associated Acute- and Delayed-Onset Hypersensitivity: A Review of the Literature

Radiocontrast-associated acute-onset hypersensitivity reactions now occur less frequently than before 1990, when high-osmolar, ionic, radiocontrast agents were widely used. Premedication with corticosteroids and antihistamines does not reliably prevent recurrent low-osmolar radiocontrast-associated acute hypersensitivity reactions. Corticosteroid prophylaxis for acute hypersensitivity currently causes more morbidity than benefit. The specific radiocontrast agent that is associated with a patient's adverse reaction must be displayed in the drug intolerance or drug "allergy" field of their electronic health record to enable effective management and prevention of future reactions. The term iodine allergy should never be used in the context of radiocontrast-associated adverse reactions because it leads to poorer clinical outcomes. The time to onset of the reaction and the nature of the reaction must be noted in enough detail in the drug intolerance comment fields in the electronic health record to determine the potential mechanism for the reaction and to enable selection of the appropriate radiocontrast material for future exposures. Most individuals with a history of radiocontrast agent hypersensitivity can be effectively managed by selecting an alternative radiocontrast agent, without any premedication. Radiology Departments, catheterization laboratories, and all physicians who use parenteral radiocontrast media must have management plans in place to treat severe acute reactions when they occur. Patients should be informed that delayed-onset reactions, mostly benign rashes within one week of exposure, are as common or more common than acute reactions. Future radiocontrast-associated acute and delayed-onset reactions can be minimized, but never completely avoided, by using an appropriate alternative agent.

Recurrent Toxic Epidermal Necrolysis Syndrome: A Report of Two Cases

An 81-year-old male and a 47-year-old female experienced recurrent severe bullous dermatosis secondary to an intake of drugs and alternative medicines indicated for arthralgias. The first patient had previously presented with Stevens–Johnson/toxic epidermal necrolysis (TEN) overlap syndrome in 2007 secondary to ingestion of trimethoprim/sulfamethoxazole indicated for a urinary tract infection; 6 years later, he presented with the same syndrome 2 days after ingestion of oral naproxen tablets 250 mg twice daily. The second patient had presented 5 years previously with TEN after receiving trimethoprim/sulfamethoxazole. In 2014, she presented with arthralgias and received a xenobiotic oral called ‘miracle pills’ (dosage is unknown); 3 weeks later, she again experienced TEN. Both patients were treated with intravenous immunoglobulin 400 mg/kg/day; duration of treatment was 5 days for the first patient and 3 days for the second. However, the male patient died from severe sepsis; the female patient experienced a favorable outcome. There are many risk factors for the development of cutaneous adverse drug reactions; a history of allergic reactions is one important risk factor, and both patients had it. This article reviews the scientific literature on this topic and analyzes the possible causes, including infectious processes, immunological defects, and immunogenetic factors.

Hypersensitivity to contrast media and dyes

This article updates current knowledge on hypersensitivity reactions to diagnostic contrast media and dyes. After application of a single iodinated radiocontrast medium (RCM), gadolinium-based contrast medium, fluorescein, or a blue dye, a hypersensitivity reaction is not a common finding; however, because of the high and still increasing frequency of those procedures, patients who have experienced severe reactions are nevertheless frequently encountered in allergy departments. Evidence on allergologic testing and management is best for iodinated RCM, limited for blue dyes, and insufficient for fluorescein. Skin tests can be helpful in the diagnosis of patients with hypersensitivity reactions to these compounds.