SummaryBackground Cases of severe drug hypersensitivity, demonstrating a variable spectrum of cutaneous and systemic involvement, are reported under various names, especially drug reaction with eosinophilia and systemic symptoms (DRESS). Case definition and overlap with other severe cutaneous adverse reactions (SCAR) are debated. Objectives To analyse the spectrum of signs and symptoms of DRESS and distribution of causative drugs in a large multicentre series. Results The male/female ratio was 0Á80; females were borderline significantly younger than males. Next to the ubiquitous exanthema, the main features were eosinophilia (95%), visceral involvement (91%), high fever (90%), atypical lymphocytes (67%), mild mucosal involvement (56%) and lymphadenopathy (54%). The reaction was protracted in all but two patients; two patients died during the acute phase. Drug causality was plausible in 88% of cases. Antiepileptic drugs were involved in 35%, allopurinol in 18%, antimicrobial sulfonamides and dapsone in 12% and other antibiotics in 11%. The median time interval after drug intake was 22 days (interquartile range 17-31) for all drugs with (very) probable causality, with differences between drugs. Conclusion This prospective observational study supports the hypothesis that DRESS is an original phenotype among SCAR in terms of clinical and biological characteristics, causative drugs, and time relation. The diversity of causative drugs was rather limited, and mortality was lower than that suggested by prior publications.

Background: A wide range of diseases or reactions can cause pustular eruptions of the skin. In this spectrum there seems to be a subgroup with characteristic clinical features and a typical course which is mostly caused by drugs for which the term acute generalized exanthematous pustulosis (AGEP) has been established. Objective: To describe the clinical features of AGEP. Methods: The authors’ experience from a multinational epidemiological study on severe cutaneous adverse reactions and a comprehensive review of the literature were used to provide an overview of the disease and it’s possible causes. An algorithm for validating cases which was established for this study is also presented. Results: AGEP typically presents with at least dozens of non follicular sterile pustules occurring on a diffuse, edematous erythema predominalty in the folds and/or on the face. Fever and elevated blood neutrophils are common. Histopathology typically shows spongiform subcorneal and/or intraepidermal pustules, a marked edema of the papillary dermis, and eventually vasculitis, eosinophils and/or focal necrosis of keratinocytes. Onset is acute, most often following drug intake, but viral infections can also trigger the disease. Pustules resolve spontaneously in less than 15 days. Conclusion: The diagnosis AGEP should be considered in cases of acute pustular rashes and detection of the causative drug should be strived for. Knowledge of the clinical features and usual course of this disease can often prevent unnecessary therapeutical measures.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but severe cutaneous adverse reactions (SCAR) related to a variety of medications. They have a significant public health impact because of high mortality and morbidity. A multinational case-control study conducted in Europe between 1997 and 2001 evaluated the risk of medications to induce SCAR. Cases were actively detected through a hospital network covering more than 100 million inhabitants. Three hospitalized patients per case matched on age, gender, and date of interview were enrolled as controls. After validation by an expert committee blinded to exposures, 379 SCAR cases and 1,505 controls were included. Among drugs recently introduced into the market, strong associations were documented for nevirapine (relative risk (RR)>22) and lamotrigine (RR>14), and weaker associations for sertraline (RR=11 [2.7-46]), pantoprazole (RR=18 [3.9-85]), and tramadol (RR=20 [4.4-93]). Strong associations were confirmed for anti-infective sulfonamides, allopurinol, carbamazapine, phenobarbital, phenytoin, and oxicam-NSAIDs , with some changes in relative numbers of exposed cases. Thus, many cases were still related to a few "old" drugs with a known high risk. Risk was restricted to the first few weeks of drug intake. The use of such drugs as first-line therapies should be considered carefully, especially when safer alternative treatments exist. A number of widely used drugs did not show any risk for SJS and TEN.