Impact of systemic to topical steroids switch on the outcome of drug reaction with eosinophilia and systemic symptoms (DRESS): A monocenter retrospective study of 20 cases.

BACKGROUND: There is no consensus on the treatment of drug reaction with eosinophilia and systemic symptoms (DRESS). At our center, systemic steroids (SS) are used for severe cases while topical steroids (TS) are used for mild and moderate forms. OBJECTIVES: To investigate the short-term outcome for patients with DRESS receiving SS as first-line therapy before being transferred to our department and then switched to TS after admission. METHODS: A retrospective monocenter study in DRESS patients (RegiSCAR score≥4) transferred to our dermatology department from a different setting between 07/2012 and 06/2018 and who had received SS before being transferred. Epidemiological, clinical and laboratory data were collected, as well as details of treatment modalities and outcome. RESULTS: Twenty patients were included. On admission to our department, 4 were assessed as having severe DRESS and continued on SS, while 16 were assessed as mild/moderate DRESS and were switched to TS. Among these 16 patients, the outcome on TS was favorable for 12 and quickly unfavorable for 4, who had to be switched back to SS. Retrospective analysis of the initial data (before transfer) showed that these 4 patients had previously had a greater number of severity criteria than the other 12. CONCLUSION: Caution is needed not only when deciding to initiate SS in DRESS but also on withdrawal of these drugs. Our series suggests that when SS are used as first-line therapy in DRESS patients with initial severity criteria, they should not be withdrawn quickly for a switch to TS, even where progression appears favorable, due to the risk of relapse.

A multiplex-PCR assay for identification of the quarantine plant pathogen Xanthomonas axonopodis pv. phaseoli.

In this study we developed an algorithm to screen for all exact molecular signatures of the quarantine pathogen Xanthomonas axonopodis pv. phaseoli (Xap), based on available data of the presence or absence of virulence-associated genes. The simultaneous presence of genes avrBsT and xopL is specific to Xap. Therefore we developed a multiplex PCR assay targeting avrBsT and xopL for the molecular identification of Xap. The specificity of this multiplex was validated by comparison to that of other molecular identification assays aimed at Xap, on a wide collection of reference strains. This multiplex was further validated on a blind collection of Xanthomonas isolates for which pathogenicity was assayed by stem wounding and by dipping leaves into calibrated inocula. This multiplex was combined to the previously described X4c/X4e molecular identification assay for Xap. Such a combination enables the molecular identification of all strains of Xanthomonas pathogenic on bean. Results also show that assay by stem wounding does not give reliable results in the case of Xap, and that pathogenicity assays by dipping should be preferred.