Treatment with IL5-/IL-5 receptor antagonists in drug reaction with eosinophilia and systemic symptoms (DRESS).

Purpose: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe delayed drug hypersensitivity reaction with exanthema, eosinophilia, and organ manifestations. After culprit drug withdrawal, systemic corticosteroids (CS) are the most widely used treatment, often requiring high doses for months. Blocking the IL-5/IL­5 receptor axis with mepolizumab, reslizumab, and benralizumab is a promising targeted treatment with a good safety profile and no immunosuppressive effect. The aim of this study is to summarize current experience with the anti-IL5/IL-5-receptor therapy in DRESS. Methods: A retrospective analysis of all patients diagnosed with DRESS and treated with mepolizumab, reslizumab, or benralizumab in DRESS was performed. In addition, a PubMed-Medline search for publications on DRESS with anti-IL-5/IL­5 receptor treatment was performed. Results: Of the 14 cases identified, 6 patients were treated with mepolizumab, 6 with benralizumab, 1 patient with reslizumab, and 1 patient was switched from benralizumab to mepolizumab. The main indication for an IL­5 blockade was a therapy-refractory course (7/14 [50.0%]), recurrent relapses (3/14 [21.4%]), and severe organ dysfunction (2/14 [14.3%]). In 13/14 (93%) cases, a rapid clinical improvement with suppression of eosinophilia and reduction of CS could be achieved. In all but two cases under mepolizumab (dose 100-600 mg) or reslizumab (dose according to body weight), two or more doses were necessary until resolution of DRESS. In 4/7 cases under benralizumab, a single 30 mg dose was sufficient. Conclusion: Blockade of the IL-5/IL­5 receptor axis appears to be a promising treatment in DRESS with fast clinical improvement, which may allow more rapid reduction of CS, and a good safety profile. In addition, a summary of recommendations on when to use blockade of the IL-5/IL­5 receptor axis in DRESS treatment is provided.

75% negative skin test results in patients with suspected hypersensitivity to beta-lactam antibiotics: Influencing factors and interpretation of test results.

BACKGROUND: The diagnostic approach for beta-lactam (BL) drug hypersensitivity reactions (DHR) is based on the history, clinical signs, skin tests (ST), in vitro tests, and drug provocation tests (DPT). The aim of this study was to assess the performance of an allergy workup with ST in a real-world use. METHODS: In this cross-sectional study the rate of positive ST in subjects with suspected DHR to penicillins and cephalosporins was investigated. Of special interest were correlations of ST positivity: 1) to the time intervals between index reaction and the allergic work-up, 2) time interval from drug exposure to the onset of signs, 3) pattern of manifestation in delayed DHR and involvement of test area in the index reaction, and 4) potential advantage of patch testing in delayed DHR. RESULTS: 175 patients were included between January 2018 and April 2019 (63.4% female), 45 (25.7%) with immediate DHR manifestation and 130 with delayed DHR manifestation (74.3%). A total of 44 patients (25.1%) had a positive ST (immediate DHR 37.8% versus 20.0% in delayed DHR). ST positivity decreased in both groups after 3 years from 47.8% [95%CI 29.2-67] to 23.5% [95%CI 9.6-47.3] in immediate DHR and 23.0% [95%CI 15-4-32.9] to 12.9% [95%CI 5.1-28.9] in delayed DHR. The proportion of positive ST was higher in patients with more severe forms of delayed DHR, and in subjects with a shorter latency period of onset of symptoms after drug exposure: 0-3d: 29.5% [95%CI 19.6-41.9] vs. >3d: 11.6% [95%CI 6.0-21.2]). No sensitization was shown in delayed urticaria or angioedema. ST done outside the skin area involved during the index reaction were negative in all cases (0/38 vs. 26/84 in cases with involved area). The combination of patch test and intradermal test (IDT) revealed an additional positive result in 2/77 cases. Additional in vitro testing reduced the proportion of negative test results to 72%. CONCLUSION: In most patients with negative test results, we could not clarify the cause of the BL-associated adverse events even with further investigations (including DPT). How to prevent new drug-induced adverse events in such patients has hardly been investigated yet. Corresponding cohort studies could improve the data situation.