Drug Challenge Tests With General Anesthetics: Predictive Value of Skin Tests.

BACKGROUND: The study of perioperative drug reactions remains a major challenge for both diagnosis and therapy. The lack of a standard assessment of allergy to general anesthetics and of data establishing the true value of skin tests for most drugs used in induction and maintenance of anesthesia, as well as the lack of commercially available reagents for in vitro tests, renders the study of these reactions problematic. The aims of this study were to provide a diagnostic protocol for drug challenge testing with general anesthetics, to establish an etiological diagnosis that is as specific as possible, and to determine the predictive value of skin tests. METHODS: Twenty-nine patients with perioperative drug reactions were included in the study from November 2008 to December 2018. RESULTS: We confirmed the high negative predictive value of the tests (96%-100%) in the case of propofol, rocuronium, and fentanyl. To our knowledge, this is the first study to describe drug challenge testing with general anesthetics and, therefore, to establish the true negative predictive value of skin tests, which leads to a definitive diagnosis and safer surgery. CONCLUSIONS: After assessing risks and benefits and considering the importance of this group of drugs, we conclude that drug challenge testing with general anesthetics is necessary. We propose a protocol for perioperative drug reactions that enables us to make a highly accurate etiological diagnosis with minimum risk for the patient.

Sequential combined therapy with omalizumab and rituximab: a new approach to severe atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a common chronic skin disease, and a significant percentage of AD patients have severe forms. Inflammation based on type 2 helper T cells (T(H)2), autoantibodies, and CD8+ T cells could play a relevant role in this disease. When the patient requires systemic immunosuppressors for disease control, side effects are frequent. We propose a sequential therapeutic strategy with 2 monoclonal antibodies, omalizumab (anti-immunoglobulin [Ig] E) and rituximab (anti-CD20), which might induce clinical benefit with few side effects in selected individuals with AD. METHODS: We report 6 cases of severe AD refractory to conventional therapy. The patients underwent sequential switch therapy with omalizumab and rituximab. Clinical response was assessed by means of the decrease in body surface affected. Immunological parameters and side effects were also monitored. RESULTS: Four patients received omalizumab before a high-dose cycle of rituximab. In the case of recurrences, either low-dose cycles of rituximab or omalizumab were administered. A long-term clinical benefit was observed in 3 out of 4 patients. Two patients first received high-dose rituximab followed by either low-dose rituximab or omalizumab, and one of them achieved a response at 17 months. No severe side effects were recorded. Serum IgE level and B-cell counts decreased with therapy, the latter returning to baseline levels 10 to 11 months after treatment. Specific antibody responses remained protective during the study. CONCLUSIONS: With our proposed switch therapy, 4 out of 6 patients achieved a dramatic clinical improvement. This novel strategy targets different arms of the immune response and might be a good alternative for patients with severe AD.