Proton pump inhibitors (PPI) are widely used for the treatment of peptic ulcer, but cases of anaphylactic reactions have rarely been described. We present a patient who experienced an episode of urticaria 30 minutes after oral intake of an omeprazole capsule. Skin prick tests to omeprazole, pantoprazole and lansoprazole were positive. Challenge test with lansoprazole was carried out and within 45 minutes the patient developed urticaria, facial edema, vomiting, and hypotension. Oral challenge with other imidazole derivatives (ketoconazole, cimetidine, metronidazole) were carried out with good tolerance. Serum tryptase levels determined 3 hours after the adverse reaction to lansoprazole were elevated. Specific IgE to PPI were not detected by an enzyme-linked immunosorbent assay technique. The clinical findings, positive skin prick test to PPI and elevated serum tryptase levels suggest that an IgE-mediated mechanism was implicated in the reactions to both omeprazole and lansoprazole. Skin prick tests may be a useful tool for detecting patients sensitized to PPI. An experimental protocol was used to detect specific IgE antibodies against PPI, which may explain RAST negativity. The previous findings suggest that cross-reactivity between PPI exists, but not with other imidazoles.
The objective of this work is to report the MRI findings in patients with radiation myelopathy due to accidental local over-irradiation syndrome. Eight patients (seven males and one female) were suffering from over-irradiation syndrome as a result of treatments from a malfunctioning linear electron accelerator. The mean accidental estimated dose was 136 Gy delivered to the "open-neck" (seven cases) and to the thoracic wall (one case), during a mean of 5.4 sessions (range 1-9 sessions). Paresthesia and weakness in the upper extremities were the earliest symptoms (87.5 %), with evolution to paralysis in all patients. No patient is alive (mean survival time 64 days). In all cases MRI was negative for neurologic lesions in the acute phase ( < 90 days from irradiation; Radiation Therapy Oncology Group scoring system). Late signs of radiation myelitis manifested as high-intensity signals on T2-weighted images in three patients, and as Gd-DTPA enhancement of T1-weighted images in one case. Autopsies performed on four patients who died in acute phase showed morphologic alterations in white matter: edema in 75 %, and necrosis and glial reaction as well as obliterative vasculitis in all cases. In cases of over-irradiation, MRI may be normal in acute phase even if the patients have severe neurologic deficit, as positive MRI findings appear only in delayed radiation myelitis.
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