MT-CO1 and anaphylaxis: In contrast, tolerance to NSAIDs and other COXi was more frequent among males (p = 0.02), in patients with anaphylaxis caused by Hymenoptera venom (p = 0.02), among individuals who had skin lesions due to mastocytosis (p = 0.01), and in cases that had no baseline pruritus (p = 0.006).