CRP and anaphylaxis: The C-reactive protein (CRP) was elevated (61.6 mg/L), consistent with infection. Following the onset of anaphylaxis, mast cell tryptase levels were measured and showed a rise from baseline (3.1 μg/L) to a peak of 13.4 μg/L at three hours, then declined at 12 hours, a pattern strongly supportive of mast cell activation and anaphylaxis.