Idiopathic Mast Cell Activation Syndrome With Associated Salicylate Intolerance

Abstract

Idiopathic mast cell activation syndrome can be a rare cause for chronic abdominal pain in children. It remains a diagnosis by exclusion that can be particularly challenging due to the vast variety of possible clinical manifestations. We present a 13-year-old boy who suffered from a multitude of unspecific complaints over a long period of time. In this case, an assessment of mast cell-derived metabolites and immunohistochemical analysis of bioptic specimen was worthwhile. After ruling out, primary (oncologic) and secondary causes for mast cell activation, pharmacologic treatment adapted to the patient's salicylate intolerance resulted in a major relief of symptoms.

Keywords: abdominal pain; endoscopically guided lavage; idiopathic mast cell activation syndrome; mast cell activation; mastocytosis; salicylate intolerance.

Figure 1

Macroscopic findings in gastroscopy and colonoscopy. Follicular hyperplasia in upper and lower intestinal tract.

Figure 2

Immunohistochemical findings demonstrating mature mast cell infiltration. Dense stromal mast cell infiltrations of up to 60/HPF [staining for CD117⁺ (left), tryptase (right), and CD25⁻ (lower left image)]; mature type; cKIT-D816V mutation negative; normal crypt architecture; no eosinophils.