Interstitial cystitis and bladder mastocytosis in a woman with chronic urticaria.

A patient with chronic urticaria and angioedema developed endoscopically confirmed interstitial cystitis. Bladder biopsy revealed bladder mastocytosis with > 60 mast cells/mm2 (normal < 10) in the detrusor and submucosa. Most of the mast cells were activated and degranulated. The occurrence of IC in a patient with urticaria and angioedema, diseases both associated with mast cell pathophysiology, supports the role of mast cells in interstitial cystitis.