Eosinophilic cystitis: an uncommon form of cystitis.

Since 1959, 39 cases of eosinophilic cystitis have been reported in the literature. Eosinophilic cystitis is a rare form of allergic cystitis in patients who usually have a strong allergic history. It mimics other forms of intractable cystitis, such as interstitial cystitis, tuberculosis and bladder neoplasms. It is caused by various antigens that form immune complexes at the bladder level and stimulate eosinophilic infiltration. Food allergens, medications, topical agents and parasites have been implicated. The diagnosis is made by excluding all other forms of cystitis.