Persistence of delayed hypersensitivity following transurethral collagen injection for recurrent urinary stress incontinence.

Transurethral collagen injection is both safe and effective when used for the treatment of genuine stress urinary incontinence. It is associated with a minimal inflammatory response, and virtually no foreign body reaction. Most allergic reactions occur within 72 hours of treatment (immediate hypersensitivity). Although uncommon, delayed hypersensitivity reactions may occur and it is advisable to administer a collagen skin test 30 days prior to the procedure. Adverse effects may cause long-term sequelae, such as severe trigonal tenderness, urgency, frequency, hematuria, urinary retention and persistent stress urinary incontinence. A case of a prolonged delayed hypersensitivity reaction following negative collagen skin testing after transurethral collagen injection is presented. Treatment of stress incontinence could not be initiated until symptoms decreased significantly after 1 year.