Prolonged urinary retention after collagen periurethral injections: a sequela of humoral immunity

Approximately 3% of candidates for collagen periurethral injections are ineligible because of an immediate hypersensitivity reaction to skin testing. After a negative skin test, physicians believe patients should be free of any adverse clinical events from hypersensitivity reactions. We present a patient who developed prolonged urinary retention from a delayed hypersensitivity reaction after negative skin testing.

After a negative skin test, a 51-year-old woman underwent collagen periurethral injections for recurrent genuine stress incontinence associated with a fixed bladder neck. After reporting complete resolution of symptoms, she developed complete urinary retention associated with a delayed hypersensitivity reaction at both the skin test and injection sites. Her retention resolved after a year of intermittent catheterization and antibiotics for persistent urinary tract infection.

Delayed hypersensitivity reactions may be associated with an adverse clinical event in up to 2.5% of patients despite a negative skin test. After skin testing, physicians should counsel their patients accordingly.