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Management of zipper injuries

Joan Bothner, MD
Section Editor
Anne M Stack, MD
Deputy Editor
James F Wiley, II, MD, MPH


Zipper entrapment of the penis is an uncommon injury in prepubertal boys. These injuries typically involve the foreskin or redundant penile skin and may occur during the zipping or unzipping process [1]. Localized edema, superficial tissue abrasions, bruising, and pain are the most common complications of zipper injuries; skin loss or necrosis, is unusual.


Zipper entrapment injuries occur infrequently. In one case series from a pediatric emergency department (ED), one zipper entrapment injury occurred per 4000 new ED attendees [2]. In this series of 30 boys between the ages of 2 and 12 years of age, 60 percent of the affected boys were wearing underwear at the time of the injury. Most of the injuries were self-inflicted (84 percent) and occurred as the zipper was being zipped up as opposed to down (92 percent).


In most instances, the uncircumcised foreskin is entrapped in the zipper (figure 1) [3]. Occasionally, redundant tissue on the ventral side of the circumcised penis is involved.

A zipper is composed of interlocking dentitions that are aligned by a fastener consisting of an inner faceplate, outer faceplate and median bar (picture 1) [3]. The fastener and cloth hold the zipped dentitions together. If either the cloth or fastener is disrupted, the zipped dentitions fall apart.


The clinician should attempt removal of entrapped penile tissue as soon as possible after the zipper injury. With time, swelling and edema of the entrapped tissue makes successful management more difficult. Penile entrapment that involves the urethra or false attempts using the procedures described below, warrants prompt referral to or consultation with a urologist.

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Literature review current through: Dec 2017. | This topic last updated: Nov 30, 2016.
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  1. Yip A, Ng SK, Wong WC, et al. Injury to the prepuce. Br J Urol 1989; 63:535.
  2. Wyatt JP, Scobie WG. The management of penile zip entrapment in children. Injury 1994; 25:59.
  3. Fein JA, Zderic SA. Management of zipper injuries. In: Textbook of Pediatric Emergency Procedures, 2nd ed, King C, Henretig FM (Eds), Lippincott, Williams & Wilkins, Philadelphia, PA, USA 2008. p.908.
  4. Taddio A, Stevens B, Craig K, et al. Efficacy and safety of lidocaine-prilocaine cream for pain during circumcision. N Engl J Med 1997; 336:1197.
  5. Lander J, Brady-Fryer B, Metcalfe JB, et al. Comparison of ring block, dorsal penile nerve block, and topical anesthesia for neonatal circumcision: a randomized controlled trial. JAMA 1997; 278:2157.
  6. Lewis LS, Stephan M. Local and Regional Anesthesia. In: Textbook of Pediatric Emergency Procedures, Henretig FM, King C (Eds), Williams & Wilkins, Baltimore 1997.
  7. Oosterlinck W. Unbloody management of penile zipper injury. Eur Urol 1981; 7:365.
  8. Kanegaye JT, Schonfeld N. Penile zipper entrapment: a simple and less threatening approach using mineral oil. Pediatr Emerg Care 1993; 9:90.
  9. Flowerdew R, Fishman IJ, Churchill BM. Management of penile zipper injury. J Urol 1977; 117:671.
  10. Nolan JF, Stillwell TJ, Sands JP Jr. Acute management of the zipper-entrapped penis. J Emerg Med 1990; 8:305.
  11. Strait RT. A novel method for removal of penile zipper entrapment. Pediatr Emerg Care 1999; 15:412.
  12. Raveenthiran V. Releasing of zipper-entrapped foreskin: a novel nonsurgical technique. Pediatr Emerg Care 2007; 23:463.