SAN DIEGO — Zippers are the most frequent cause of penile trauma among adults in the United States, with an estimated 2000 cases each year, according to a presentation here at the American Urological Association 2016 Annual Meeting.

For children, toilet seats are the leading cause, but zippers are "a close second," Lawrence Wyner, MD, a urologist at Joan C. Edwards School of Medicine at Marshall University in Huntington, West Virginia, reports in his meeting abstract.

The phenomenon even has its own acronym — ZIRPI, for zipper-related penile injury — and was first described in JAMA in 1936 (1936;107:809).

"Many urologists have seen at least one ZIRPI during their careers," Dr Wyner writes.

Risk factors for ZIRPI include being younger than 18 years and having an uncircumcised or insufficiently circumcised penis. "The contribution of 'going commando' (i.e., sans underwear) remains controversial," he writes.

The contribution of 'going commando' remains controversial.

Dr Wyner's presentation — entitled A Century of Urological Mayhem From Zippers — was part of the History of Urology session.

His efforts did not go unnoticed. "New favorite medical acronym, ZIRPI. See I learned something at #AUA16," tweeted Benjamin Davies, MD, a urologist from the University of Pittsburgh in Pennsylvania (@daviesbj).

The legal world views a penis caught in a zipper as being the fault of the male. "Consumer complaints involving zippers are almost exclusively related to either choking or asphyxiation hazards, and potential litigation involving ZIRPI is generally regarded as frivolous," says Dr Wyner.

A "Separable Fastener"

Although zippers are commonplace today, their uptake was slow.

Nearly 100 years ago, Swedish–American engineer Gideon Sundback obtained a patent in the United States for his improvements to the clasp locker, which was known as an unreliable boot-lacing mechanism. The invention went unnoticed until the B.F. Goodrich company placed the new device, which was called a "separable fastener," on rubber galoshes in 1923. The device was given the "catchy onomatopoetic name" of zipper at that time, says Dr Wyner.

For the next decade, zippers were reserved for footwear and tobacco pouches. Aldous Huxley, in his famed 1923 novel Brave New World, even satirized zippers.

Things dramatically changed in the mid-1930s, when British royalty began wearing zippered trousers and the fashion took hold.

Dr Wyner reports that Sundback and his zipper company, eventually known as the Hookless Fastener Company, had "some reservations about possible genital mishaps from its creation."

But the device has been time- and market-tested. As Dr Wyner points out, even Velcro, introduced in the 1950s, has not derailed the zipper.

Dr Wyner has have disclosed no relevant financial relationships.

American Urological Association (AUA) 2016 Annual Meeting: Abstract FRII-15. Presented May 8, 2016.

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