Ear piercings mark a special -- and sometimes painful -- step in many girls' lives.

But not all piercings are created equal when it comes to risk of infection, according to a study published in Wednesday's issue of the Journal of the American Medical Association.

Lead researcher Dr. William Keene, of the Oregon Department of Human Services in Portland, and several colleagues at the University of Washington found that for ear piercings, cartilage piercing is more likely to become infected than lobe piercing.

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"Cartilage piercing is not as safe as getting your ear lobe pierced," Keene said. "It is much more prone (to infection) because of the lack of blood to the area to get these kind of serious infections."

The Oregon health department investigated what caused at least seven people ages 10 to 19 to get a severe infection after getting their thin upper-ear cartilage pierced at a jewelry kiosk in 2000. They discovered the jewelry stand in a rural Oregon mall was using unsanitary and out-of-date equipment.

The source of the infection was a common germ called pseudomonas aeruginosa that was in a bottle of disinfectant. The bottle was supposed to be used only once, but the Oregon Department of Human Services says it was reused repeatedly to sterilize earrings.

The infection that developed can be very serious. It can be treated with antibiotics, but upper-ear cartilage is harder to treat than earlobes.

"The ear loses its ability to hold its shape, and so the ear kind of crinkles up and becomes quite unsightly. So it is a disfiguring infection," Keene said. "It doesn't affect your hearing, it doesn't affect long-term health, but cosmetically, it is quite unfortunate."

Keene warned while piercing is common, it is still an invasive procedure. To cut down on infection, he recommended that people look for places that have well-trained employees, updated equipment and a sanitary environment.

Study Abstract