Can people ever lose their fingerprints?
Science writer Katherine Harmon interviewed experts to hand over the answer:
Fingerprints can indeed be removed, both intentionally and unintentionally. The May 2009 issue of the Annals of Oncology reported (online) a striking example of the latter case: a 62-year-old man from Singapore was detained while traveling to the U.S. because a routine fingerprint scan showed that he actually had none.
The man, identified only as Mr. S, had been taking the chemotherapy drug capecitabine (brand name Xeloda) to keep head and neck cancer in check. The medication gave him a moderate case of hand-foot syndrome (also called chemotherapy-induced acral erythema), which can cause swelling, pain and peeling on the palms and soles of the feet—and, apparently, loss of fingerprints. Mr. S, who was freed when officials decided he was not a security risk, says he had not noticed that his fingerprints had vanished before he set out on his trip. After the incident, Mr. S's physician, who authored the paper, found informal online mentions of other chemo patients complaining of lost fingerprints.
Edward P. Richards, director of the Program in Law, Science and Public Health at Louisiana State University, says that other diseases, rashes and the like can have the same effect. “Just a good case of poison ivy would do it.” But he observes that “left alone, your skin replaces at a fairly good rate, so unless you've done permanent damage to the tissue, it will regenerate.”
Kasey Wertheim, who is president of Complete Consultants Worldwide and has done forensic and biometric work for the U.S. Department of Defense and Lockheed Martin, says that the people who most often lose their fingerprints seem to be bricklayers, who wear down print ridges handling rough, heavy materials, as well as “people who work with lime [calcium oxide], because it's really basic and dissolves the layers of the skin.” Secretaries may also have their prints obliterated, he adds, “because they deal with paper all day. The constant handling of paper tends to wear down the ridge detail.”
“Also,” Wertheim, notes, “the elasticity of skin decreases with age, so a lot of senior citizens have prints that are difficult to capture. The ridges get thicker; the height between the top of the ridge and the bottom of the furrow gets narrow, so there's less prominence.” Burning—with heat or chemicals—can blot out fingerprints as well, but then the resulting scars can become a unique identifier.
Wertheim says that many cases of intentional fingerprint mutilation have been documented. Usually in these instances, people damage the layer of skin that forms the “template” for the fingerprint and the epidermis at the surface.
The first case of documented fingerprint mutilation, he points out, was back in 1934, by Theodore “Handsome Jack” Klutas, who was head of a gang known as the College Kidnappers. “When the police finally caught up with him, Klutas went for his gun, and the police returned fire, killing him,” Wertheim recounts. “When they compared his postmortem fingerprints, police found that each of his prints had been cut by a knife, resulting in semicircular scars around each fingerprint. Although he was glorified in the media, it was an amateur job; the procedure left more than enough ridge detail to identify him.”