Wart removal seems so simple a medical treatment that it would be hard to mess it up. Until you start a fire.
The Food and Drug Administration says that it has received reports of 14 people being burned or starting fires while using wart-freezing devices since 2009.
Cryogenic wart removers contain a mixture liquid dimethyl ether and propane, which is highly flammable and doesn't require very high temperatures to catch fire.
Injuries have included singed hair, blisters and burns, according to the FDA.
Three of the fires were caused by candles; the other sources of heat were unidentified. But everyday household items like curling irons could be hot enough to ignite vapors, according to the FDA.
Labels on the cryotherapy wart removers warn that the gas they emit is flammable, but that risk may not be immediately obvious to the casual user. Using them as directed away from hot objects shouldn't pose a threat, Richard said.
But some people use wart-freezing devices too enthusiastically, which can damage skin even if there's no fire, dermatologists say. Overuse can severely damage the surrounding skin, leading to redness, blisters or the death of tissue.
Dermatologists don't really know why freezing a wart can make it go away or how it affects the human papillomavirus, which causes warts. "[It's] possibly by simple destruction of infected skin or by triggering the immune system of the patient, or both," Richard said.
There are other wart-removal choices that don't pose a risk of fire. They include salicylic acid that gradually softens the skin around the wart, immunotherapy that can trigger the body's own defense system, and a do-it-yourself duct-tape method that peels away layers of the wart.
And then there's doing nothing; warts do tend to go away on its own.
But warts that return need a doctor's attention, according to Dr. Anthony Gaspari, a dermatology professor at the University of Maryland Medical Center. Doctors have other tools, including laser surgery and liquid nitrogen, which freezes the wart at a chilly -320 degrees Fahrenheit.
There may not be a "magical cure" for warts, as Gaspari puts it, but his advice is to keep at it – with caution, of course.