DEAR DR. GOTT: In a recent column in my local newspaper, you stated that liquid nitrogen could be purchased over-the-counter without a prescription. I have asked two pharmacists, and they said “no way.” Can it really be purchased somewhere OTC?

DEAR READERS: I apologize for the confusion. Liquid nitrogen is NOT available over-the-counter. Instead, the product that removes warts in a similar process uses dimethyl ether (DME). It only cools to about -59 C, whereas liquid nitrogen reaches approximately -195 C. Both can be dangerous and will cause serious injury if used improperly.

DEAR READER: Since my last column about plantar warts, I have received many letters about various treatments. Many of the readers claim that over-the-counter and physician treatments offered limited success, with the warts either returning or never completely disappearing. Many also complained of the pain associated with these treatments, which is why they turned to alternative and home remedies.

By far the most common remedy I received was iodine. The wart is first pumiced to remove the layers of dead skin and then the iodine is applied.

One reader suggested Cassia bark oil applied once a day after removing the dead skin with a razor. She warned that it should be applied only to the wart because it can damage normal skin. She also recommended tea tree oil for common warts on the hands.

Another reader took one 500-milligram capsule of olive leaf extract three times a day and was wart-free in three months.

Another person reported success treating her boyfriend’s plantar warts with a cotton ball soaked in apple cider vinegar applied to the wart and secured with duct tape each night. After a few weeks the warts were gone.

A physician wrote in suggesting soaking the foot in hot water and gradually increasing the water temperature until the skin turns cherry red. He says that two or three treatments are usually successful in eradicating the virus, thus causing the wart to disappear.

A final reader, attempting to avoid surgery to remove her son’s wart, was advised by a friend to use an herbal product known as Wart Wonder.

I cannot recommend or condemn any of these approaches because I have no experience with them. Please let me know if you and your daughter try any of these options and what your results are.

DEAR READER: Unfortunately, this situation is becoming more and more common. As you saw in my last column and in the above letter, many readers are frequently dissatisfied with the care they get from a doctor for common and plantar warts, not to mention how painful some of the procedures can be.

Remember, readers, that warts are caused by a virus and are commonly acquired by touching other warts (such as those on the hands), or by being barefoot in public showers or pool areas. Simple precautions such as hand sanitizers, wearing flips flops or water shoes, and using warm soap and water can help prevent outbreaks.

DEAR READER: Plantar warts are benign growths caused by the human papillomavirus (of which there are more than 100 types), which enters the body through cuts or breaks in the skin. These lesions present as small, hard bumps and are most commonly found on pressure points on the heels or balls of the feet.

The virus can spread from person to person simply through touching or scratching. Because each person’s immune system responds differently, some people may not be troubled by warts, while others, such as you, are extremely hampered by them.

Treatment is not necessary in all cases. When intervention is appropriate because of pain or lesions, a physician may choose cryotherapy (freezing). With this treatment, liquid nitrogen is applied directly to the warts, sometimes a blister forms, and the dead tissue sloughs off in a week or more. This therapy can cause pain, so for this reason it isn’t commonly used for young children. Other options include prescription cream, laser surgery, immunotherapy and cutting away of the warts.

On the home front, over-the-counter salicylic-acid solution or patches, duct tape and cryotherapy products are available. There are a number of brands available, but if the medication or patch is used, it should be a 40 percent salicylic-acid solution. Duct-tape therapy involves covering the wart for about a week, then soaking the area in warm water. This is followed by gently rubbing the lesion with a pumice stone or emery board. The process may require repeating once or twice before it is entirely gone. Cryotherapy products are also available without prescription; however, they don’t appear to be as effective as the freezing process done in a physician’s office.

There are preventive steps people can take to reduce their risk of getting plantar warts. Initially, keep your feet clean and dry, since warts thrive in a damp, warm environment. Wear flip-flops or another form of foot coverage when around public swimming pools or in locker rooms. Wash your hands thoroughly after touching any warts. Avoid direct contact with another person’s feet or hands if they have warts. If you use an emery board or pumice stone to file off lesions, do not use that same equipment on your fingernails.

To provide related information, I am sending you a copy of my Health Report “Compelling Home Remedies.” Other readers who would like a copy should send a self-addressed stamped No. 10 envelope and a $2 check or money order payable to Newsletter and mailed to Newsletter, P.O. Box 167, Wickliffe, OH 44092-0167. Be sure to mention the title or print an order form off my website at www.AskDrGottMD.com.