Is using over-the-counter wart treatments safe?

You can't damage yourself with these OTC treatments. If you get salicylic acid on normal skin, it can cause burning or redness but rarely infection or scarring. All you have to do is stop using it on irritated areas and the skin returns to normal. Still, it's probably better not to use salicylic acid on sensitive areas like the face or groin, where it's likely to make nearby skin raw and uncomfortable.

It generally is recommended that salicylic acid not be used in people with diabetes or in areas where there is poor circulation (because of concern about how normally the skin can heal; however, in practice, salicylic acid is withheld only when there are clear signs of ongoing inflammation of the skin).

Likewise, nonprescription freezing products are also reasonably safe but must be used carefully and only according to package instructions because they work by destroying living tissue.

Are wart treatments effective?

Above all, wart treatments require patience. Since there are so many different types of treatments, how effective they are is another matter. Warts can appear and disappear without an identifiable cause and often disappear on their own without treatment. Some warts sprout daughter warts near the main wart and others don't. Warts are generally painless unless they are present in areas prone to pressure or friction like the palms and soles. Certain warts, even of the same type, respond to treatment, while others (even on the same person at the same time) don't. All treatment methods often require many sessions over weeks, months, or longer.

Here is a practical approach to the treatment of warts:

a. If you can ignore your warts, do so. Eventually, they'll go away (although eventually can mean a long time -- even months or years).

b. If you have an uncomplicated case (a single wart on the face or one or a few on the hands), see a doctor for a quick freeze or electrical destruction. These methods are simple, although somewhat painful, and generally nonscarring.

c. If you have a difficult case, you can start by treating the warts for a few weeks on your own. Here are some examples:

Plantar warts: 

Warts on the bottom of the foot feel deep, but they are still within the superficial layer of the skin. Tender plantar warts can be rendered painless by paring the wart thinner without causing bleeding. Salicylic-acid drops and plasters help remove the thick overlying callus and make the wart feel less like a marble in your shoe. Nonprescription aerosol freezing may be used as well.

Common hand warts: 

These are typically unattractive although not painful. Salicylic acid can make them smaller and go away, in some cases, as can nonprescription freezing.

If you have an all-but-impossible case, don't try too hard. You don't want to make the treatment worse than the disease. Here are some examples:

Warts under and around the nails: 

These are extremely resistant to treatment. One or two tries by the doctor are worth a shot, but if they fail, putting acid on them yourself just makes them look rough and unattractive.

"Mosaic" warts: 

Tiny, so-called "seed warts" can proliferate by the dozens or hundreds all over the sole of the foot. They don't usually hurt, and they rarely respond to any sort of treatment, although in this case, too, one or two tries at treatment may be in order.

Flat warts: 

These are small, flat, flesh-colored pimples and may be numerous on one part of the body (for example on the face, arms, or groin). Getting rid of them by a light application of salicylic acid or other method is easy enough, but they have a tendency to recur.

Reference:

http://www.medicinenet.com/