The skin on the bottom of the feet is eight to 10 times thicker than elsewhere on the body. A callus is an abnormally thickened mass of skin which may or may not have a more hardened central area (not to be confused with a corn whose centre goes into the skin). They are often the result of friction which can be caused by wearing open-toed shoes or slip-ons with no support to hold the shoe on. A healthy callus forms as a natural barrier against damage to the underlying sensitive tissue. Women suffer from this type of foot problem more often than men do because they wear an unsuitable shoe, high heels, or pick a too-small fit.

Those who do a lot of walking or standing are more likely to develop calluses from the pressure. In more unusual cases, the callus may be caused by a fungus infection, eczema, psoriasis, etc. A doctor or podiatrist should be consulted. Special shoe fittings may be necessary because some feet are more difficult to fit than others. It is not uncommon, for example, for the foot length to measure one size from the heel to the arch and another size from the arch to the toes. The heel may also be proportionately smaller or larger than the rest of the foot.

Pumice stones and lotions are helpful in controlling the dry skin or very small calluses but, as you have discovered, are almost ineffective with the very thick or fissured ones you describe. We suggest that you first have a professional pedicure. An esthetician or a podiatrist can treat the calluses, the choice depends upon the extent of treatment you want. With an esthetician, the pedicure takes one hour or more. The feet are first soaked in warm water and the calluses are actually shaved off. This does not hurt as the calluses are composed of dead skin. The skin is then smoothed down with a pumice or a sloughing cream. As part of the pedicure, the nails are trimmed and lacquered if desired and a foot massage with a moisturizing cream is included. With a podiatrist, the calluses are shaved down and any corns can be treated as well.

Having an initial pedicure will make it easier for you to take care of your feet at home. Soak in warm water, then smooth down the skin with a pumice or a special abrasive pad. Then massage in a foot cream (preferable over a lotion) and pay particular attention to problem areas. Consistency of treatment is necessary. The pumicing can be done every second night, depending on the severity of the problem, and the cream should be applied every night.

I have a problem which I would like to work on during the winter. The skin on my knees is much darker than the rest of my legs. They actually look dirty. I use a pumice on them twice a week but notice little improvement. Have you any suggestions?

The skin in areas that are subject to continuous friction, such as on the knees and elbows, can become discolored with the build- up of dry, keratinized skin (keratin is a hard protein found in the skin cells). You could try bleaching the skin with some diluted lemon juice. First remove some of the dead skin cells by brushing with a loofah using circular motions. Dilute the lemon juice and apply it to the skin leaving it to act for five minutes. Rinse off well then apply a good moisturizing body cream as lemon can be dehydrating. You should see the results within a couple of weeks. If not, you may wish to ask your doctor to refer you to a dermatologist for further treatment.