(Callosity; Callus; Tyloma; Tylosis)
Definition. – Hard, horny, thickened patches occurring usually on the hands or feet, due to intermittent friction or pressure.
Symptoms. – This condition is usually found on the palms, soles, fingers or toes. The lesions are grayish, yellowish or black in color, slightly elevated, tough or horny in consistency and more or less circumscribed or round. Inflammation is usually absent although pain may be experienced upon the soles, particularly if the shoe soles be thin.
Etiology and Pathology. – Friction or pressure, usually intermittent, from tight or badly fitting shoes or from the use of some hard implement, produces callus; when constant it usually results in atrophy or ulceration. Ordinary callosities which are the result of labor may last indefinitely without discomfort or injury. Hypertrophy of the horny layer of the epidermis is the constant pathological finding.
Treatment of callus is purely mechanical, if necessary at all, and consisting in thinning with a file, rubbing down with pumice stone, or paring with a knife after previously softening in hot water. A 10 to 25 per cent. salicylic acid plaster may be applied for a few days, after which the horny substance may be peeled off. Nitrate of silver in stick form can be applied after the hard skin has been shaved. Repeated freezings with solidified carbon dioxide, using deep pressure for one minute, will remove these formations. The removal of the cause, if possible, is the best preventive. Antim crud. has a marked effect upon the tendency to callus formation.