Ulcers

Ulcers are solutions of continuity of three dimensions - namely, length, breadth, and depth. Their borders may be sharp cut and perpendicular to the skin, or may be sloping or overhanging, features which often afford a valuable clew to the origin of the lesion.

The principal diseases in which ulcers are found, and their chief features are:

In addition to the above there are certain other lesions, some of which are secondary, while others are peculiar to certain special diseases, and will be described in connection with them.

With the foregoing list of diseases and lesions, and with their chief peculiarities visible at a glance, there should be but little difficulty in working out an analytical diagnosis in the great majority of cases of cutaneous disease. We would, however, advise the student to pursue the following course: First, determine the predominant lesion, then turn to the list of diseases which are characterized by that lesion, and see how closely the descriptions there given agree with the appearances presented; and, when a choice is made, carefully read the description of the disease itself as found in later pages of the book. Should the disease in question present more than one lesion, examine the lists of diseases under each lesion, and proceed as before. Several years' experience in studying dermatology has satisfied the writer that the pursuit of the method here laid down will enable the student to become a prompt and correct diagnostician in a surprisingly short time. He will, of course, meet with cases in which he will not succeed, but he should remember that cases not infrequently occur which puzzle even the most expert.