Anthrax carbuncle of forearm. (Lexer.)
CHRONIC INFECTIONS OF THE SKIN.
Tuberculosis.
—Most of the skin lesions formerly described as scrofulous are now known to be expressions of tuberculosis. So, also, are some of the papillomatous growths and the chronic ulcers, which do not assume distinctive form.
Lupus vulgaris is perhaps the most common of these cutaneous lesions, especially in certain parts of the world. It is seen more often among the young than the old. The lesions begin with a papule, which becomes the well-known lupus, smaller nodules coalescing and forming eventually a brownish-red patch, whose borders are somewhat elevated and scaly. This lesion usually goes on to ulceration, particularly in those parts of the body where it is kept moist or frequently irritated. It is in these lesions that a healing or cicatrizing tendency is seen at one point and progressive ulceration in another. Ulceration does not always occur, but the papule just described sometimes undergoes spontaneous absorption, the tissue atrophying, losing its peculiar skin functions, and the scar being depressed and scaly.
Lupus vulgaris is to be distinguished from lupus exedens, referred to under [Epithelioma]. It is often mistaken for the latter, and a differential diagnostic table has already been given. (See [p. 293].)
Verruca necrogenica, as it used to be called, is now known as verrucose tuberculosis. It consists of cutaneous warts, surrounded by an erythematous zone or patch, which tend to break down, and covered with scabs, intermixed with pustules. The lesion rarely proceeds to complete ulceration. It occurs especially upon the hands and exposed parts of those who handle cadavers or carcasses. The lesion is usually slow and sometimes disappears spontaneously.
On or about the mucocutaneous borders of individuals suffering from tuberculosis there appear small ulcers, secreting a thin, puruloid material. These are seen especially about the nose, the mouth, the anus, and the vulva. These lesions should be regarded as local infections from a constitutional source. They are often sensitive, show little tendency to heal, and are sources of danger to others. They should receive radical treatment.
Under the term scrofuloderm are included a variety of subcutaneous tuberculous nodules which spread and involve the skin. They begin in the superficial lymph nodes. The overlying skin becomes bluish and gives way, while an ulcer remains which discharges more or less puruloid material. The edges of these ulcers are frequently undermined for a considerable distance. These are ordinarily chronic lesions, which sometimes undergo a spontaneous recovery, leaving disfiguring and discolored scars, usually irregular and more or less striped or banded.
Some of the scrofuloderms are included under the erythema induratum of Bazin, lesions which appear mostly on the calves of the legs of young women, consisting of deep-seated nodules, which break down into deep ulcers, having elevated and overhanging edges. Again, there is the so-called lichen scrofulosorum, i. e., a papular eruption seen in the young, especially those who show other evidences of tuberculosis. It consists of rounded groups of papules, usually on the sides of the trunk, at first bright in color, new papules appearing as the old ones fade. In addition there is the pustular scrofuloderm, which crusts over, heals, and leaves small cicatrices.