The disease is common about the age of puberty, and occurs in both sexes. Chronic derangement of the digestive apparatus is a frequent factor. Those of a light complexion are more liable to its development, while menstrual difficulties, chlorosis, scrofulosis, and general debility may all predispose to the disease. Medicinal substances, such as the iodides and bromides, and tar externally, are also prone to produce acne-form lesions. The retention of the secretion within the sebaceous gland is the first step in the formation of an acne lesion, and its presence—or it may be its decomposition—gives rise to inflammation, which usually involves the gland-structure and the surrounding tissue. Primarily, it is a folliculitis, the tissue immediately about the follicle subsequently becoming involved, constituting a perifolliculitis. As a result of this latter process, or from inflammation and changes within the gland without much surrounding inflammation, the destruction of the sebaceous follicles may ensue. The hair-follicles at times are also involved in the process. The degree of inflammation determines the character of the lesion; if mild in character, the simple papule or pustule results; if of a severe grade, the lesion of the indurated and hypertrophied forms follows.

Acne resembles at times the papular and pustular syphiloderms. In syphilis the distribution of the eruption, the history of the case, the color, the duration of the individual lesions, the tendency of the papules or pustules to group, and usually the presence of other evidence of the disease, will serve to distinguish it from acne. Tar acne may be recognized by the history, the black points at the follicular openings, and usually evidence of the presence of tar about the patient. Acne resulting from the ingestion of the bromides and iodides is almost always of an acute and markedly inflammatory type, the lesions being scattered over the general surface, and are usually larger and more virulent in character than those of acne vulgaris. From acne rosacea it may be known by the characters referred to in speaking of that disease.

TREATMENT.—Cases of acne vary considerably as to their course and curability. There is in almost every case a natural inclination toward disappearance of the eruption at the age of twenty or thirty. Although the lesions are at any age of the patient generally easily removable by treatment, relapses are the rule; but the older the patient the less probability is there of a recurrence. Even in young subjects, however, the cure may be permanent, depending upon the ability to discover and remove the cause. The disease requires both constitutional and local treatment. For the removal of the existing eruption local applications alone are usually sufficient, but the disposition to the development of new lesions in most cases yields only to appropriate internal treatment.

Each case of acne for its successful management demands careful investigation with a view of discovering the etiological factors. If these can be ascertained and removed, a successful result is assured. As already intimated, disorders of digestion play a most important part in the etiology of this disease, and in a large proportion of cases remedies appropriate to such conditions are required. The diet is to be strictly regulated: all indigestible articles of food, such as pork, salt meats, pastry, cheese, pickles, etc., should be interdicted. If constipation exists, laxatives are to be prescribed. As a rule, salines are more serviceable than vegetable preparations for plethoric individuals, while for others the latter, especially for long-continued administration, are to be preferred. A change from one to the other is often advisable. The dose should be sufficient to produce a free evacuation daily. An excellent tonic aperient mixture is the following:

Rx.Magnesii sulphatis,ounce iss;
Ferri sulphatis,gr. viij;
Acidi sulphurici diluti,fluidrachm ij;
Aquæ menthæ piperitæ,fluidounce iij drachm vi.

M.—S. A tablespoonful in a tumblerful of water a half hour before breakfast. The tonic effect of such a mixture is best obtained by prescribing one or two teaspoonfuls in a large wineglassful of water before each meal: as a rule, however, when thus given its laxative property is not so well marked. The mint-water may be replaced by a bitter infusion, such as quassia, but the mixture, unpalatable at the best, is not improved by such a substitution. In some cases the acid in the above mixture is contraindicated, and the following, also a valuable formula, may be prescribed:

Rx.Magnesii sulphatis,ounce iss;
Potassii bitart.,drachm iv;
Sulphuris præcip.,drachm ij;
Glycerinæ,fluidrachm ij;
Aquæ menthæ pip.,fluidounce iv.

M.—S. Tablespoonful in a tumblerful of water a half hour before breakfast. Hunyadi Janos water, in the dose of a large wineglassful thirty or forty minutes before the morning meal, is a useful saline, and is not especially disagreeable. Friedrichshall water is an efficient laxative and cathartic, but has a nauseous taste and odor. The ordinary mixture of rhubarb and soda is of value, not only for its laxative effect, but also for its antacid property where such is indicated. The following formula, containing cascara sagrada, is of service:

Rx.Ext. cascaræ sagradæ fl.,fluidrachm iv;
Acidi muriatici diluti,fluidrachm ij;
Tincturæ gentianæ comp.,fluidounce iij drachm ij.

M.—S. Teaspoonful in a large wineglassful of water before meals. At times this proportion of cascara sagrada is too large, and, on the other hand, in some cases it must be increased. A laxative pill, as the following, containing aloin, belladonna, and strychnia, may be given: