A system of practical medicine. By American authors. Vol. 4

by Unknown

Prurigo is a chronic inflammatory disease, characterized by discrete pinhead- to small pea-sized, solid, firmly-seated papules, slightly raised, of a pale-red color, accompanied by general thickening of the skin and itching. The disease manifests itself by the development of small firm elevations, which at first are scarcely perceptible; but they may be distinctly felt by passing the hand over the surface. Later, they may be seen as slightly-raised papules, varying in size from a milletseed to a small pea, of the same color as the surrounding skin or of a pinkish hue, and to the touch are found to be well-defined inflammatory deposits. The lesions are discrete, may be present in great numbers and in close proximity, and show no tendency to group, being irregularly distributed. There is rarely distinct scale-formation, but the papules are usually covered with roughened, dry epidermis, and are frequently perforated with hairs.

Itching, usually intense, is a constant symptom, giving rise to scratching, and as a consequence many of the lesions are covered with blood-crusts and the skin is markedly excoriated. In course of time, either as a symptom of the disease or as a result of the scratching and consequent hyperæmia, or more probably resulting from both, the skin becomes thickened and the surface harsh or rough. The extensor surfaces of the legs, especially the tibial regions, and later the forearms and arms, and in marked cases the trunk, are the regions usually invaded. The palms and soles escape, and only in rare cases is the head involved. As a result of strong local remedies or scratching, or of both, a simple dermatitis or an eczema may develop as a complication. In consequence also of the cutaneous irritation the lymphatic glands, especially the inguinal, may become engorged—prurigo buboes (Hebra).

The causes of the disease are obscure. It is common in Austria, and is occasionally met with in France and England, but it is almost unknown in the United States. It is met with, as Hebra states, almost exclusively in poor subjects and those ill nourished in childhood, and so most often in foundlings and beggars' children. The disease is not hereditary. It usually develops, however, in early childhood, and is worse in winter than in summer. Anatomically, the lesions differ but slightly from those of papular eczema. The papillæ and rete show a moderate amount of cell and serous infiltration. Later, as a result of the chronic inflammation, thickening, increased cell-infiltration, atrophied sweat and sebaceous glands, and pigmentation are observed. The process, according to various authorities, begins in the papillary layer.

Prurigo has been, and is still, erroneously confounded with pruritus and pediculosis, diseases which have nothing in common with that affection except the itching and resulting excoriations—symptoms, as is well known, common to many diseases. In pruritus there is no structural change in the skin except that produced by scratching, a point of difference that is diagnostic. The thickening of the skin and the harsh, rough surface encountered in prurigo are absent in pruritus. The latter disease is usually one of middle or old age; prurigo, on the other hand, dates from childhood. In pediculosis the lesions, punctate or papular in form, are consequent upon the wounds of the pediculus, and are most numerous about the trunk, especially the shoulders and hips. Between simple eczema and prurigo the diagnosis is not difficult. It is to be remembered, however, that eczema may exist as a complication, in which case, after its disappearance, the characteristics of prurigo become evident.

Severe cases are said to be incurable, according to Hebra and others, but in the milder forms of the disease a cure may be effected. Good food, hygiene, and tonic remedies, and systematic local treatment similar to that generally employed in chronic eczema, are the measures indicated. Naphthol, in the form of a 5 per cent. ointment for adults and a ½ per cent. ointment for children, has been found by Kaposi to be of value.

Acne.

Acne, or acne vulgaris, is an inflammatory, usually chronic, disease of the sebaceous glands, characterized by papules, tubercles or pustules, or a combination of these lesions, occurring for the most part about the face. There are several so-called varieties of acne, although examples of all these forms may be seen usually in an individual case, and instances in which all the lesions are of the same type or character are practically not encountered. Other disorders of the sebaceous glands, as comedo and seborrhoea, are often seen associated with this affection. In fact, hypersecretion or retention of the sebaceous matter is the exciting cause of the inflammation.

If the retained sebaceous mass causes a moderate degree of hyperæmia or inflammation, a slight elevation with a central whitish or blackish point results, constituting the lesion of acne punctata. If the inflammation is of a higher grade, the elevation is more marked, reddened, and papular, the lesion being known as acne papulosa. If the process is still more active, the central portion of the papule suppurates and acne pustulosa results. The surrounding inflammation of this form is often of a violent type, and the lesion may be situated upon a hard and inflamed base, and then is designated acne indurata. In some cases of acne the disappearing lesions leave more or less atrophy about the gland-ducts in the form of pit-like depressions—acne atrophica. On the other hand, at times there results connective-tissue hypertrophy about the glands—acne hypertrophica. In strumous, cachectic individuals the lesions, which are usually pustular in type, or at times furuncular, almost of the nature of dermic abscesses, may be more general in distribution, and are, moreover, usually of a more sluggish character, constituting the so-called acne cachecticorum. The efflorescence which follows the prolonged ingestion of the iodides and bromides is usually of a more inflammatory type, the glands and follicles being sometimes seriously and irreparably involved. This form of acne, as well as that resulting from the external action of tar, characterized by the formation of all kinds of lesions with a minute central blackish deposit of tar and more or less inflammation of the surrounding skin, constitutes acne artificialis.

The most common form of acne is that in which the pustule predominates. The lesions, in all the varieties, are usually confined to the face, the forehead, cheeks, and chin being favorite localities; not infrequently, however, the eruption also involves the shoulders and upper part of the back. They are irregularly distributed and tend to appear in crops. Sometimes the face and shoulders are spared, and the lesions, being confined to the back, extend as far down as the lumbar region or even to the thighs. In these cases the lesions are usually of a papulo-pustular character and are sluggish in their evolution. As a rule, an acne papule or pustule runs an acute course, disappearing in the course of one or two weeks, and a new lesion appearing at another point to supply its place. The disease is essentially chronic, in the sense that the parts are never or seldom free, new lesions forming and old ones disappearing from time to time, in some cases indefinitely. As a rule, there are no subjective symptoms, but in some markedly inflammatory cases the lesions are painful; in other exceptional instances there is slight itching.