Definition And Description

Prurigo is a name that has been used in a variety of significations, chiefly to denote a condition of itching or pruritus, arising from a number of causes - in other words, as the name of a symptom rather than of a disease. We here confine it, however, in accordance with present dermatological usage, to a special disease first clearly defined by Hebra. The disease is quite rare in this country, and the following description is taken from the author just named:

The affection in all cases commences by the appearance of small sub-epidermic papules, more easily appreciable by touch than by sight, since they rise but little above the level of the skin, and do not differ from it in color. They are always isolated. They give rise to a good deal of irritation, and in consequence of scratching become a little more elevated and of a redder color. Repeated scratching destroys their epidermic covering and permits the discharge of a transparent or yellowish serum, or if the papillae be wounded the escape of a droplet of blood which forms a minute blackish crust upon the summit of the papule. As the papules exist in considerable number, this process, repeated in them all, produces the aspect to which the name of ordinary prurigo may be given.

When, however, the affection has lasted some time, new phenomena are added to those already mentioned. Pigmentation of skin, gradually increasing, and corresponding to the location of the scratch-marks, becomes a prominent feature. The natural lines and furrows of the skin become more widely separated, and more distinct than in the normal condition, specially noticeable about the backs of the hands and wrists. The downy hairs are torn out by scratching, or broken off and disorganized, and the skin itself is harder and thicker than in health.

In severer cases all of these symptoms become exaggerated. The papules are larger, the itching more intense, the excoriations more se-vere, and the number of blackish blood-crusts increased. In addition we notice a more general brownish pigmentation, and a detachment of the outer layers of the epidermis under the form of a whitish branny desquamation. In some cases a vesicular or pustular eczema may be developed, masking, to a certain extent, the peculiar features of the primary affection.

The disease is exceedingly chronic, and in Hebra's experience persists throughout the whole lifetime of the patient. It does not, however, appear to exert any noxious influence on the general health, or to shorten the life of the unhappy sufferer.

Diagnosis

Many of the features of prurigo are common to it, and the various forms of pruritus, as, for instance, the itching, the scratch-marks, and the pigmentation of the surface. On the other hand, the peculiar papules are pathognomonic, and are sufficient, in connection with the other symptoms, to enable the nature of the affection to be promptly recognized.

Prognosis

Although recently some cures of Prurigo have been announced, the prognosis, on the whole, is exceedingly bad.

Treatment

Hebra found the disease incurable; he nevertheless was able to obtain great amelioration of the condition of the skin by judicious and persistent treatment. Internal medication was useless, but local measures, calculated to soften and hasten the desquamation of the external layers of the skin, were of decided service. Baths of all sorts, warm, cold, or vapor, were of the first importance. In addition, thorough applications of green soap were frequently employed. Sulphur, whether used in baths, ointments, or soap, was found very useful, as was also Vlemingkx's Solution. The various preparations of tar were found to possess a marked influence in diminishing the irritation.

Quite recently the internal administration of Jaborandi has been found very beneficial at the hands of Simon.

The following drugs may also be considered: Acidum Carbolicum, 6; Acid. Hydrocyanicum, 8; Acid. Pyrogallicum, 10; Acid. Sulphuric., 11; Colchicum, 46; Creosotum, 48; Ergota, 52; Hydrarg. Chlor. Cor-ros., 64; Hydrarg. Nitras, 66; Laurocerasus, 73; Ol. Morrhuoe, 78; Petroleum, 83; Ribes rubrum, 101.

In reference to the foregoing it may be stated, that although recommended for "prurigo," other pruriginous affections, and not the disease here described, were doubtless, in many instances, included.