PRURIGO is a disease of the skin characterised by an eruption of small pimples and a most intense burning sensation of itching. The pimples are usually but slightly if at all red, and the skin between them has its natural colour. They are generally seated about the shoulders, back, and neck, but often also on the limbs, and in severe cases even on the face Andover a great part of the body. Their course is always very slow, and they are not infectious.
There are three principal varieties of Prurigo, namely, P. mills, P. form leans, and P. senilis ; and besides these, some others are distin guished by the names of the parts which are in each exclusively or chiefly affected.
The Prurigo mills is the mildest form of the disease. The pimples are very small, and so pale that they can scarcely be disccrued, till, by the scratching, which is almost unavoidably resorted to in order to relieve the intolerable itching, their tops are torn off, and become covered by little black scabs of dried blood.
In P. forrnicans all the symptoms of the disease are more severe, and the itching by which they are accompanied is united with a pain ful burning sensation in the skin, as if, patients say, hot needles were constantly piercing it. Both this and the preceding form of Prurigo may disappear with a alight desquamation in a few weeks, but more commonly a succession of eruptions follow one another, and the disease is prolonged for months or even years. Both of them occur in of all ranks and ages, but they are most common in the young and in the old, and among those who enjoy fewest of the comforts of life. They are not attended by any important constitutional disorder.
Prurigo senilis, which is by far the worst form of the disease, occurs almost exclusively in enfeebled children and old people. It usually
lasts four years, producing all the time almost intolerable suffering by the intense itching that attends it. and which scarcely admits of relief by any known means. The pimples are usually very numerous, and often hard and prominent ; the skin between them is also often thickened and indurated, other eruptions break out upon it, and if cleanliness be not carefully observed, it becomes infested with swarms of lice.
The treatment of the first two forms of Prurigo must consist of a mild antiphlogistic regimen, tepid baths, and the use of alkalies both externally and Internally. Stimulants of all kinds greatly increase the pain and itching, but they may sometimes be relieved by the application of ointments or lotions containing small quantities of opium, or prussic acid, or cyanuret of potassium. In the Prurigo senilis the regimen must be more nutritious, and tonic medicines are useful; but in this form, as well as in the others, stimulants must be avoided. if the skin is infested with pediculi, the most effectual mode of destroying them is fumigation with the vapour of cinnabar. In this form also sulphur-baths are among the few means that will produce any relief. The alkaline lotions, which may be used in all cases, may he composed of one or two drachms of carbonate of potash to the pint of water, or of from one to three drachms of sulphuret of potash to the same quantity of water, the strength being determined by the irritability of the skin, and being always made less than sufficient to excite any heat or redness in it.