Psoriasis

(Lwgeos, from, Jweow, to itch.) The disease to which Dr. Will an gives. this title is characterized by a rough and scaly state of the cuticle, sometimes continuous, sometimes in separate patches, of various sizes, but of an irregular figure, and for the most part. accompanied with rhagades or fi ures of the skin, From the lepra it may be distinguished, not only by the distribution of the patches, but also by its ce ation and recurrence at certain seasons of the year, and by the disorder of the constitution with which it is usually attended. Dr. Will an gives the following varieties: Psoriasis guttata,—diflusa,—gyrata,—palmar i a,— Jabialis,—in fan til is,—inveterata, Psoriasis guttata, This complaint appears in small, distinct, bat irregular patches of laminated scales, with little or no inflammation round them. The patches very seldom extend to the size of a sixpence. They have neither an elevated border, nor the oval or circular form by which all the varieties of lepra are distinguished; but their circumference is sometimes angular, and sometimes goes into small serpentine proce es, The scale formed upon each of them is thin, and may be easil detached, leaving a red, shining base. ‘The patches are often distributed over the greatest part of the body, but more particularly on the back part of the neck, the breast, arms, loins, thighs, and legs. ‘They appear also upon the face, which rarely happens in lepra. In that situation they are red and more rough than the adjoining cuticle, but not covered with scales. The psoriasis guttata often appears on children in a sudden eruption, attended with a slight disorder of the constitution, and spreads over the body within two or three days. In adults it commences with a few scaly patches on the extremities, proceeds very gradually, and has a longer duration than in children. Its first occurrence is usually in the spring season, after violent pains in the head, stomach, and limbs, During the summer it disappears spontaneously, or may be soon removed by proper applications, but is apt to return again early in the ensuing spring, and continues so to do for several succe ive years. When the scales have been removed, and the disease is about to go off, the small patches have a shining appearance, and they exhibit a dark red intermixed with somewhat of a blueish colour for many days or even weeks before the skin is restored to its usual state. In the vee nereal disease there is an eruption which very much resembles the psoriasis guttata, the only diflerence being a slight degree of scaline , and a different shade of colour in the patches, approaching to a livid red, or very dark rose colour, The patches vary in their extent, from the section of a pea, to the size of a silver penny, but are not exactly circular, They rise at first very liutlle, if at all, above the cuticle. As soon, however, as the scales appear on them, they become sensibly elevated; and sometimes the edge or circumference of the patch is higher than the little scales in its centre. This eruption is usually seen upon the forehead, breast, between the shoulders, or in the inside of the fore-arms, in the groins, about the inside of the thighs, and upon the skin covering the lower part of the abdomen. The syphilitic psoriasis guttata is attended with, or soon followed by, an uiceration of the throat. It appears about six or eight weeks after a chancre ee been healed by an ineffectual course of mercury. A similar appearance takes place at nearly the same pes riod, in some cases where no local symptoms had been noticed. When a venereal sore is in a discharging state, this eruption, or other secondary symptoms, often appear much. later than the period above mentioned. They may also be kept back three months, or even longer, by an inefficient application of mercury. If no medicines be, employed, the syphilitic form of the psoriasis guttata will proceed during several months, the number of the spots increasing, and their bulk being somewhat enlarged, but without any other material alteration. The psoriasis diffusa spreads into large patches, irregularly circumscribed, reddish, rough, and chappy, with scales interspersed. It com~ mences, in general, with numerous minute asperities, or elevations of the cuticle, more perceptible by the touch than by sight. Upon these, small distinct scales are soon after formed, adhering by a dark central point, while their edges may be seen white and detached. the course of two or three weeks all the inter. vening cuticle becomes rough and chappy, appears red, and raised, and wrinkled, the lines of the skin sinking into deep furrows. The scales which form among them are often slight, and repeatedly exfoliate. Sometimes, without any previous eruption of papule, a large portion of the skin becomes dry, harsh, cracked, reddish, and scaly, as above described. In other cases, the disorder commences with separate patches of an uncertain form and size, some of them being small, like those in the psoriasis guttata, some much larger. The patches gradually expand till they become confluent, and nearly cover the part or limb affected. Both the psoriasis guttata and diffusa likewise occur as a sequel of the lichen simplex. This transition takes place more certainly after frequent returns of the lichen. The parts most affected by psoriasis diffusa are the cheeks, chin, upper eye-lids, and corners of the eyes, the temples, the external ear, the neck, the fleshy parts of the lower extremities, and the fore-arm, from the elbow to the back of the hand, along the supinator muscle of the radius. The fingers are sometimes nearly surrounded with a loose scaly incrustation; the nails crack and exfoliate superficially. The scaly patches likewise appear, though le frequently, on the forehead and scalp, on the shoulders, back, and loins, on the abdomen, and instep. This disease occasionally extends to all the parts above mentioned at the same time; but, in general, it affects them succe ively, leaving one place free, and appearing in others; sometimes, again, returning to its first situation, The psoriasis diffusa is attended with a sensation of heat, and with a very troublesome itching, especially at night. It exhibits small], slight, distinct scales, having le disposition than the Jepra to form thick crusts, The chaps or fi ures of the skin, which usually makes a part of this complaint, are very sore and painful, but seldom discharge any fluid. When the scales are removed, by frequent washing,’ or by the application of unguents, the surface, though raised and uneven, appears smooth and shining; and the deep furrows of the cuticle are lined by a slight scaline , Should any portion of the diseased surface be forcibly excortated, there i ues out a thin lymph, mixed with some drops of blood, which slightly stains and stiffens the linen, but soon concretes into a thin dry scab; this is again succeeded by a white scaline , gradually increasing, and spreading in various directions. As the complaint declines, the roughne , chaps, scales, . disappear, and a new cutiele is formed, at first red, dry, and shrivelled, but which, in two or three weeks, acquires the proper texture.y The duration of the psoriasis diffusa is from one to four months. If, in some constitutions, it does not then disappear, but becomes, to a, certain degree, permanent, there is at least an aggravation or extension of it, about the usual period of its return. In other cases, the disease, at the vernal returns, differs much as to its extent, and also with respect to the violence of the preceding symptoms. ‘The eruption is, indeed, often confined to a single scaly patch, red, itching, and chapped, of a moderate size, but irregularly circumscribed. ‘This solitary patch is sometimes situated on the temple, or upper part of the cheek, frequently on the breast, the calf of the leg, about the wrist, or within, and a little below the elbow joint, but especially at the lower part of the thigh, behind. It continues in any of these situations several months without much observable alteration, The complaint denominated with us the bakers itch is an appearance of the psoriasis diffusa on the back of the hand, commencing with one or two small, rough, scaly patches, and finally extending from the knuckles to the wrist. The rhagades, or chaps and fi ures of the skin, are numerous about the knuckles and ball of the thumb, and where the back of the hand joins the wrist. ‘They are often highly inflamed, and painful, but have no discharge of fluid from them. The back of the band isa little raised or tumefied, and, at an advanced period of the disorder, exhibits a reddish, glo y surface, without crusts or numerous scales. However, the deep furrows of the cuticle are, for the most part, whitened bya slight scaline , This complaint is not general among bakers; that it is only aggravated by their busine , and affects those who are otherwise disposed to it, may be concluded from the following circumstances: 1. It disappears about midsummer, and returns in the cold weather about the beginning of the year: 2. Persons constantly engaged in the busine , after having been once affected with the eruption, sometimes enjoy a respite from it for three or four years: When the busine is discontinued, the complaint does not immediately cease. The grocers itch has some affinity with the bakers itch, or tetter; but, being usually a pustular disease at its commencement, it properly helongs to an- other genus. Washerwomen, probably from the irritation of soap, are liable to be affeeted with similar scaly disease on the hands and arms, sometimes on the face and neck, which, in particular constitutions, prove very troublesome, and of long duration. The psoriasis gyrata is distributed in narrow patches or stripes, variously figured 5 soime of them are nearly longitudinal; some circular, or semicircular with vermiform apperdages; some are tortuous, or serpentine; others like earth-worms or leeches; the furrows of the cuticle, being deeper than usual, make the re~ semblance more striking, by giving to them an annulated appearance. There is a separation of slight scales from the diseased sartace, but no thick iocrustations are formed. ‘Tie uniform disposition of these patches is singular; i have seen a large circular one situated on each breast above the papilla; and two or three others of a serpentine form, in analogous situations along the sides of the chest. ‘The back is often variegated in like manner, with convoluted tetiers, similarly arranged on each side of the spine. They likewise appear, in some Cases, on the arms and thighs, intersecting each other in various directions. A slighter kind ef this coms plaint affects delicate young women and children in small scaly circles or rings, little disco~ loured; they appear on the cheeks, neck, or upper part of the breast, and are mostly confounded with the herpetic, or pastular ringworm. The psorfsis gyrata has iis remi ions and returns, like the psoriaris diffusa; it also exhibits, in some cases, patches of the latter disorder on the face, scalp, or extremities, while the trunk of the body is chequered with the singular figures above described. Psoriasis palmar i a.’ Oue very obstinate species of tetter is nearly confined to the palm of the hand. It commences with a small, harsh, or scaly patch, which gradually spreads over the whole palm, and sometimes appears in a slighter degree on the inside of the fingers and wrist. The surface feels rough from the detached and raised edges of the scaly laming; its colour often changes to brown, or black, as if dirty; yet the most diligent washing produces no favourable effect. The cuticular furrows are deep, and cleft at the bottom longitudinally, in various places, so as to bleed on stretching the fingers. A sensation of heat, pain, and stiffne , in the motions of the hand, attends this complaint. It is worst 1m winter or spring, and occasionally disappears in autumn or summer, leaving a soft dark-red cuticle; but many persons are troubled with it for a series of years, experiencing only very slight remi ions, Every return or aggravation of it is preceded by an increase of heat and dryne , with intole- rable itching. Shoemakers have the psoriasis palmar i a locally, from the irritation of the wax they so constantly employ. In braziers, tinmen, silversmiths, . the complaint seems long predisposition to it from a weak, languid, hectical state of the constitution may give effect to different occasional causes. Dr. Will an has observed it in women after lying-in; in some persons it is connected, or alternates with arthritic complaints. When the palms of the hands are affected as above stated, a similar appearance often takes place on the soles of the feet; but with the exception of rhagades, or fi ures, which seem le liable to form there, the feet being usually kept warm and covered. Sometimes, also, the psoriasis palmar i a is attended with a thickne of the preputium, with scaline , and painful cracks. ‘hese symptoms at last produce a phymosis, and render connubial intercourse difficult, or impracticable; so great, in some cases, is the obstinacy of them, that remedies are of no avail, and the patient can only be relieved by circumcision. Lhis affection of the praeputium is not exactly similar to the venereal appearance; but rhagades or fi ures, and indurated patches within the palm of the hand, take place in syphilis, and somewhat resemble the psoriasis palmar i a. The venereal patches are, however, distinct, white, and elevated, having nearly the consist- ‘ence of a soft corn. From the rhagades, there is a slight discharge, very offensive to the smell. ‘x he soles of the feet are likewise, in this case, affected with the patches, not with rhagades. When the disease yields to the operation of mercury, the indurated portions of cuticle separate, and a smovth new cuticle is found formed underneath. The fingers and ‘toes are not affected with the patches, . in venereal cases.