PSORIASIS Psoriasis is a chronic affection of the skin with frequent relapses, characterized by light red papules or plaques which are covered with silvery scales. The scales arc loosely connected and become easily detached through scratching, and underneath the scales appears the inflamed, light red, punctiforrn, bleeding skin.
Clinical forms roundish patches, from a pin head to a dollar piece in size, which gradually grow larger and may become confluent. They never exudate, itch but rarely, exhibit only slight inflammation and are covered with silvery scales. According to the size or the confluent character of the patches we distinguish psoriasis punctata, guttata, annularis, gyrata, etc.
Psoriasis attacks with great predilection the extensor surfaces of the extremities, the hairy part of the head and the skin over the sacral bone; the nails also mayt become fissured and brittle. The affection is characterized by the absence of pruritus and other symptoms, by the presence of silvery scales and by its chronic course. It recurs in spasmodic paroxysms and may last through life. According to Nielsen in 44 per cent. of all cases it commences before the fifteenth year, generally after the fifth or sixth. It may, however, also appear in earliest infancy (on the 3:St day, Rine; in the fourth month, Neumann). In children it runs a relatively benign course; severe cases have not been as yet reported. There is a total absence of complaints, and only as fresh relapses occur, there is sometimes con siderable pruritus. It is often very strongly developed on the hairy part of the head in childhood, thick scaly masses being formed there.
Pathological A nat om y The microscopic picture shows a broadening of the stratum corneum and a thickening of the rete Malpighii with considerable proliferation. The papillai are enlarged, swollen and (edema tous, and there is considerable dilatation of the papillary ves sels. The VCSSeiS of the corium are dilated, with slight small celled infiltration which quite corresponds to the clinical pic ture of absence of coarseness in the psoriatic plaques.
The etiology of psoriasis is en t ir el y unknown (diathesis? neuropathic etiology? mycotie causes?). Quite a series of eases that occurred in childhood have been published, in which psori asis has appeared following auri cular eczema and piercing of the lobe (Henoch, Neumann.). Whether the occurrence of psori asis after vaccination has any connection with the latter, is not proved.
Nor do we know whether heredity has anything to do with it, whether in family transmissions it is congenital, whether the tendeney is inherited, or whether there is a simple infection.
Prognosis.—The fact that psoriasis is a chronic affeetion which is difficult to cure does not make the prognosis very favorable. Even though it causes no trouble during childhood, it should be remembered that an afflicted child may never lose the eruption for the rest of its life. diagnosis of the light form occurring in childhood is much easier than in the adult, as the silveryscales and the bleeding spots which occur after scratching them off, excludes any possible confusion.
Treatment.—The object of the treatment is to influence the eruption by internal medication, to remove the scales by, external measures and to effect a healing of the exposed surfaces by medicinal agents.
Of internal 'medicines only arsenic is to be considered. In younger children it is administered as Fowler's solution 2.2 Cm. (i dr.) aq. destill. S.0 c.c. (2 dr.) (5 gtt. t.i.d.), or in the form of injections (liquor pot. arseni cosi, aqua destill. aa 5.0 c.c. (1?-; dr.) 1 unit of the Fravatz syringe up to 15 units, according to age), in older children, when anntia is present, in the form of the well-known pills of iron and arsenic. Generally speak ing, the arsenic treatment is not reliable; still more uncertain is the efficacy of the substitutes sodium cacodylatc and atoxyl. Under cer tain circumstances the diet has to be changed, an improvement being frequently effected through a change in nutrition.