(2) A distinct arrangement in lines in direction varying with the topography is observable in most cases.
(3) The colour is either pale red or distinctly yellowish.
(4) Instead of a fine pityriasic desquamation being always present, this is only distinct on the legs, sometimes just recognisable on the thighs and arms, while on the trunk it is absent, the surface being usually quite smooth.
(5) The presence of papules I have not observed, except at the commencement of Case 4.
(6) There is distinct infiltration in a large proportion of the patches, perceptible to the touch, though not to the eye.
The resemblances are: the absence of conspicuous pruritus, and there is often none; the occurrence in patches; the slow evolution; a pale redness; in many cases an extraordinary resistance to treatment. These are not enough to establish identity, but I confess that in my opinion they show greater resemblance to the affection I am describing than they do to psoriasis, and certainly my nine male cases would never suggest to any one a resemblance to psoriasis, and I should strongly demur to class them under parapsoriasis as a covering term.
Histological Note by George Pernet.
A piece of skin was removed from the extensor surface of the right forearm of the male case, aged 32 years (a Jewish tailor), where the more recent patches had appeared. Clinically there was practically no infiltration to be felt in that situation. The specimen was hardened in alcohol, cut in celloidin, and stained in various ways. The microscopical appearances were as follows:
Epidermis.—The stratum granulosum was either atrophied or absent. The stratum lucidum was absent except for traces here and there. The epidermis generally showed a slight amount of œdema.
Corium.—The vessels were dilated, with some cellular infiltration about them. The collagen appeared to be normal, with the exception of slight œdema, but the elastin was apparently reduced in quantity, especially in the papillary layer, and it was to some extent fragmented in places. It should be mentioned that the specimen was stretched on a small piece of cork in the process of hardening. The elastin stained, however, much as in the normal condition.