Is the course of psoriasis influenced by the seasons?
As a rule, yes; there is a natural tendency for the disease to become less active or to disappear altogether during the warm months.
What is known in regard to the etiology of psoriasis?
The causes of the disease are always more or less obscure. There is often a hereditary tendency, and the gouty and rheumatic diathesis must occasionally be considered potential. In some instances it is apparently influenced by the state of the general health. It is a rather common disease and is met with in all walks of life.
Is psoriasis contagious?
No. In recent years the fact of its exhibiting a family tendency has been thought as much suggestive of contagiousness as of heredity.
What is the pathology?
According to modern investigations, it is an inflammation induced by hyperplasia of the rete mucosum; and it is beginning to be believed that this hyperplasia may have a parasitic factor as the starting-cause.
With what diseases are you likely to confound psoriasis?
Chiefly with squamous eczema and the papulo-squamous syphiloderm; and on the scalp, also with seborrhœa. It can scarcely be confounded with ringworm.