In the severe variety—ichthyosis hystrix—in addition to scaliness there is marked papillary hypertrophy, forming warty or spinous patches. This type is rare, and, as a rule, the surface involved is more or less limited.
Are there any inflammatory symptoms in ichthyosis?
No. In fact, beyond the disfigurement, the disease causes no inconvenience; in those well-marked cases, however, in which the scales are thick and more or less immovable, the natural mobility of the parts is compromised and fissuring often occurs. In the winter months, in the severer cases, exposed parts may become slightly eczematous.
Does ichthyosis vary somewhat with the season?
Yes. In all cases the disease is better in the warm months, and in the mild forms may entirely disappear during this time. This favorable change is purely mechanical—due to the maceration to which the increased activity of the sweat glands gives rise.
Is the general health affected in ichthyosis?
No.
What course does ichthyosis pursue?
Chronic. Beginning in early infancy or childhood, it usually becomes gradually more marked until adult age, after which time it, as a rule, remains stationary.
What is the etiology?