Page:Skin Diseases of Children.djvu/60

ration is slight even in warm weather. Upon the extensor aspect of the extremities the epidermis presents often a peculiar serpentine appearance, resulting from the cracking of the horny layer into polygonal plates, which in time assume a dirty gray or greenish tint. These plates adhere by the central portion,

Fig. 17.—Ichthyosis.

while the margin tends to separate from the underlying skin. Around the elbows and knees the natural wrinkles are greatly intensified, and the breaking of the horny epidermis occasions a large number of concentric, whitish lines separating rows of warty elevations. As a rule the flexures of the joints, axillæ, groins, genitals, palms, and soles are but slightly if at all