Page:Skin Diseases of Children.djvu/43

Rh appear as though "stuck on" to the cutaneous surface. When thoroughly dried these crusts fall, and even when picked or rubbed off they leave no ulcerated surface, but merely a small hyperæmic area.

It is only in exceptional cases, however, that this natural and characteristic evolution of the lesion can be observed, for in children, especially, the irritation of the lesions usually provokes scratching, which changes their clinical appearance, and a little blood mingled with the purulent secretion gives rise to



the formation of a dark crust or scab. Upon the extremities, especially the legs, friction of the clothing, dirt, and constant scratching frequently inflame the lesion, and a dark crust upon a superficial ulceration with a narrow red areola is produced, which has generally been described as a distinct skin affection under the name of ecthyma. These ecthymatous pustules, common in cachectic children, are often associated with the characteristic lesions of contagious impetigo upon the face and hands and are evidently of similar if not identical origin.