Page:Skin Diseases of Children.djvu/20

4 of the face and other hairy parts may present bald areas or appear completely denuded.

When first discovered the patch is usually tending to increase slowly in circumference, and the hairs at the margin of the disc are so loosened in their follicles that several can be pulled out at a time without giving the patient the slightest pain. Often the loose hairs will only be found on one side of the patch, and extension in this direction is certain to follow. Examined beneath the microscope these loose hairs will be found to be atro-



phied toward the root, and in some cases they will break near the surface of the skin. This breaking of the hairs does not leave a short, stiff stubble like that which is characteristic of the patches of ringworm, but as the broken-off roots of the affected hairs in alopecia areata project from the scalp near the margin of the patch, they may be noted as short, fine hair tapering downward and sometimes suggesting a crop of exclamation points.

The extent to which alopecia areata will develop in a given case it is difficult to determine in advance, but sooner or later in