A disease historically associated with malnourishment on sailing vessels may have a new, modern culprit: Bariatric surgery.

Getting a prompt diagnosis is always important ... You may be able to tell the spots on your skin are petechiae instead of a rash if you press on them, and they don’t turn lighter in color.

One way to help confirm the diagnosis is to press a water glass against the lesions. If they do not blanch (turn white), it is a positive sign of petechiae or purpura. Both also tend to develop ...