scab. 1  An incrustation over a sore, wound, vesicle, or pustule, formed during healing. 2  The mange, especially when it appears on sheep. 3  Any of several different diseases of potatoes producing pits and other damage on their surface, caused by streptomyces bacteria (but formerly believed to be caused by a fungus).
Diabetes complications from fungus infections in the toenails and fingernails can lead to amputations of the entire limbs. To understand how serious fungal toenails can be to a diabetic, you must first understand how diabetes affects the body.
This is the case of people with HIV / AIDS, people under steroid treatments, and people taking chemotherapy. People with diabetes also tend to develop fungal infections. Very young and very old people, also, are groups at risk.