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.
The fungus Microsporum gypseum can also sometimes cause tinea capitis. This fungus is common in soil and may be transferred to humans by contact with infected animals. You can also get ringworm from pets that carry the fungus, and cats in particular are common carriers.