Gangrene unlikely with prediabetes

Dear Dr. Roach: Can you explain diabetes and gangrene? I am prediabetic and the second toes on both feet have some tiny black spots on them. I will see my primary care physician soon.

S.R.

Answer: Gangrene is a name for localized death of body tissues. There are several different types.

Gas gangrene is a rapid, life-threatening infection caused by virulent microorganisms, such as group A streptococci or Clostridium perfringens.

Gas gangrene is fortunately uncommon to see these days, as it is often a complication of delayed treatment of wounds.

It is called gas gangrene because the bacteria make gas, which can be felt under the skin. This is usually very painful.

Treatment is rapid and extensive surgery along with antibiotics, and hyperbaric oxygen is a sometimes-useful additional treatment.

This is the type of gangrene least associated with diabetes.

Dry gangrene is caused by poor blood flow, usually to an extremity.

People with longstanding, severe diabetes are more at risk for this due to damage to both small and large blood vessels. The skin appears dark and dry.

Treatment usually includes surgery to improve the blood supply if possible; without it, the damaged tissues won’t heal.

Wet gangrene is a lifethreatening emergency requiring immediate surgery.

People with diabetes and nerve damage (neuropathy) are at higher risk for this, because they can injure themselves without knowing it.

The tissue appears wet, swollen and blistered, and may have a bad odor.

While dark spots on the toes could possibly be gangrene, it would be very unlikely in a person with prediabetes.

Your primary care physician or diabetes educator should be instructing you on what to look for on your feet (you should do a quick check every day) and to come in promptly for any worrisome signs.

People with diabetes may also benefit from regular foot care from a podiatrist, who can help prevent foot problems from developing.