Prediabetic condition is a state where blood sugar is increased, yet, not increased enough to cause diabetes. A prediabetic or undiagnosed diabetic condition can be detected by observing the changing condition of skin. 

The skin symptoms that indicates prediabetic conditions are:

• Skin Patches: The appearance of yellow, red or brown patches, causing swelling and hardening of skin. It causes pain and itchiness around the skin.
• Skin Darkening: A dark patch on neck, underarms, or other parts of body, indicating excess of insulin in blood.
• Hardening and Thinking of Skin:  The skin around figures and toes becomes hard and thick, causing movement difficulties. Area on the back of hand, arms, knees, ankles, and elbows, become swollen, hard and thick.
• Blisters: In some prediabetic case, skin blisters may appear on hands, feet or legs.
• Wounds and sores: Increased blood sugar can cause nerve damage, which affects the body’s natural ability to heal wounds and sores.
• Itchy Skin Bumps: Red and yellow bumps may appear on buttocks, thighs, elbows or backside of knees, causing itchiness.
• Dryness and Itchiness: Skin infections and poor blood circulation can be caused because of increased blood sugar, leading to skin dryness and itching.
• Scales and Patches on Eyelids: These are caused by increased sugar level in blood.
• Skin Tags: A skin growth, which is not harmful, but an increased number of same indicates a rise in blood insulin.

Some of these symptoms are also common in skin diseases like psoriasis, a common condition in metabolic syndromes.