8 Skin Changes Dermatologists Say Are Worth Mentioning to Your Doctor

Skin is often the first place metabolic changes show up — sometimes months before a blood test would catch anything. None of these changes mean you have diabetes on their own, but dermatologists say they’re common enough in people with blood sugar issues that they’re worth a mention at your next checkup.

What to watch for

• Acanthosis nigricans. Dark, velvety patches of skin, usually at the neck, armpits, or groin — one of the more recognized skin signs linked to insulin resistance.^[1]
• Diabetic dermopathy. Light brown, scaly patches, usually on the shins, sometimes called “shin spots” — thought to relate to changes in small blood vessels.
• Slow-healing cuts or sores. Elevated blood sugar can impair circulation and immune response, making even minor wounds take noticeably longer to close.
• Frequent skin infections. Recurrent fungal infections, styes, or boils can be a sign blood sugar is running high enough to affect immune defenses.
• Yellowish, thickened skin. Sometimes seen on the hands or feet, occasionally alongside stiff joints.
• Itchy skin without an obvious cause. Poor circulation and dry skin both linked to elevated blood sugar can present simply as persistent, unexplained itching.
• Blisters that appear without injury. Rare, but a recognized sign (bullosis diabeticorum) that dermatologists specifically look for in people with longstanding blood sugar issues.
• Waxy, thickened patches on the fingers or toes. Associated with longer-term elevated blood sugar and changes in collagen.

Roughly a third of people with diabetes will develop some kind of skin manifestation at some point, and skin changes are sometimes the detail that prompts a diagnosis in someone who didn’t have other obvious symptoms.^[1]

What this doesn’t mean

None of these signs are diagnostic on their own — skin changes have plenty of other causes, and having one of these does not mean you have diabetes. It means it’s worth mentioning to a doctor, especially alongside other risk factors like family history, weight changes, or increased thirst and urination. A simple blood test settles the question far better than a symptom checklist.

References

1. Kalus AA, et al., as summarized in “Dermatological Manifestations of Diabetes Mellitus and Its Complications.” Diabetology, 2025;6(3):18. Finding used: skin manifestations occur in a substantial proportion of people with diabetes, with acanthosis nigricans among the most recognized cutaneous markers of underlying insulin resistance, and skin findings sometimes preceding formal diagnosis. DOI: 10.3390/diabetology6030018. ↑︎

Kurt Greiner

Kurt is a digital strategist and IT professional blending emerging technology with practical application to help businesses and individuals streamline their digital presence. His current work focuses on the intersection of intentional living and technological resilience, exploring how individuals can leverage modern tools to navigate the second half of life with purpose.