Diabetes mellitus is a complex metabolic condition that impacts various aspects of health, including the skin.

One frequently reported symptom among individuals with diabetes is persistent itching, which may occur even in the absence of visible rashes or allergy signs.

Causes of Itchy Skin in Diabetes

A multitude of factors contribute to pruritus (itching) in people living with diabetes, often linked to elevated blood sugar levels and associated complications.

1. Dry Skin and Poor Circulation

Chronic hyperglycemia leads to decreased fluid retention in skin cells, resulting in dryness and flakiness. The skin barrier becomes compromised, increasing vulnerability to irritation and itch. Additionally, diabetes impairs blood circulation, especially in extremities like the feet and lower legs, limiting nutrient and oxygen delivery to the skin. This diminished circulation further exacerbates dryness and causes uncomfortable itching, often concentrated in the lower limbs.

2. Peripheral Neuropathy and Nerve Damage

Diabetic polyneuropathy, or peripheral neuropathy, is a common complication characterized by nerve fiber damage. This impairs sensory function and manifests early as abnormal sensations including itching, prickling, or mild burning. Cytokines and inflammatory mediators released prior to nerve injury can directly stimulate skin nerves, producing itch sensations. This neuropathic itch may persist even without visible skin changes, making diagnosis challenging.

3. Infections

People with diabetes have a weakened immune defense, which increases susceptibility to skin infections. Bacterial infections such as boils or carbuncles and fungal infections like Candida albicans thrive in warm, moist skin folds and damaged skin areas. These infections commonly cause localized itching accompanied by redness, swelling, and irritation, demanding prompt treatment to prevent serious complications.

4. Allergic Reactions to Medications

Certain diabetic treatments, including medications and injectable insulin, can provoke allergic reactions in some individuals. These reactions often present with itching, swelling, or rashes localized around injection sites or other skin regions.

5. Dehydration and Systemic Effects

High blood sugar causes the body to expel excess glucose through increased urination, which may lead to dehydration. Dehydrated skin becomes rough, dry, and prone to itching from loss of moisture. In severe cases, diabetes-related kidney or liver dysfunction can contribute to widespread itching due to systemic metabolic disturbances.

Mechanisms Behind Diabetes-Related Itching

Recent research highlights two principal mechanisms underlying itch in diabetic patients: dermatological factors like xerosis (skin dryness) and neurological factors related to damaged peripheral nerves. Diabetic neuropathy is often the main driver of persistent itching in long-standing diabetes.

At the molecular level, inflammatory cytokines such as interleukins (IL-31, IL-4) and nerve growth factors stimulate receptors like TRPV1 and TRPA1 on sensory nerve fibers, lowering the threshold for itch perception. Elevated oxidative stress, commonly observed in diabetes, exacerbates inflammation and contributes to nerve sensitization, perpetuating itch signals.

Managing and Preventing Itchy Skin in Diabetes

Optimal management of itchy skin in diabetes revolves around maintaining stable blood glucose levels to prevent complications. In addition to glycemic control, several supportive measures are crucial:

- Daily skin inspection can detect early signs of infection or irritation.

- Gentle skin cleansing with lukewarm water and moisturizing with fragrance-free, ceramide-rich creams help restore the skin barrier.

- Preventing dehydration and maintaining good hydration supports skin health.

- Prompt treatment of infections with appropriate antibiotics or antifungals is essential.

- Physical activity improves blood flow, which can mitigate dryness and neuropathic symptoms.

Dr. Krystyna Stefaniak, MD, PhD, a specialist in dermatology and neurobiology, explains, "Itch in diabetes is multifactorial, primarily due to dry skin and peripheral neuropathy. Understanding the neuroinflammatory pathways involved provides new opportunities for targeted therapies to improve patient quality of life."

Itchy skin is a common and often underappreciated complication of diabetes, resulting from a combination of skin dryness, impaired circulation, nerve damage, infections, and medication reactions. Effective prevention and treatment strategies rely on comprehensive diabetes management and attentive skin care. Recognizing itchy skin as an early warning sign allows timely intervention to prevent more serious complications and improve comfort and well-being in individuals living with diabetes.