Diabetic blisters

Skin changes in the course of diabetes are the result of complex metabolic and vascular disorders. The main pathogenetic mechanisms include:

1. Chronic hyperglycemia

• Excess glucose leads to protein glycation (the formation of so-called AGE – advanced glycation end products).
• This results in damage to collagen, elastin, and blood vessel walls.
• Nourishment of the skin and its ability to regenerate are impaired.

2. Diabetic microangiopathy

• Damage to small skin vessels causes hypoxia and increased susceptibility to injuries.
• Healing disorders and a tendency to superinfections occur.

3. Peripheral neuropathy

• Decreased sensation of pain and temperature promotes micro-injuries.
• Patients often do not notice minor skin damage, which becomes secondarily infected.

4. Immune disorders

• Diabetes impairs the function of neutrophils and macrophages.
• There is an increased susceptibility to bacterial (e.g., staphylococcal) and fungal (Candida, dermatophytes) infections.

The most common clinical entities referred to as "diabetic dermopathy":

• Diabetic dermopathy – brown spots and papules on the shins.
• Diabetic blisters (bullosis diabeticorum) – sudden, painless blisters on the feet and hands.
• Purulent skin infections – boils, folliculitis.
• Fungal infections of the skin and nails – especially on the feet.

It is worth noting: these changes occur more frequently with long-standing, poorly controlled type 1 and type 2 diabetes.

The clinical picture depends on the type of dermatosis, but there are some common features.

Characteristic symptoms:

• Papules and pustules – most commonly around hair follicles, with a tendency to enlarge.
• Blisters filled with serous fluid – tense, painless, without inflammatory erythema.
• Brown or reddish spots on the lower legs – 0.5–1.5 cm in diameter, often symmetrical.
• Itching and burning – especially with coexisting fungal infections.
• Tendency for hard-to-heal erosions and ulcers.

Location of changes:

• lower legs,
• feet and interdigital spaces,
• hands,
• groin area,
• buttocks.

Features distinguishing diabetic skin changes from acne vulgaris:

• Patient's age – diabetic skin changes most commonly occur in adults and the elderly, usually with a long history of metabolic disorders. Acne vulgaris primarily affects adolescents and young adults.
• Location of changes – in diabetes, typical areas are the lower legs, feet, interdigital spaces, groin, or buttocks. Acne is mainly located on the face, back, and chest, areas with high sebaceous gland activity.
• Healing process – diabetic changes heal slowly, often leaving pigmentation or erosions and have a tendency for infections. In acne, with proper treatment, the regeneration process is usually faster.
• Relation to glycemia – in diabetes, the severity of changes correlates with glucose levels and HbA1c values. Acne vulgaris does not show a direct connection with carbohydrate metabolism disorders.

Skin changes in diabetes tend to recur, especially with improper HbA1c levels.

Therapeutic management requires a multidisciplinary approach: diabetological, dermatological, and - in the case of complications - surgical.

1. Metabolic Control (Basis of Treatment)

• optimization of insulin or oral medication therapy,
• monitoring HbA1c (target <7% for most patients),
• weight reduction,
• low glycemic index diet.

Without glucose stabilization, topical treatment has limited effectiveness.

2. Topical Treatment

Depending on the diagnosis:

• Topical or systemic antibiotics - for bacterial infections.
• Antifungal medications - for skin and nail fungal infections.
• Barrier repair preparations - emollients, urea creams (5-10%).
• Specialized dressings - for erosions and ulcers.

3. Procedural Management (in selected cases)

For scars, post-inflammatory hyperpigmentation, or chronic lesions, aesthetic dermatology procedures may be considered, such as:

• Fractional laser therapy - to improve skin structure.
• Medical peels - to reduce hyperpigmentation.
• Regenerative therapies - stimulating skin regeneration.

Each procedure must be preceded by an assessment of the patient's general condition and diabetes control level.

4. Prevention

• daily foot skin check,
• avoiding injuries and tight footwear,
• proper hygiene and thorough drying of interdigital spaces,
• regular visits to a podiatrist for the so-called diabetic foot.

Changes referred to as "diabetic blisters" are a clinical signal of systemic metabolic disorders. In medical practice, they are treated not only as a dermatological issue but as an indicator of the degree of diabetes control and the risk of vascular complications.