Skin Changes in Diabetes Mellitus

ICD-11

EL3Y

Synonyms

None.

Epidemiology

80% of patients with diabetes mellitus have skin changes.

Definition

The spectrum of skin changes seen as a result of hyperglycaemia and its multiple effects on the body.

Aetiology & Pathogenesis

Due to hyperglycaemia, there are pathological changes in the circulation, nerves and an increased tendency to infection, with reduced wound healing. Depending on the duration of the disease in type I vs type II diabetes.

Signs & Symptoms

Microangiopathy:

- Pretibial pigmented patches (PPP): small, poorly-defined brown macules over shins.

- Rubeosis faciei: persistent facial erythema.

Macroangiopathy:

- Peripheral arterial occlusion: intermittent claudication, calves and feet pale or livid and cold, absent or reduced pulses in feet, sometimes ulcers or delay in wound healing.

Polyneuropathy:

- Neuropathic ulceration: indolent painless ulcers with hyperkeratotic border, primarily on heels, tips of toes (diabetic foot; acroosteopathia ulceromutilans). See chapter 5.1.4 Pressure sore.

Granulomatous disorders:

- Necrobiosis lipoidica: primarily on shins, oval sharply demarcated yellow-red plaques with central glassy white-yellow area, mostly asymptomatic, may ulcerate.

- Disseminated granuloma annulare: primarily on trunk, asymptomatic papules and plaques, sometimes confluent and often with prominent border.

Infections:

- Candidiasis: most often intertriginous (groins, rima ani, submammary, umbilicus), also involves mouth, genitalia (balanitis, vulvovaginitis), nails.

- Overgrowth of staphylococci: Folliculitis and furuncles: usually on trunk.

Others:

- Generalised pruritus: always rule out diabetes mellitus in patients with unexplained diffuse persistent pruritus.

- Nodular prurigo: pruritic papules with central excoriations, usually on shoulders and arms (females more than males).

- Bullosis diabeticorum: large acral blisters.

Localisation

See above.

Classification

According to symptoms.

Laboratory & other workups

Swabs to exclude an infection (bacterial or mycotic) may be required. Doppler ultrasound. Neurological examination.

Dermatopathology

Not usually necessary and generally to be avoided, due to impaired wound healing. However, granulomatous diseases of the leg and widespread localization needs confirmation.

Course

Depends on the underlying cause. Generalised pruritus tends to persist, even despite good glycaemic control.

Complications

Infection, particularly in the context of the diabetic foot. This may even include osteomyelitis. High dose antibiotics according to resistogram. Amputation should be considered as a last resort.

Diagnosis

Always relies on a secure diagnosis of diabetes mellitus.

Differential diagnosis

Depends on individual condition (see above symptoms).

Prevention & Therapy

Optimise glycaemic control. Regular diabetology/dermatology follow-up in high-risk patients. Treat microangiopathy. Necrobiosis diabeticorum difficult to treat (topical tacrolimus, TNF alpha blocker off label). Orthopedic shoes.

6.2.1 Skin Changes in Diabetes Mellitus