Cutaneous manifestations of diabetes
Content prepared,
with permission, from the autumn 2005 issue of Diabetes
Wise
Necrobiosis
lipoidica
- Inflammatory skin disorder of unknown cause
- Up to 75% of people who have NL will develop diabetes
- M : F = 1 : 3
- Classically asymptomatic (many insensate) and located pretibialor or medial malleolar areas.
- Lesions are oval or irregularly shaped, indurated plaques with elevated margins with either red-brown or violaceous pigmentation. Gradually become brownish yellow with central depressed atrophy
- Treatment includes potent topical steroids, intralesional steroids Rarely systemic steroids
- Topical or injectable corticosteroids avoided if ulcers present
Acanthosis nigricans
- Reactive skin pattern
- Associated with endocrinopathy, malignancy (particularly GI) and some drugs
- Symmetrical hyperpigmented velvety plaques in the body folds
- Association between AN, obesity, hypertension, ischaemic heart disease and type 2 diabetes
- Generally two groups of patients
- Type A is more common in young (particularly black) women
with AN, primary amenorrhoea with hyper
testosteronaemia, virilisation, increased somatic growth, hyperglycaemia and hyperinsulinaemia with insulin resistance due to a congenital defect of insulin receptors. - Type B consists of patients who are older with features suggesting other autoimmune diseases, including raised ESR, proteinuria, hypocomplementaemia with antinuclear and anti-DNA antibodies.
- Type A is more common in young (particularly black) women
with AN, primary amenorrhoea with hyper
- AN is frequently asymptomatic, but lesions may become malodorous
- Treatment should be aimed primarily at weight reduction, keratolytics (e.g. topical retinoids) +/- antibacterial soaps
Cutaneous infections associated with DM
No strong evidence to link diabetics with propensity to infection in general. But, some infections are more common and may be more severe in diabetics
Skin infections due to Staph aureus and group A Strep haemolyticus
- Folliculitis, furunculosis and abscess formation occur in people with poorly controlled diabetes
- Erythrasma (superficial infection of the skin at flexural sites) is due to the aerobic, Gram-positive Corynebacterium minutissimum
- Fungal infections encountered in patients
with diabetes include dermatophytes (tinea pedis, onychomycosis),
candidiasis (mucosal and cutaneous) and mucormycosis with necrotising
nasopharyngeal infections. - Those at higher risk are patients with sensory neuropathy and peripheral vascular disease.
- Onychomycosis (fungal nail infection) can damage surrounding
skin and allow bacterial entry
- Often requires systemic antifungal therapy
Granuloma annulare
- Unknown aetiology
- Ring of small, smooth, flesh-coloured or erythematous papules
- Dorsum of the hands, feet and fingers
Diabetic bullae
- Approx 0.5% of people with diabetes develop diabetic bullae (bullosis diabeticorum)
- Bullae occur spontaneously in adults
- Particularly long standing DM with neuropathy
- M > F, feet and lower leg
- Sometimes mildly painful or associated with a mild burning
- Heal in a few weeks without scarring
- Probably vascular aetiology
Diabetic
dermopathy (shin spots)
- Occur in up to 40% of people with diabetes
- Is the most common cutaneous manifestation of diabetes (not pathognomic)
- Initial dull red papules, 0.5-1cm in diameter
- Anterior aspect of the lower legs
- Generally bilateral and asymptomatic
- Evolve into crops of oval circumscribed, atrophic, slightly depressed, brownish lesions
- Spontaneously resolve, eventually healing with scar formation.
- Probably due to microangiopathy
- Some studies have shown a significant correlation with other
complications
- Retinopathy, neuropathy and nephropathy
Diabetic thick skin (finger pebbles)
- Scleroderma-like skin change
- Thickening and induration
- Especially dorsum of the fingers
- Leads to clawing
- Correlation with angiopathy.
‘Finger pebbles’ = multiple, tiny, flesh-coloured papules on the dorsum of the fingers, knuckle pads and periungual areas.
Scleredema
- Poorly demarcated scleroderma-like induration of the
skin and subcutaneous tissue of the upper
back, neck and proximal extremities. - Onset correlates with the duration of DM and with presence
of
microangiopathy.
Eruptive xanthomas
- Widespread yellow to red papules
- Linear array in response to trauma
(Köbner phenomenon) - Poorly controlled DM who have massive hypertriglyceridemia.
- Most commmonly over
the buttocks, shoulders and extensor surfaces of extremities
Acquired
perforating dermatosis
Kyrle’s disease (KD)
- Rare disorder of keratinisation
- Sscattered or grouped keratotic
papules on the extremities and trunk - Frequently with renal failure
Content, with permission, from 2005 issue of Diabetes Wise by Dr Íomhar O' Sullivan 02/01/2006. Reviewed by Dr ÍOS 30/05/2005, 15/01/2007. Next review 15/01/2008.
