Introduction
It is estimated that 30% of patients with diabetes mellitus will experience a skin problem at some stage throughout the course of their disease. Several skin disorders are more common in diabetic patients, particularly those due toinfectionsuch ascandidaandimpetigo.Patients with type 2 diabetes also have twice the risk ofdevelopingthe commonscalydisease,psoriasis, as non-diabetics.
年代kin conditions associated with diabetes mellitus
年代pecific skin conditions associated with diabetes mellitus are described below.
What is diabetes mellitus?
Diabetes mellitus constitutes a collection of diverse disorders associated with an increase in bloodglucoseconcentration.
Diabetes is associated with impaired carbohydrate,protein, and fatmetabolismdue to insufficient secretion ofinsulinor target-tissueinsulin resistance. Complications of diabetes mellitus comprise bothmacrovascular(cardiovascular) andmicrovascular(retinopathy, nephropathy, orneuropathy)sequelae.
Type 1 diabetes mellitus is characterised by absolute insulin absence and is due toautoimmunebeta-cell destruction. It typically presents withacutesymptoms orketoacidosisin childhood or adolescence, and lifelong insulin therapy is mandatory.
Type 2 diabetes mellitus is a common disorder categorised byinsulin resistanceand relative insulin deficiency. Patients are oftenasymptomaticand are diagnosed through screening. Strong risk factors include older age, obesity, physical inactivity, priorgestationaldiabetes, pre-diabetes, non-white ancestry, family history of diabetes, andpolycystic ovarysyndrome. Modification of cardiovascular risk factors (eg,hypertensionanddyslipidaemia) are an important part of treatment, along with glycaemiccontrolto prevent microvascular complications.
Type 2 diabetes is the main cause of type 2 diabetes in children, who are usually over 10 years of age.Acanthosisnigricansaccompanies childhood diabetes in 90–95%.
Gestational diabetes is diagnosed if glucose intolerance is first recognised during pregnancy at 24–28 weeks ofgestation. Strong risk factors include advanced maternal age (more than 40 years), obesity, personal history of gestational diabetes or macrosomia affecting a previous child,polycystic ovary syndrome, non-white ancestry, and a family history of diabetes mellitus.
Other presentations of diabetes mellitus include diabetic ketoacidosis, hyperosmolar hyperglycaemic state, diabetic cardiovascular disease, diabetic kidney disease, diabetic neuropathy,diabetic foot, diabetic retinopathy, andmetabolic syndrome.
The increasingprevalenceof diabetes requires targeted screening for detecting diabetes and prediabetes in risk groups to prevent and mitigate the progression of the disease.
Diabetic dermopathy
Diabetic dermopathy is a skin condition characterised by light brown or reddish, oval or round, slightly indented scaly patches most often appearing on the shins. Although theselesionsmay appear in anyone, particularly after an injury ortraumato the area, they are one of the most common skin problems found in patients with diabetes mellitus. Diabetic dermopathy has been found to occur in up to 30% of patients with diabetes.
Diabetic dermopathy is sometimes also referred to as shin spots andpigmentedpretibialpatches. They resemblesolarlentigines.
Diabetic dermopathy
What causes diabetic dermopathy?
The exact cause of diabetic dermopathy is unknown but may be associated with diabeticneuropathicandvascularcomplications, as studies have shown the condition to occur more frequently in diabetic patients with retinopathy, neuropathy and nephropathy.
Diabetic dermopathy tends to occur in older patients or those who have had diabetes for at least 10–20 years. It also appears to be closely linked to increased glycosylatedhaemoglobin,血糖控制差的指标vels.
Because lesions often occur over bony parts of the body such as the shins, it is thought that diabetic dermopathy may also be a magnified response to injury or trauma to these areas. Studies have shown that shin spots have appeared in response to trauma with heat, cold or blunt objects in patients with diabetes.
What are the signs and symptoms?
糖尿病皮肤病病变最常出现on the shins. Less commonly lesions can be found on the front of the thighs, forearm, side of the foot, scalp and trunk. Features of lesions are:
- Round or oval-shaped
- Reddish-brown colour
- Initially scaly but then flattens out and becomes indented
- Commonly occur on both shins.
The presence of four or more lesions is almost always limited to patients with diabetes. People presenting with shin spots not already diagnosed with diabetes should undergo a further investigation to rule out the possibility of early diabetes.
What is the treatment for diabetic dermopathy?
Diabetic dermopathy lesions or shin spots are harmless. They usually do not require any treatment and tend to go away after a few years, particularly following improved blood glucose control.
Diabetic bullae
Diabetic bullae, also known as bullosis diabeticorum, are blister-like lesions that occur spontaneously on the feet and hands of diabetic patients. Although rare, diabetic bullae are a distinct marker for diabetes.
- Diabetic bullae are more common in men than women
- They areprevalentbetween the ages of 17 and 84 years.
- They are also more common in patients who have long-standing diabetes or multiple diabetic complications, particularly neuropathy.
The blisters are painless and can be from 0.5–17 centimetres in size. They often have an irregular shape. Two types of diabetic bullae have been defined.
- Intraepidermalbullae — these are blisters filled with clear, sterileviscousfluid and normally heal spontaneously within 2–5 weeks without scarring andatrophy.
- 年代ubepidermalbullae — these are less common and may be filled with blood. Healed blisters may show scarring and atrophy.
In most cases, diabetic bullae heal spontaneously without treatment. Patients should make sure the blister remains unbroken to avoid secondary infection.
Diabetic bullae
Diabetic stiff skin
Many patients with longstanding type 1 diabetesdevelopdiabetic cheiroarthropathy or diabetic stiff skin (digital sclerosis). This results in restricted mobility of the joints of their hands and stiff, waxy, thickened and yellowed skin. This is thought to be due to the reaction of glucose withproteinsin the skin and increased glycation end products. These patients may also suffer fromDupuytrencontracture(tendon tightening, which bends the fingers).
Diabetic stiff skin
Other dermatological conditions associated with diabetes
Other common conditions in diabetics arefootulcersandnecrobiosislipoidica.
Diabetics withrenalfailure are also prone toreactiveperforatingcollagenosisandKyrle disease.
- 年代cleroedema— a rare complication of type 2 diabetes causing skin thickening of the neck and upper back
- Disseminatedgranulomaannulare
- Eruptivexanthomaon the hands, arms, feet, legs, and buttocks associated with high levels ofcholesterolandtriglycerides
- Xanthelasma — multiple yellowish scaly patches on and around the eyelids
- 年代kin tags
- Vitiligo— an autoimmune skin problem sometimes associated with type 1 diabetes
- Acanthosis nigricans— darkening and thickening of skin folds, thought to be due to insulin resistance
- 渐进性坏死lipoidica— yellow, waxyplaqueson the shin
- Pruritus— this can have many causes, such as a yeast infection, dry skin, neuropathy or poor blood flow
- Cutaneousdysaesthesia— due to small fibre neuropathy
- Bacterialskininfections— including stye,boil,abscess,paronychia,cellulitis
- Fungal infections— particularlyCandida albicans
