Cutaneous Manifestations of Diabetes Mellitus: A Review

Abstract

Diabetes mellitus is a widespread endocrine disease with severe impact on health systems worldwide. Increased serum glucose causes damage to a wide range of cell types, including endothelial cells, neurons, and renal cells, but also keratinocytes and fibroblasts. Skin disorders can be found in about one third of all people with diabetes and frequently occur before the diagnosis, thus playing an important role in the initial recognition of underlying disease. Noninfectious as well as infectious diseases have been described as dermatologic manifestations of diabetes mellitus. Moreover, diabetic neuropathy and angiopathy may also affect the skin. Pruritus, necrobiosis lipoidica, scleredema adultorum of Buschke, and granuloma annulare are examples of frequent noninfectious skin diseases. Bacterial and fungal skin infections are more frequent in people with diabetes. Diabetic neuropathy and angiopathy are responsible for diabetic foot syndrome and diabetic dermopathy. Furthermore, antidiabetic therapies may provoke dermatologic adverse events. Treatment with insulin may evoke local reactions like lipohypertrophy, lipoatrophy and both instant and delayed type allergy. Erythema multiforme, leukocytoclastic vasculitis, drug eruptions, and photosensitivity have been described as adverse reactions to oral antidiabetics. The identification of lesions may be crucial for the first diagnosis and for proper therapy of diabetes.

ISPAD Clinical Practice Consensus Guidelines 2018: Other complications and associated conditions in children and adolescents with type 1 diabetes

“…Initial skin changes can be subtle and manifest only as thickening of skin. This can be easily missed by visual inspection and palpation of areas used for injection is recommended to appreciate the soft, lipoma‐like nodules …”

“…Other diabetes‐associated skin conditions include granuloma annular, diabetic dermopathy, acquired perforating dermatosis, and bullosis diabeticorum, or diabetic bulla. There are also other skin disorders that occur more frequently in diabetic individuals like pruritis, xerosis, lichen planus, finger pebbles, and skin tags . Hyperglycemia leads to important metabolic and immunological alterations, so that people with diabetes tend to be more susceptible to skin infections …”

“…105 to appreciate the soft, lipoma-like nodules. 106 Injecting insulin into lipohypertrophic subcutaneous tissue can reduce insulin absorption by up to 25% and alter its duration of action. 107 Individual variability in insulin action is significantly higher in those with lipohypertrophy compared to those without.…”

Levels of wound calprotectin and other inflammatory biomarkers aid in deciding which patients with a diabetic foot ulcer need antibiotic therapy (INDUCE study)

“…Diagnosis of diabetic foot ulcer infection continues to rely on symptoms, principally pain, and signs, including erythema, warmth, oedema and discharge. However, pain may be absent due to concomitant neuropathy and signs may be attenuated by vasculopathy . Failure to treat mild infection with antibiotics risks progression to severe infection and amputation.…”

Functioning pituitary tumours: Hints from the skin

“…Diabetes mellitus associated with endocrine conditions involves a large area of complications including the skin: necrobiosis lipoidica diabeticorum, difficulties in wound healings, persistent infections, diabetic dermopathy (aggravated by diabetic neuropathy or vasculopathy/angiopathy), pruritus, acanthosis nigricans as sign of insulin resistance (7,26,27). Persistent high glucose affects each skin cell (27). Diabetes therapy like insulin may cause lypoatropy etc.…”