Finger 'pebbles'. A dermatologic sign of diabetes mellitus

Diabetes mellitus and the skin

Diabetes is a debilitating, life-threatening disease accounting in 2015 for the death of 5 million people worldwide. According to new estimations, 415 million adults currently suffer from the disease, and this number is expected to rise to 642 million by 2040. High glucose blood levels also affect the skin among systemic organs, and skin disorders can often predict the onset of this metabolic disorder. In this review, we address the pathomechanistic effects of diabetes on the skin and give an overview on the most common skin diseases associated with diabetes.

Dermatologic manifestation of diabetes

With the rising incidence of diabetes mellitus (DM) in the US, it is of paramount importance that practitioners understand the complications of DM and how best to manage them. Diabetes affects every organ system and the skin is no exception. There are numerous cutaneous manifestations of DM that have similar etiologies and result from the same pathologic mechanisms as the internal complications of this disease state. In addition, skin manifestations may precede the diagnosis of diabetes. The present article reviews both the common and less common cutaneous manifestations of DM, including presenting lesions, pathogenesis, and management.

Skin signs in diabetes mellitus

Diabetes mellitus is the most common endocrine disorder with continuously increasing prevalence. Blood vessels, nerves, eyes, kidneys and skin are affected, which causes both an enormous financial burden and a reduced quality of life of the affected patients. Long-standing diabetes may impair skin homeostasis resulting in skin manifestations in at least one third of all diabetics. The skin involvement may be the first presenting sign of diabetes, thus the respective skin signs should lead to diabetes focused diagnostic. Besides, the skin signs may be considered as a marker for the course of the disease or for the success of therapeutic interventions.

Hyperinsulinemic diseases of civilization: more than just Syndrome X

Compensatory hyperinsulinemia stemming from peripheral insulin resistance is a well-recognized metabolic disturbance that is at the root cause of diseases and maladies of Syndrome X (hypertension, type 2 diabetes, dyslipidemia, coronary artery disease, obesity, abnormal glucose tolerance). Abnormalities of fibrinolysis and hyperuricemia also appear to be members of the cluster of illnesses comprising Syndrome X. Insulin is a well-established growth-promoting hormone, and recent evidence indicates that hyperinsulinemia causes a shift in a number of endocrine pathways that may favor unregulated tissue growth leading to additional illnesses. Specifically, hyperinsulinemia elevates serum concentrations of free insulin-like growth factor-1 (IGF-1) and androgens, while simultaneously reducing insulin-like growth factor-binding protein 3 (IGFBP-3) and sex hormone-binding globulin (SHBG). Since IGFBP-3 is a ligand for the nuclear retinoid X receptor alpha, insulin-mediated reductions in IGFBP-3 may also influence transcription of anti-proliferative genes normally activated by the body's endogenous retinoids. These endocrine shifts alter cellular proliferation and growth in a variety of tissues, the clinical course of which may promote acne, early menarche, certain epithelial cell carcinomas, increased stature, myopia, cutaneous papillomas (skin tags), acanthosis nigricans, polycystic ovary syndrome (PCOS) and male vertex balding. Consequently, these illnesses and conditions may, in part, have hyperinsulinemia at their root cause and therefore should be classified among the diseases of Syndrome X.

Dermatologic conditions associated with diabetes

The development of skin manifestations of diabetes affects up to two thirds of patients with both types 1 and 2 diabetes mellitus. Cutaneous manifestations of diabetes occur because of the microvascular complications of diabetes, impaired wound healing, and other yet undetermined mechanisms. This article summarizes the most frequent skin findings in patients with diabetes, and proposes treatment of some complications.