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Diabetic Dermopathy – An Overview

“The chronic complications of diabetes are divided into two types, vascular and non-vascular. The vascular complications could be microvascular (retinopathy, neuropathy, and nephropathy) and macrovascular (coronary artery disease, peripheral artery disease, and cerebrovascular disease). Non vascular complications include infection and skin and joint lesions, as well. Many of the patients with type 2 diabetes have some of these complications at diagnosis because type 2 diabetes is characterized by a long, asymptomatic period. As hyperglycemia persists, chronic complications of diabetes frequently observed since the second decade of hyperglycemia increase. Microvascular complications of type 1 and type 2 diabetes are usually developed because of chronic hyperglycemia and therefore prevention of chronic hyperglycemia helps to prevent and/or delay the incidence of retinopathy, neuropathy, and nephropathy. The role of hyperglycemia in development of macrovascular is less obvious but dyslipidemia and hypertension contribute significantly to incidence of macrovascular complications.”1

This is a benign condition of the skin suffered as a result of diabetes. Unfortunately, the precise cause is idiopathic. However, it is correlated to diabetic neuropathy and diabetes-induced damage of the vascular system. Recent research has shown to back up this claim as they were able to show the frequency of dermopathy increases with the presence of pertinent complications, that is to say, diabetic retinopathy, diabetic nephropathy and diabetic neuropathy.

“Diabetic dermopathy (DD) is a common – however, poorly understood – entity seen as well-demarcated, hyperpigmented, atrophic depressions, macules or papules located on the anterior surface of the lower legs of diabetic patients. In the early 1960s, the Swedish physician Hans Melin studied and characterized a ‘‘circumscribed brownish skin lesion’’ on the lower extremities of patients with diabetes. In 1965, Binkley coined the term ‘diabetic dermopathy’, reflecting his concept that DD is a cutaneous manifestation of diabetic microangiopathy. The entity is also commonly referred to as ‘‘pigmented pretibial patches’’. The incidence of DD ranges 9–55%. Although DD has been reported in patients without diabetes, this has been contested as not an accurate depiction of the case. Though authors have long claimed that the features are non-specific, others have described atrophy of rete ridges, variable pigmentation of basal cells, intimal thickening of superficial blood vessels, medial hypertrophy and hyalinization of deeper arterioles, extravasated erythrocytes, hemosiderin deposition and a mild lymphocytic infiltrate. There have been some studies that implicate a disturbance in blood flow of the skin as the cause of this lesion. Though we have noted melanin deposition in the dermis in the rare case we have encountered in our dermatopathology practice, there have not been any previous description of this. It seems likely that the hemosiderin and ⁄or melanin we have noted histopathologically can account for the pigmented clinical appearance of these lesions.”2

 

Pretibial pigmented - purple macule characteristic of diabetic dermopathy
Pretibial pigmented – purple macule characteristic of diabetic dermopathy

 

The tendency of dermopathy is to appear in the elderly age group as well as those that have suffered from diabetes for ten to twenty years. Badly managed blood glucose levels is indicated by the presence of glycosylated hemoglobin and is said to have a connection to diabetic dermopathy.

“Diabetic dermopathy is more common in patients older than 50 years and in those with a longer duration of diabetes. In older patients diabetic dermopathy was found to occur after a shorter duration of diabetes, whereas in younger patients lesions occurred only after ten years in patients less than 20 years of age. The lesions have been reported to occur more frequently in male patients, however, this difference is not always significant and other studies have not found any difference. It is uncertain as to whether diabetic dermopathy is more common in patients with type 1 or type 2 diabetes.”3

The lesion sites tend to be around areas of low adipose tissue, thin skin near bone structures such as the tibiae portion of the lower limb (shin); dermopathy may also be a heightened symptom of injury suffered in these parts.

“In this study, the mean age of the patients was 60.2 ± 8.83 years and there was a significant association between incidence of diabetic dermopathy and age. In other studies, diabetic dermopathy has been reported most prevalent in 45- to 70-year-old patients and significantly associated with age, as well. Further, the mean duration of diabetes was 9.16 ± 5.42 years and the number of dermopathy lesions was significantly associated with the duration of illness, which is in agreement with other studies. This consistency of the findings further confirms the association between diabetes duration and the number of dermopathy lesions. In addition, mean HbA1c level in the present study was 7.29 ± 1.24 which was significantly associated with the number of dermopathy lesions. This finding confirms other studies’ findings on the association of HbA1c with diabetic dermopathy. Another finding in this study was the significant association between diabetic dermopathy and insulin intake, which is in line with a study reporting a significantly lower incidence of dermopathy in the patients under treatment with insulin than those taking oral medications.”4

Signs

The typical way in which dermopathy lesions appear is a patchy skin that can appear to be pinkish, tanned, dark brown or red in color is appears most prominently on and around the shin area. Other areas in which these lesions appear are the thighs, the lateral portions of our feet and forearms, trunk and scalp. The texture of these lesions can also be flaky or scale-like in nature and have a regular oval or sometimes round shape. Surprisingly, itchiness and burning are a rare occurrence in dermopathy.

“The lesions are asymptomatic and there are only a few reports of their onset and progression. The lesions begin spontaneously as non-blanching, scaly, red or purple, round or oval macules or papules. There may be induration, with a central depression or vesiculation. These lesions subsequently progress to the characteristic scar-like lesions of diabetic dermopathy. In established lesions there may be a thin keratin scale. Most frequently presenting as round, brown, atrophic lesions of less than 1 cm diameter, some may be elongated and up to 2.5 cm. They usually occur on the shins in a bilateral asymmetrical distribution, but have been rarely reported on the arms, thighs, trunk and abdomen. The intensity of pigmentation corresponds to the degree of atrophy, with the darkest lesions also being the most atrophic. Each individual lesion lasts on average 18-24 months, before fading to minimally atrophic macules, or clearing completely. In some cases, the brownish colour disappears and is replaced by a slight depigmentation. As older lesions clear, new lesions appear.”5

Another interesting fact is that the appearance of four or more lesions only occurs in diabetic patients, while not in non-diabetic persons, further supporting the leading belief among medical professionals and researchers that dermopathy is correlated to angiopathic complications of diabetes. Therefore, it is recommended to be tested for diabetes as soon as a shin lesion appears so that diagnosis could provide the answer on what steps to take next.

“The differential diagnosis of DD (Diabetic dermopathy) includes many diseases. Early lesions of DD (Diabetic dermopathy) can be mistaken with fungal infection. While typical brownish atrophic scars may require differentiation of Schamberg’s disease (progressive pigmented purpuric dermatitis), purpura annularis telangiectasica, purpuric lichenoid dermatitis, pigmented stasis dermatitis, scarring lesions, papulonecrotic tuberculids, factitious dermatitis and abrasions. Many of these entities can be differentiated by distribution, appearance and natural history.”6

“The origin of DD (Diabetic dermopathy) is unknown and there is no relation with decreased local perfusion. Another possible explanation is due to mild traumas that do not compromise wound healing. There is also degeneration of subcutaneous nerves in patients with neuropathy. However, the most acceptable explanation is the relation between DD and microvascular complications of diabetes. Studies have shown strong association with DD, nephropathy, retinopathy or neuropathy.”7

“Diabetic dermopathy probably represents post-traumatic atrophy and postinflammatory hyperpigmentation in poorly vascularized skin. Recent report showed that most patients have an increase in glycosylated hemoglobin and a long history of diabetes.”8 

As with most complications and ailments that result from suffering from diabetes, the immediate recommendation for treatment is proper management of glucose levels. If glucose is not properly managed, exacerbation of the lesions of dermopathy is imminent and the scaly part of the lesion can indent inwards, eventually exposing deep tissue.

Dermopathy is then, considered a marker that indicates to a person with these lesions that they should be tested in order to rule out diabetes and begin a strategy for glucose level management. It also seems that there is no significant difference in the incidence of dermopathy between type 1 and type 2 diabetes.

“The lesions of diabetic dermopathy are asymptomatic and no treatment is recommended or has been shown to be effective. Cosmetic camouflage may be used to disguise the appearance of the skin lesions if required. However, given the strong association of diabetic dermopathy with other microangiopathic complications of diabetes, the lesions might be considered a surrogate for more serious pathology. The finding of skin lesions with the appearance of diabetic dermopathy in patients not previously known to have diabetes should prompt investigations for the condition. Given the association with other microvascular complications, optimization of glycemic control in patients with diabetic dermopathy to minimize the progression of retinopathy, nephropathy and neuropathy is paramount.”9  

 “From the above observations it is clear that skin is involved in diabetics quite often and earlier than general population. 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. Whereas if any obese patient presents with multiple shin spots having fasting blood glucose levels towards the higher side of normal along with the a positive family history of diabetes mellitus should undergo further investigation to rule out the possibility of early diabetes and other microangiopathies as recognition of this finding is the key to early diagnosis and prevention of chronic disease like diabetes and microangiopathies.”10 

 

References:

(1, 5) A study on the association of diabetic dermopathy with nephropathy and retinopathy in patients with type 2 diabetes mellitus. Mirhoseini, M., Saleh,  N., Momeni, A., Deris, F. & Asadi-Samani, M. Journal of Nephropathology. 2016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5125061/

(2) Defining diabetic dermopathy. McCash, S. & Emanuel, P.O.The Journal of Dermatology. 2011. https://www.researchgate.net/publication/51495686_Defining_diabetic_dermopathy

(3, 5, 9) Diabetic dermopathy. McGeorge, S. & Walton, S. The British Journal of Diabetes and Vascular Disease. 2014. https://bjd-abcd.com/index.php/bjd/article/viewFile/24/63

(6, 7) Diabetes mellitus and the skin. Mendes, A.L., Miot, H.A. & Haddad Junior, H. Anais Brasileiros de Dermatologia. 2017. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0365-05962017000100008&lng=en&tlng=en

(8, 10) Incidence of diabetic dermopathy. Kalsy, J., Malhotra, S.K. & Malhotra, S. Journal of Pakistan Association of Dermatologists. 2012. http://applications.emro.who.int/imemrf/J_Pak_Assoc_Dermatol/J_Pak_Assoc_Dermatol_2012_22_4_331_335.pdf

 

María Laura Márquez
13 October, 2018

Written by

María Laura Márquez, general doctor graduated from The University of Oriente in 2018, Venezuela. My interests in the world of medicine and science, is focused on surgery and its greatest advances. Nowadays I practice my...read more:

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