1. Skin Disorders of Diabetes Mellitus Pongsakorn Thitachote, MD

2. Introduction Diabetes mellitus is a common condition which frequently has skin manifestations. The attachment of glucose to protein may result in a profound effect on structure and function of that protein, and account for clinical manifestations of the disease

3. Introduction (cont.) It has been suggested that increased crosslinking of collagen in diabetic patients is responsible for the fact that their skin is generally thicker than that of non-diabetics It is suggested that these skin changes may eventually be used as a reflection of the patient's current as well as past metabolic status

4. Diabetic Dermopathy the most common cutaneous finding in diabetes also called shin spots and pigmented pretibial patches characterized by bilateral multiple hyperpigmented macules on the pretibial areas

5. Diabetic Dermopathy (cont.) may also appear on the forearm, the side of the foot, and the anterior surface of the lower thigh round or oval, reddish-brown, scaly papules and plaques, ranging in size from 0.5 cm The lesions eventually evolve into the characteristic shallow pigmented scars typical of diabetic dermopathy

6. Diabetic Dermopathy (cont.) In several studies, shin spots were produced in response to trauma with heat, cold, or blunt objects in persons with diabetes closely linked to abnormal glucose metabolism

10. Necrobiosis Lipoidica Diabeticorum one of the best known cutaneous markers for diabetes initially presents with well-circumscribed erythematous papules, which develop into large, irregularly delineated plaques with a waxy, yellow center

11. Necrobiosis Lipoidica Diabeticorum (cont.) the epidermis becomes thin and transparent, allowing underlying vasculature to become visible The involved peripheral tissue is slightly raised and has a reddish-blue color About 85% of NLD cases occur on the legs bilaterally Lesions can also appear on the face, scalp, hands, forearms, or abdomen

12. Necrobiosis Lipoidica Diabeticorum (cont.)

16. Bullosis Diabeticorum Rare a distinct marker for diabetes usually on the feet and toes, but occasionally on the hands and fingers Bullae are blisters spontaneously appearing from normal skin. They are usually 0.5 to several centimeters in size, and contain a clear, sterile, viscous fluid

17. Bullosis Diabeticorum (cont.) Two major types of bullae, intraepidermal and subepidermal, have been defined Intraepidermal bullae are clear, sterile, nonhemorrhagic blisters that generally heal on their own within two to five weeks without scarring or atrophy. Most patients developing this type of bullae are men between ages 40 and 75 with long-standing diabetes, peripheral neuropathy, and good circulation to the involved extremity

18. Bullosis Diabeticorum (cont.) Subepidermal bullae are the least common of the two types of bullosis diabeticorum. These blisters are similar to the intraepidermal blisters except they occasionally are hemorrhagic and may heal with scarring and atrophy

20. Granuloma Annulare Granuloma annulare is identified by its characteristic annular or arciform plaques that begin as flesh-colored, red, or reddish-brown papules symmetrically spread across the upper trunk, neck, arms, and occasionally the legs

21. Granuloma Annulare (cont.)

24. Acanthosis Nigricans Rough, velvety, dark patches of skin on the back of the neck It is now evident that a close association exists between AN, obesity, and insulin resistance