Dermatology

• Diabetes mellitus is one of the major global health problems because of its increasing prevalence and the complexity of its systemic and local manifestations
• Diabetes affects more than half a billion of the world's population today and it is present in more than 10.5% of the adult population
• The dermatologist has a very important role in detecting the associations between diabetes and skin manifestations
• Diabetes mellitus

  A metabolic disorder of diverse etiology characterized by chronic hyperglycemia with disturbances in the protein, carbohydrate and fat metabolism resulting from impaired insulin action, insulin secretion or both
• Between 30% and 70% of the patients with DM (both type 1 and type 2) will develop a skin complication at some point in the course of the disease
• Skin manifestations of diabetes

  • They have a varied impact on health ranging from cosmetic changes to life-threatening manifestations
• Acanthosis nigricans

  A common manifestation in diabetes mellitus, more common in type 2, characterized by dark brown or grey plaques and a thickened, warty surface predominantly arranged in folds and usually asymptomatic
• Acanthosis nigricans can also occur in other endocrinopathies associated with insulin resistance and in some malignancies not correlated with diabetes
• Pathogenesis of acanthosis nigricans

  Activation of the insulin-like growth factor-1 (IGF-1) receptors in the keratinocytes and the fibroblasts, leading to cell proliferation, induced by hyperinsulinemia
• Treatment of acanthosis nigricans

  1. General measures like weight loss, physical activity, proper diet

  2. Glycemic control through oral antidiabetics

  3. Oral retinoids or topical keratolytic agents for fissures or hyperkeratotic areas
• Diabetic dermopathy "shin spots"


  The most common manifestation of diabetes (50% of patients), appearing as multiple small red papules that heal slowly leaving an atrophic brownish scars, occurring mainly on the shins, thigh and forearms, mostly in the young adult males
• Erysipelas-like erythema

  A well demarcated red areas on the legs or feet of the elderly diabetics
• Diabetic rubeosis

  A rosy reddening of the face and sometimes affects the hands and feet
• Atherosclerosis

  Frequent in diabetes due to the large vessel disease
• Wet gangrene of the foot

  A late manifestation of the microangiopathy in diabetes
• Distal symmetrical motor and sensory polyneuropathy

  Leading to painless slowly penetrating ulcers of the soles which may be induced or exacerbated also by associated atherosclerosis or infection
• Autonomic neuropathy

  May occur in diabetes, presented as impotence, functional diarrhea and decreased or absent sweating of the lower extremities
• Cutaneous infections in diabetes

  More frequent, including Staphylococcus aureus leading to repeated boils, non-clostridial gangrene, and candidiasis of the mouth, genitalia, nails and intertriginous areas
• Diabetic bullae

  Common in Iraqi patients, appearing as non-traumatic non-inflammatory bullae mostly on the feet and hands, healing even without treatment in 4-6 weeks without scarring
• Pruritus

  Specially in the localized areas like pruritus vulvae due to secondary candidiasis or may be generalized pruritus due to the dry skin
• Necrobiosis lipoidica

  A rare granulomatous dermatological condition occurring in 0.3% of diabetic patients, predominantly in females with type 1 diabetes, characterized by round erythematous papules converging into plaques with purplish-red margins and an atrophic, sclerosing, yellow-brown center with telangiectasias, often asymptomatic but may present with itching, hypoesthesia or pain if ulceration occurs
• Treatment of necrobiosis lipoidica

  1. Topical, intralesional or systemic corticosteroids in the active phase

  2. Systemic aspirin and dipyridamole

  3. Nicotinamide

  4. Ticlopidine as antiplatelet

  5. Preilesional heparin injection

  6. Other options: calcineurin inhibitors, pentoxifylline, TNF-alpha inhibitors, synthetic antimalarials and PUVA

  7. For ulcerated and superinfected lesions: local antibiotics, emollients, compressive bandaging
• Acromegaly

  A disorder due to increased growth hormone secretion, characterized by oily and wet skin with hyperhidrosis, thickened lower lip, large and furrowed tongue, increased skin pigmentation, hirsutism and fine, silky and sparse scalp hair, flat and wide nails growing fast
• Hypopituitarism (Sheehan's Syndrome)

  Characterized by pallor of the skin with yellowish tinge, generalized hypopigmentation, increased sensitivity to sunlight and diffuse hair loss especially in the axillae and pubic areas
• Cushing Syndrome

  Characterized by fat deposition over the clavicles & back of the neck, puffy, rounded erythematous face with telangiectasia, truncal obesity with slender wasting limbs, striae distensae, hirsutism, acne, androgenic alopecia, Addisonian-like pigmentation, and easy bruising
• Striae distensae

  Irregular lines that may be several centimeters in length with variable width, appearing slightly elevated, plethoric and irritable in the acute stage and then gradually flattened and the color fading over months and years, occurring mainly in the lumbosacral and anterior aspect of the thigh in males and on the buttocks, thighs and breasts in females
• Causes of striae distensae

  • Idiopathic, especially in adolescents and at puberty, or in those who gain weight suddenly
  • Pregnancy
  • Endocrine disorders like Cushing Syndrome
  • Iatrogenic from systemic or potent topical steroids, anabolic drugs or androgens
• There is no effective treatment for striae distensae, just explanation and reassurance
• Addison's Disease (Hypocorticism)

  Characterized by generalized hyperpigmentation more prominent on light exposed areas, scars, genitalia, palmar and finger creases and under the nails, including mucous membranes, and loss of pubic and axillary hair in females
• Hyperthyroidism


  Characterized by red, soft, moist and hot skin, Addisonian hyperpigmentation, diffuse thinning of scalp hair, rapid nail growth and distal onycholysis, generalized pruritus and urticaria, palmar erythema and facial flushing, hyperhidrosis, and pretibial myxedema
• Generalized hyperpigmentation

  More prominent on light exposed areas, scars, genitalia, palmar and finger creases, and under the nails. Affects the mucous membranes.
• Addison's Disease (Hypocorticism)

  • Loss of pubic and axillary hair in females
  • Improvement of acne
• Hyperthyroidism

  • Red, soft, moist and hot skin
  • Addisonian hyperpigmentation (not affecting mucous membranes)
  • Diffuse thinning of scalp hair
  • Rapid nail growth and distal onycholysis (Plummer's nails)
  • Generalized pruritus and urticaria
  • Palmar erythema and facial flushing
  • Hyperhidrosis or increased sweating
  • Pretibial myxedema
  • Thyroid acropatchy
• Hypothyroidism

  • Puffy face with coarse features
  • Pale, thickened, cold, finely scaling and wrinkled skin
  • Coarse sparse scalp hair with loss of lateral third of eyebrows
  • Brittle and striated nails
  • Poor wound healing
  • Decreased or absent sweating
• Crohn's Disease (Regional Ileitis)


  • Perianal abscess and fistulae
  • Erythema nodosum
  • Erythema multiforme
  • Aphthous-like stomatitis and glossitis
  • Cutaneous vasculitis
  • Epidermolysis bullosa acquisita
  • Metastatic Crohn's disease as cutaneous granulomas
  • Pyoderma gangrenosum
• Pyoderma Gangrenosum

  Destructive necrotizing non-infectious ulcer of the skin, starting as small furuncle, pustule or hemorrhagic bullae that rapidly ruptures forming an expanding and painful ulcer. Dusky red or violaceous and undermined edge. Purulent base.
• Causes of Pyoderma Gangrenosum

  • Idiopathic (50%)
  • Inflammatory bowel disease (Crohn's, ulcerative colitis)
  • Connective tissue diseases (rheumatoid arthritis, SLE, Behcet's)
  • Blood diseases (leukemia, multiple myeloma, polycythemia, monoclonal gammopathy)
• Treatment of Pyoderma Gangrenosum

  • Dealing with underlying cause
  • Systemic steroids in high dose (60-80mg oral prednisolone daily, then reduced gradually)
  • Azathioprine, dapsone, or cyclosporine may be needed
• Ulcerative Colitis

  • Skin lesions identical to Crohn's disease, but pyoderma gangrenosum, oral ulcers and erythema nodosum are more common
• Non-specific features of malabsorption

  • Pallor
  • Dry skin
  • Edema
  • Acquired ichthyosis
  • Pigmentary disorders
  • Glossitis
  • Mouth ulcers