Skin And Systemic Disease

Question 1

What can skin changes be a sign of?

Answer 1

• endocrine disease (eg. Diabetes, thyroid, Cushings etc.)
• internal malignancy
• nutritional deficiency
• systemic infection
• systemic inflammatory disease

Question 2

What skin changes are associated with thyroid insufficiency?

Answer 2

• dry skin (hypothyroidism)
• pretibial myxedema: puffy, swollen, velvet-texture with exaggerated skin markings (graves - hyperthyroidism)
• thyroid acropachy (Graves): soft tissue swelling of distal digits and around nail causing bowing/curvature of the nail

Question 3

What skin changes are associated with diabetes?

Answer 3

• necrobiosis lipoidica: red and yellow waxy plaques which can split, break and ulcerate, affects shins bilaterally
• diabetic dermopathy: vague inflammatory papules/patches, itch with hyperpigmentation affecting lower limbs
• sclerederma: woody inflammatory infiltrate which is warm to touch, reduction in elasticity so skin cannot be pinched, usually in upper back
• leg ulcers: common over pressure points
• granuloma annulare: circular plaques raised on surface of skin (pockets of histiocytes forming inflammatory margins on histology), tend to be on hands and feet

Question 4

Describe the skin changes associated with steroid levels in the body

Answer 4

• steroid excess (eg. Cushings): acne, striae, erythema, gynaecomastia
• steroid insufficiency (eg. Addisons): hyperpigmentation (esp on mucosal surfaces inside of the mouth), acanthosis nigracans

Question 5

Describe the skin changes associated with sex hormone levels in the body

Answer 5

• high testosterone (in PCOS, testicular tumours, exogenous testosterone in drug therapy): acne, hirsutism
• high progesterone (in congenital adrenal hyperplasia, contraceptive treatment): acne, dermatitis

Question 6

Describe skin changes associated with internal malignancy

Answer 6

• necrolytic migratory erythema/glucognoma syndrome (rare): distinctive scaly red plaques on actral, interiginous and periorifical areas (islet cell tumour of pancreas)
• erythema gyratum repens (rare): red concentric bands whorled pattern with severe itch and raised eosinophil count (lung cancer)
• acanthosis nigricans (sometimes cancer): hyperpigmented velvet-like hyperkeratotic plques in folds of the skin = type 1 associated with adenocarcinoma of GIT
• erythema annulare = red circles
• Sweet’s Syndrome: affects neck and head, redness and ulceration (haematological cancer)
• Sister Mary Joseph nodule (urinary cancer)

Question 7

Describe the skin changes associated with nutritional deficiency

Answer 7

• vitamin B: B6/pyridoxine = dermatitis, B12/cobalamin = angular chelitis, B3/niacin = dementia, diarrhoea, dermatitis
• zinc: acrodermatitis enteropathica, blistering and pustules with redness and inflammation
• vitamin C (scurvy): punctate purpura/bruise that is non-blanching, corkscrew spiral hairs on arms and legs, patchy hyperpigmentation, dry skin and hair, non-healing wounds and inflamed gums

Question 8

What are the causes of zinc deficiency?

Answer 8

• inherited mutation to intestinal zinc transporter
• infants: low levels in breast milk
• adults: reduced intake due to alcoholism, malabsorption, IBD, bowel surgery

Question 9

What is erythema nodosum and its causes

Answer 9

• dermal bruise of shins/lower legs with discolourisation with red/purple changes on skin surface, really uncomfortable so can’t have anything touching it
• causes: strep infection, pregnancy, OC, sarcoidosis, drugs, bacterial/viral infection

Question 10

What is pyoderma gangrenosum and its causes?

Answer 10

• deep ulcer over shin/lower leg, with purple overhanging edge
• causes: IBD (Crohns/UC), RA, myeloma, others

Question 11

Describe skin changes associated with hair and nails

Answer 11

• autoimmune = alopecia areata hair loss (distinct bald areas, well-defined)
• hair loss (B12, iron deficiency, lupus, hypothyroidism)
• male pattern balding (androgen excess)
• nail clubbing (lung malignancy), nail fold telengectasia (connective tissue disorders)