Skin Signs In Systemic Disease Flashcards
Skin manifestations of tuberous sclerosis
Angiofibromas,
peri-ungual fibromas,
Shagreen patches,
ash leaf white macules
Skin manifestations of neurofibromatosis
Neurofibromas,
cafe au lait macules,
axillary freckling,
Lisch nodules
Name 3 cutaneous infections that diabetic patients have an increased risk of
Erysipelas
Candidiasis (hyperglycaemia favours candidal growth)
Chronic paronychia
Hypertrtriglyceridaemia (e.g. in diabetes) can cause what cutaneous presentation
Xanthomata
Hyperinsulinaemia can cause what cutaneous presentation
Acanthosis Nigricans
What is the name for the cutaneous skin condition that can occur in diabetic patients and presents as raised, red & shiny patches with a yellow center
Necrobiosis lipodica
Name a cutaneous complication of diabetes
Leg ulcer
Why does the thyroid hormone affect the skin?
Thyroid hormone receptors present in keratinocytes, fibroblasts, arrector pili muscle cells, hair follicle cells, smooth muscle cells, sebaceous gland cells, vascular endothelial cells etc
What effects does the thyroid hormone have on the skin
• Promotes fibroblast activity
• Regulates epidermal differentiation
• Essential for hair formation and sebum production
• Effects on skin perfusion
Name cutaneous features of hyperthyroidism
• Warm, moist smooth skin
• Facial flushing, palmar erythema
• Fine, thin hair. Diffuse alopecia (slower hair turnover time)
• Hyperhidrosis
• 5% - nail changes (concave, distal onycholysis)
• Pruritus
Name cutaneous features of hypothyroidism
• Cold, dry pale skin
• Xerosis – may resemble acquired ichthyosis
• Carotenaemia
• Dry, coarse brittle hair, diffuse alopecia
• Loss of lateral 1/3 eyebrow (madarosis)
• Thickened brittle nails
• Myxoedema (e.g. peri-orbital oedema, facial puffiness)
Name a cutaneous features that is characteristic of Graves’ disease
Pretibial myxoedema
What is the proposed pathophysiology of pretibial myxoedema
Fibroblasts stimulated by autoantibodies to produce high amounts of glycosaminoglycans which accumulates in the dermis
Why can hypothyroidism cause carotenaemia (yellow/orange skin that spares the eyes)
conversion of beta-carotene (provitamin A) to vitamin A (retinol) is accelerated by thyroxine.
Why does hypothyroidism cause myxoedema
dermal accumulation of mucopolysaccharides – mainly hylauronic acid
Name a cutaneous features of Addison’s disease
•Diffuse hyperpigmentation
•Palmar crease pigmentation
•Buccal pigmentation
Why does Addison’s cause hyperpigmentation
Absence of normal feedback to pituitary leads to increased ACTH + MSH production leading to increased melanogenesis (common pre-cursor – pro-opiomelanocortin)
What cutaneous features can occur as a result of an endocrine tumour with androgenic activity
Virilisation
Hirsutism
Acne
Baldness
Cutaneous / Chronic Discoid LE (CDLE) cutaneous features
• Photosensitivity
• Erythematous indurated plaques on exposed sites
• Follicular plugging
• Heal with scarring / permanent alopecia
Cutaneous / Chronic Discoid LE (CDLE) diagnosis
Biopsy with immunofluorescence
Cutaneous / Chronic Discoid LE (CDLE) treatment
- sun avoidance
- potent steroids
- hydroxychloroquine
Subacute cutaneous LE cutaneous features
- Annular erythematous scaly plaques, not indurated.
- Symmetrical rash with no plugging or scarring
- Photosensitivity
Where does subacute cutaneous LE cutaneous features typically occur
On sun-exposed sites, esp upper back / shoulders / arms
Are autoantibodies present in CDLE or SCLE
CDLE may be ANA positive
SCLE may be ANA or Ro or La positive
Subacute cutaneous LE cutaneous diagnosis & treatment
Same as DCLE
Systemic LE (SLE) cutaneous features
- Butterfly, ‘malar’ rash in 50%
- Photosensitivity
- Prominent capillaries in nail fold
- May have CDLE type rash
Dermatomyositis cutaneous features
•Photosensitivity rash like that of L.E.
•Heliotrope oedema of eyelids
•Linear finger rash with Gottron’s papules
Systemic sclerosis vs scleroderma
Scleroderma is the skin changes of systemic sclerosis
Systemic sclerosis two types
•Diffuse cutaneous
•Limited cutaneous (aka CREST)
Systemic sclerosis cutaneous features (scleroderma)
•Pinched mouth – radial furrows
•Beaked nose
•Matt - like facial telangectasia
•Sclerodactyly
•Periungual telangiectasia / ragged cuticles
•Raynaud’s phenomenon in 85%
•(Dysphagia)
Describe erythema multiforme
Typically “Target” or “Iris” lesions
Where does erythema multiforme usually occur on the body
Knees, Elbows, Palms, Soles and Mucosae
Erythema multiforme minor vs Major
•Minor – skin only
•Major – skin + mucosal involvement
Erythema multiforme aetiology
- Viral - HSV
- Bacterial - TB, Strep, Mycoplasma
- Other e.g. drugs (Sulphonamide), autoimmune, malignant
Describe erythema nodosum
Red, tender, diffuse nodules that may be assoc. with joint pains & fever. Typically occurs on the shins
Erythema nodosum aetiology
•Infections – Strep, TB, EB, fungal
•Drugs – OCP, sulphonamides
•Autoimmune - Inflammatory bowel disease
•Sarcoidosis
Describe cutaneous vasculitis
Non-blanching, purpuric rash ± bullae and necrosis.
Where does cutaneous vasculitis typically affect on the body
Lower legs
Cutaneous vasculitis aetiology
Many causes (vasculitis screen)
–Drugs
–Infective
–Autoimmune
–Neoplastic
Describe livedo reticularis & state when it is exacerbated
Mottled cyanotic network exacerbated by cold
Livedo reticularis aetiology
–Cardiac failure
–Vascular emboli
–Drugs
–Throbocythaemia
–Cryoglobulins
–Arteritis (PAN, SLE, RA, DM, lymphoma)
–Infections
What is Mycosis Fungoides
Primary cutaneous T cell lymphoma
Describe the presentation of Mycosis Fungoides
1st stage - patch (rash) stage
2nd stage - plaque stage
3rd stage - tumour stage
What is Paget’s disease of the nipple a sign of
Breast cancer
What is sister Mary Joseph nodule
Aka umbilical metastasis
Is a common site of GI, breast, lung & pelvic metastasis
What would you want to exclude in a patient presenting with acquired ichthyosis
Lymphoma
Acanthosis nigricans aetiology
Hyperinsulinaemia
- Diabetes
- Insulin resistance
- obesity
What is erythema gyratum repens
rare paraneoplastic type of annular erythema with a distinctive figurate ‘wood-grain’ appearance
Name some skin disorders associated with HIV
•Kaposi’s sarcomas – initial presentation in up to 25%.
•Seborrhoeic eczema / folliculitis – seen in at least 50%
•Skin infections – herpes, molluscum, candida, staph. etc
•New onset / worsening psoriasis
•Dry skin / pruritus
Generalised erythroderma aetiology
Skin condition - Psoriasis, dermatitis, ichthyosis, lupus
Drug reaction
Malignancy - cutaneous T-cell lymphoma
What is important about dermatomyositis
It can be associated with an underlying malignancy
