Skin presentation of systemic disease Flashcards
What are some skin manifestations of diabetes?
Small and large vessel angiopathy
Xanthomata
Xanthelasma
Erysepelas (Caused by hyperglycaemia leading to infection)
Necrobiosis lipidoica
Acanthosis nigricans
What is necrobiosis lipidoica?
A granulomatous inflammatory reaction around destroyed collagen, usually found in diabetes
What condition is shown?
Erysipelas
What condition is shown?
Necrobiosis lipidoica
What condition is shown?
Xanthelasma
What condition is shown?
Acanthosis nigricans
What cells contain thyroid hormone receptors in the skin?
Keratinocytes, fibroblasts, arrector pili muscle cells, hair follicle cells, smooth muscle cells, sebaceous gland cells, vascular endothelial cells
What are the effects of thyroid hormone on the skin?
- Promotes fibroblast activity
- Regulates epidermal differentiation
- Essential for hair formation and sebum production
What are some skin presentations of hyperthyroidism?
- Warm, moist smooth skin
- Facial flushing, palmar erythema
- Fine, thin hair. Diffuse alopecia (increased hair turnover time)
- Hyperhidrosis
- 5% - nail changes (concave, distal onycholysis)
- Pruritus
- Graves disease – pretibial myxoedema also present
- Urticaria / angioedema (uncommon – linked to thyroid autoimmunity)
What condition is shown?
Pre-tibial myxoedema - Fibroblasts stimulated by autoantibodies to produce high amounts of GAGs, which accumulates in the dermis
What are some skin presentations of hypothyroidism?
- Cold, dry pale skin
- Xerosis – may resemble acquired ichthyosis
- Carotenaemia - The conversion of beta-carotene (provitamin A) to vitamin A (retinol) is accelerated by thyroxine.
- Dry, coarse brittle hair, diffuse alopecia
- Loss of lateral 1/3 eyebrow (madarosis)
- Thickened brittle nails
- Generalised myxoedema
- Peri-orbital oedema
- Facial puffiness
What causes myxoedema?
Dermal accumulation of mucopolysaccharides, mainly hyaluronic acid, which disappears with correction of T4 level
What are some skin changes in Addison’s disease?
- Diffuse hyperpigmentation
- Palmar crease pigmentation
- Buccal pigmentation
What are some skin presentations of tumours with MSH-like activity (E.g. pituitary tumours)?
Hyperpigmentation
What are some skin presentations of tumours with androgenic activity (E.g. ovarian tumours)?
Virilisation
Hirsutism
Acne
Baldness