Vascular and lymphatic diseases

Blood vessel disorders

Erythema

Erythema is redness of the skin, usually due to vasodilatation (Table 1). It may be localized, e.g. with pregnancy or liver disease (on palms), fixed drug eruption and infection (e.g. Lyme disease), or generalized, as with drug eruption, toxic erythema (e.g. viral exanthem) and connective tissue disease.

Table 1 Classification of blood vessel and lymphatic disorders

Vessel	Process	Resulting lesion
Small blood vessels	Dilatation (and/or increased flow) Release of extracellular fluid Release of blood Reduced flow Inflammation damage	Erythema, flushing, telangiectasia Urticaria (p. 76), oedema Purpura, capillaritis Livedo reticularis, chilblains, Raynaud’s phenomenon Vasculitis, erythema ab igne
Arteries	Atherosclerosis, Buerger’s disease Inflammation	Ischaemia and ulceration Vasculitis (p. 82)
Veins	Inflammation, flow reduction, clotting abnormalities Dilatation	Thrombosis, skin changes, ulceration (p. 72) Venous lake
Lymphatics	Congenital hypoplasia Blockage or inflammation Infection	Lymphoedema (primary) Lymphoedema (secondary) Lymphangitis