Thomboangiitis Obliterans (TAO)
Inflammatory nonatherosclerotic occlusive changes in distal arteries and veins. More common in Middle, Near and Far East.
Unknown cause – may involve a hypersensitivity to cigarettes. Higher incidence of HLA-A9 & HLA-B5.
Usually males aged 20-40 who smoke – usually heavy smokers (may be a hypersensitivity to smoking).
Pathologically, it is a vasculitis of small and medium sized vessels. Tobacco plays a central role in initiation and pathogenesis.
Usually starts in most distal vessels, them progresses proximally; similar clinical features to arterial insufficiency with claudication (ie rest pain, cyanosis, cold); recurrent/episodic superficial migratory thrombophlebitis; Raynauds phenomenon (in 10%); always bilateral – but may have some asymmetry – up to 40% may involve 3+ limbs; claudication in arch is characteristic in 25% (often misdiagnosed); may present with extremely painful toes – or digital ulcers/gangrene.
Significant case of amputation in younger patients.
Cessation of smoking is essential to halt progression.
Local treatment of ischaemic lesion(s)