Heat signatures of a<unk> 's hand (top) and a healthy hand (bottom): Red indicates warm areas whilst green indicates cool areas. (Image taken with a thermographic camera) Consensus diagnostic criteria Distinguishing<unk> 's disease (primary<unk> 's) from<unk> 's phenomenon (secondary<unk> 's) is important. Looking for signs of arthritis or vasculitis, as well as a number of laboratory tests, may separate them. Nail fold capillary examination or "capillaroscopy" is one of the most sensitive methods to diagnose<unk>  with connective tissue disorders, ie distinguish a secondary from a primary form objectively. If suspected to be secondary to systemic sclerosis, one tool which may help aid in the prediction of systemic sclerosis is thermography. A careful medical history will seek to identify or exclude possible secondary causes. * Digital artery pressures are measured in the arteries of the fingers before and after the hands have been cooled. A decrease of at least 15 mmHg is diagnostic (positive). * Doppler ultrasound to assess blood flow * Full blood count may reveal a normocytic anaemia suggesting the anaemia of chronic disease or kidney failure. * Blood test for urea and electrolytes may reveal kidney impairment. * Thyroid function tests may reveal hypothyroidism. * Tests for rheumatoid factor, erythrocyte sedimentation rate, C-reactive protein, and autoantibody screening may reveal specific causative illnesses or an inflammatory process. Anti-centromere antibodies are common in limited systemic sclerosis (CREST<unk> . * Nail fold vasculature (capillaroscopy) can be examined under a microscope. To aid in the diagnosis of<unk> 's phenomenon, multiple sets of diagnostic criteria have been proposed. Table 1 below provides a summary of these various diagnostic criteria. Recently, International Consensus Criteria were developed for the diagnosis of primary<unk> 's phenomenon by a panel of experts in the fields of rheumatology and dermatology.
Raynaud syndrome
Patterson syndrome
Popliteal artery entrapment syndrome
Fountain syndrome
Burning feet syndrome
Popliteal artery aneurysm
Neurogenic claudication
Diabetic foot