“Begin with the hands.” Nicotine staining denotes use of cigarettes. Pallor may indicate anaemia as the cause of dyspnoea. Peripheral cyanosis, the presence of a bluish discolouration of the fingers or hands, is due to a high percentage of deoxyhaemoglobin. It is not a reliable sign as it depends upon not only adequate saturation of Hb during transit through the lung but also adequate perfusion of the peripheries.
Clubbing can be associated with many respiratory diseases including cystic fibrosis, bronchiectasis, bronchogenic carcinoma or idiopathic pulmonary fibrosis. Early stages of clubbing may be subtle. The profile angle and phalangeal depth ratio can be used as quantitative indices to assist in identifying clubbing2 (see figure 1.). These values rarely exceed 180° and 1.05 respectively in normal subjects.