What is pallor?
Pallor can be described in the following way:
Pallor (paleness) is the waxy appearance of skin and mucous membrane (normally,
they are pink-coloured). It depends on thickness and quality of skin, and quality
and amount of blood in the capillaries. A person with low haemoglobin or reduced
RBC always looks pale. Anaemia is a pathological condition while pallor is a clinical
entity. Pallor and anaemia are not interchangeable terms; there are many causes of
pallor, and anaemia is commonest of them.
For example, a person looking severely pale may not be anaemic (e.g., Sheehan’s
syndrome).
Pallor of mucous membrane is commonly due to anaemia. It is very difficult to
detect pallor in thick-skinned persons.
Palmar creases become pale when Hb level goes below 7 g/dL. ‘Facial pallor’ is
commonly seen in shock and low cardiac output states (e.g., left ventricular failure
or LVF).
Pallor may be:
– Temporary: Fright, shock (due to vasoconstriction), emotional outburst,
haemorrhage.
– Permanent: Anaemia due to any aetiology, oedematous part of body or myxoedema.
False pallor is due to anasarca (generalised oedema) or myxoedema.
Pallor is a better term than anaemia while doing general survey.
The opposite term for pallor is plethora (ruddy ‘weather-beaten’ appearance).