Page created on February 9, 2022. Not updated since.
Evaluation of pallor
Pallor refers to paleness of the skin. It becomes apparent on the conjunctiva before it becomes apparent on the skin. Pallor occurs when the haemoglobin concentration is decreased (anaemia) or blood is distributed away from the skin. Conjunctival pallor often presents when the Hb <100 g/L, while skin pallor presents at Hb <80 – 90 g/L. The palmar creases lose their red colour when Hb <70 g/L.
The first priority is to determine whether the cause of pallor is life-threatening. Look for signs of severe haemorrhage like tachycardia, dehydration, or shock, and signs of severe haemolysis, like jaundice or dark urine.
History is important to determine whether the onset is acute or chronic, and whether there are any risk factors for nutrient deficiency anaemia or hereditary anaemia. CBC with differential and reticulocyte count are obligatory, as the most likely causes can be suspected based on this. POCT glucose can rule out hypoglycaemia.
Differential diagnosis
| Etiology | Typical features |
| Iron deficiency anaemia | Low-iron diet, menstruating adolescent, pica |
| Haemolytic anaemias | Jaundice, hepatomegaly, family history |
| Haemorrhage | Trauma, signs of dehydration |
| Shock | Cool skin, prolonged CRT, hypotension |
| Acute leukaemia | Malaise, infections, skin bleeding, lymphadenopathy |
| Hypoglycaemia | Sweating, irritability, headache |
| Neuroblastoma | Abdominal mass, weight loss |
| Infective endocarditis | Fever, ill child, embolic phenomena, new murmur |