Pallor

Pallor is the paleness of the skin and mucous membranes caused by reduced hemoglobin concentration, reduced red blood cell mass, or decreased cutaneous perfusion. It is a clinical sign rather than a diagnosis, and its prominence varies with lighting and skin pigmentation. Conjunctival pallor is often more reliable than facial pallor in individuals with darker skin tones.

Causes include decreased red cell mass from anemia (iron deficiency, megaloblastic anemia, aplastic anemia, hemolytic anemias) and acute blood loss, as well as reduced perfusion from shock, vasoconstriction, or cold exposure. It may also occur physiologically in infancy or during pregnancy and in chronic illnesses.

Evaluation relies on history and examination. Symptoms such as fatigue, dyspnea, tachycardia, and orthostatic lightheadedness support clinically significant anemia. Physical findings include conjunctival pallor, pallor of the nail beds, and generalized pallor.

Laboratory assessment typically includes a complete blood count to determine anemia, reticulocyte count, and iron studies (serum ferritin, iron, total iron-binding capacity). If anemia is detected, further testing for vitamin B12 and folate deficiency, hemolysis, or marrow disorders may be indicated.

Management targets the underlying cause. Iron deficiency is treated with oral or intravenous iron; other anemias require disease-specific therapy. Severe pallor with symptomatic anemia or active bleeding may necessitate red blood cell transfusion. In patients with hypoperfusion or shock, stabilization and fluid resuscitation are priorities.

Prognosis depends on the underlying condition and the response to treatment. Pallor itself typically improves as anemia or perfusion is corrected.

See also: anemia, iron-deficiency anemia, cyanosis.