Pallor

An abnormal generalized or localized cutaneous paleness, resulting from reduced oxyhemoglobin in superficial blood vessels, decreased skin perfusion, or reduced hemoglobin concentration.

Causes

• Hematologic causes

  • Iron deficiency anemia

  • Vitamin B₁₂ deficiency

  • Folate deficiency

  • Acute or chronic hemorrhage

  • Sickle cell anemia

  • Thalassemia

  • Aplastic anemia

  • Hemolytic anemia

  • Leukemia

• Shock: Hypovolemic, cardiogenic, septic, anaphylactic

• Peripheral vascular causes

  • Peripheral vasoconstriction

  • Raynaud phenomenon

  • Peripheral arterial disease

  • Acute arterial occlusion

  • Arterial insufficiency

• Metabolic and endocrine causes

  • Hypoglycemia

  • Hypothyroidism

  • Adrenal insufficiency (less commonly)

• Renal and systemic causes

  • Chronic kidney disease

  • Chronic infection

  • Malignancy

  • Cachexia

• Physiological and environmental causes

  • Stress

  • Fear

  • Anxiety

  • Exposure to extreme cold

  • Frostbite

  • Vasovagal reaction

• Congenital hypopigmentation disorders (localized apparent pallor)

• Medication-induced vasoconstriction