Differential Diagnosis for Petechiae on Hands

• Single most likely diagnosis
  • Viral infection: Many viral infections, such as hand, foot, and mouth disease or viral gastroenteritis, can cause petechiae on the hands due to the body's immune response and potential vascular damage.
• Other Likely diagnoses
  • Trauma or injury: Physical trauma, such as a blow to the hand or intense gripping, can cause petechiae due to blood vessel rupture.
  • Allergic reactions: Allergic reactions to certain substances, like medications, foods, or insect bites, can lead to petechiae as part of an allergic response.
  • Vitamin deficiencies: Deficiencies in vitamins like C or K can impair blood vessel integrity or blood clotting, leading to petechiae.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Meningococcemia: A severe bacterial infection that can cause petechiae or purpura, which can rapidly progress to sepsis and is life-threatening if not promptly treated.
  • Idiopathic thrombocytopenic purpura (ITP): An autoimmune condition where the body attacks platelets, leading to low platelet counts and increased risk of bleeding, including petechiae.
  • Leukemia: Certain types of leukemia can cause petechiae due to bone marrow suppression affecting platelet production or function.
• Rare diagnoses
  • Vasculitis: Inflammation of the blood vessels, which can cause petechiae among other symptoms, due to various autoimmune or infectious causes.
  • Scurvy: A disease caused by severe vitamin C deficiency, leading to collagen synthesis defects and potentially causing petechiae.
  • Henoch-Schönlein purpura (HSP): A form of vasculitis that affects blood vessels and is characterized by petechiae, among other symptoms, often seen in children.