Differential Diagnosis for Non-Blanchable Petechial Rash
Single Most Likely Diagnosis
- Idiopathic Thrombocytopenic Purpura (ITP): This condition is characterized by low platelet count, leading to petechiae, purpura, and other bleeding manifestations. It is a common cause of non-blanchable petechial rash, especially in children and young adults.
Other Likely Diagnoses
- Viral Infections (e.g., Mononucleosis, CMV): Certain viral infections can cause a non-blanchable petechial rash, often accompanied by other symptoms like fever, sore throat, and lymphadenopathy.
- Medication-Induced Thrombocytopenia: Various medications, such as heparin, aspirin, and certain antibiotics, can induce thrombocytopenia, leading to a non-blanchable petechial rash.
- Vasculitis (e.g., Henoch-Schönlein Purpura): Vasculitis can cause a non-blanchable petechial rash, often accompanied by other symptoms like joint pain, abdominal pain, and renal involvement.
Do Not Miss Diagnoses
- Meningococcemia: This is a life-threatening condition caused by Neisseria meningitidis, characterized by a non-blanchable petechial rash, fever, and shock. Prompt recognition and treatment are crucial to prevent mortality.
- Disseminated Intravascular Coagulation (DIC): DIC is a condition characterized by widespread clotting and bleeding, which can cause a non-blanchable petechial rash. It is often associated with severe underlying conditions like sepsis, trauma, or cancer.
- Thrombotic Thrombocytopenic Purpura (TTP): TTP is a rare but life-threatening condition characterized by thrombocytopenia, microangiopathic hemolytic anemia, and renal failure. A non-blanchable petechial rash can be a presenting feature.
Rare Diagnoses
- Ehlers-Danlos Syndrome: This is a group of genetic disorders that affect connective tissue, leading to easy bruising, petechiae, and other skin manifestations.
- Scurvy: Vitamin C deficiency can cause a non-blanchable petechial rash, often accompanied by other symptoms like fatigue, malaise, and joint pain.
- Amyloidosis: This is a condition characterized by the deposition of abnormal proteins (amyloid) in various tissues, leading to a non-blanchable petechial rash and other systemic symptoms.