Differential Diagnosis for Purpura-like Rash Spreading from Legs to Body
- Single most likely diagnosis
- Henoch-Schönlein Purpura (HSP): A form of vasculitis that typically presents with a purpura-like rash, often starting in the legs and spreading to other parts of the body. It is commonly seen in children and is associated with abdominal pain, arthritis, and renal involvement.
- Other Likely diagnoses
- Idiopathic Thrombocytopenic Purpura (ITP): An autoimmune condition characterized by low platelet count, leading to purpura, petechiae, and bruising. The rash can appear anywhere on the body, including the legs.
- Meningococcemia: A severe infection caused by Neisseria meningitidis, which can present with a purpura-like rash, often starting in the legs and spreading rapidly. It is a medical emergency.
- Vasculitis (e.g., ANCA-associated vasculitis): A group of conditions characterized by inflammation of blood vessels, which can cause a purpura-like rash, among other symptoms.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Disseminated Intravascular Coagulation (DIC): A condition characterized by widespread clotting and bleeding, which can present with a purpura-like rash. It is often associated with severe underlying conditions, such as sepsis or trauma.
- Thrombotic Thrombocytopenic Purpura (TTP): A rare blood disorder characterized by clotting and low platelet count, which can cause a purpura-like rash, among other symptoms.
- Sepsis: A life-threatening condition caused by a severe infection, which can present with a purpura-like rash, among other symptoms.
- Rare diagnoses
- Ehlers-Danlos Syndrome: A group of genetic disorders that affect connective tissue, which can cause easy bruising and a purpura-like rash.
- Pseudoxanthoma Elasticum: A rare genetic disorder that affects the skin, eyes, and cardiovascular system, which can cause a purpura-like rash.
- Amyloidosis: A group of conditions characterized by the deposition of abnormal proteins in tissues, which can cause a purpura-like rash, among other symptoms.