Purpura is purple or red discoloration caused by blood leaking from small vessels into the skin, so the spots do not fade when pressed. It can come from a low platelet count, a clotting problem or inflamed vessels, and with fever it can signal a life-threatening infection.
Key symptoms
- Purple or red spots that appear without a clear injury
- Easy bruising, nosebleeds or bleeding gums
- Heavy menstrual periods or blood in urine or stool
- Joint pain, belly pain or rash on the legs in vasculitis
- Fever, feeling very unwell or recent new medicines
What you find on exam
- Spots that do not blanch with pressure; petechiae are tiny, purpura larger
- Flat purpura suggests a platelet or clotting problem; raised (palpable) purpura suggests vasculitis
- Pattern and location: legs and buttocks in IgA vasculitis
- Bleeding in the mouth, gums or eyes
- Enlarged spleen, liver or lymph nodes, and vital signs for shock
Tests
- Blood count with platelet count and a blood smear
- Clotting tests: PT/INR, aPTT and fibrinogen
- Kidney function and urinalysis for blood or protein in vasculitis
- Blood cultures if fever; skin biopsy for palpable purpura
Treatment basics
- Fever with purpura: blood cultures and IV ceftriaxone right away
- Stop any medicine that may be the cause, such as anticoagulants or new drugs
- Immune thrombocytopenia: observation, or corticosteroids and IVIG if bleeding or very low platelets
- Suspected TTP: urgent plasma exchange with a hematologist
- Supportive care and specialist follow-up for vasculitis
Red flags
- Fever with a fast-spreading purple rash or signs of shock
- Active bleeding, blood in vomit or stool, or a severe headache
- Confusion, low platelets and anemia together (possible TTP)
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.