A 27-year-old woman arrives with purple pinpoints scattered across her legs and fresh bruises blooming along her forearms. She says her gums bled while brushing her teeth this morning, and her partner noticed she was “not quite herself” during the drive in. In the triage chair, she develops a sudden, severe headache and asks the nurse what the spots mean. The CBC and smear are still pending.

— What’s your move? Read on.

Before you read
  • What single bedside distinction separates platelet failure from coagulation-factor failure?
  • When should empiric treatment begin before confirmatory testing?

When to Think of It

Enter purpura into the differential with nonblanching petechiae, palpable purpura, ecchymoses, mucosal bleeding, or rapidly progressive skin discoloration. Fever, hypotension, altered mental status, severe headache, renal injury, neurologic findings, pregnancy/postpartum state, new medications, or hemolysis should raise the urgency.

Sick or Not Sick

The key call is stable isolated skin findings versus systemic illness with possible infection, DIC, TTP, or profound thrombocytopenia. Shock, rapidly spreading purpura, fever, encephalopathy, focal neurologic findings, renal failure, or active bleeding means resuscitation and specialty consultation now—not outpatient dermatology.

The First Fifteen Minutes

  • Place on monitor; obtain two IVs, bedside glucose, CBC with smear, PT/INR, aPTT, fibrinogen, CMP, lactate, type and screen, urinalysis, pregnancy test, and blood cultures if febrile.
  • If septic appearance, fever, or rapidly progressive purpura suggests meningococcemia: ceftriaxone 2 g IV now, because rapid bactericidal therapy reduces invasive meningococcal mortality. Add vancomycin 15–20 mg/kg IV when resistant pneumococcus or an undifferentiated bacterial meningitis syndrome remains plausible; check institutional dosing/renal-adjustment guidance.
  • If TTP is strongly suspected—thrombocytopenia plus microangiopathic hemolytic anemia, neurologic findings, renal injury, or fever—send ADAMTS13 before therapy if it will not delay treatment and call hematology for plasma exchange. Give methylprednisolone 1 g IV daily when hematology agrees, because immune suppression reduces ongoing autoantibody-mediated ADAMTS13 inhibition; regimen varies by protocol.
  • If life-threatening bleeding with severe thrombocytopenia: platelet transfusion is generally one adult apheresis unit IV, because it temporarily raises the platelet mass; avoid routine platelet transfusion in suspected TTP unless hemorrhage is immediately life-threatening or directed by hematology.
  • If major hemorrhage or DIC with low fibrinogen: activate a massive-transfusion protocol as indicated; cryoprecipitate dosing varies by laboratory and product, commonly 10 units IV, because it restores fibrinogen. Use the institutional transfusion protocol.
  • If hypotension: crystalloid 500–1,000 mL IV bolus, reassessing perfusion; if shock persists, norepinephrine 0.05–0.1 mcg/kg/min IV infusion, titrated to a MAP around 65 mm Hg, because vasoconstriction restores perfusion pressure.

Definitive Care & Disposition

Treat the cause: plasma exchange urgently for suspected TTP; antibiotics and source control for sepsis; stop offending medications; manage DIC with treatment of the underlying process and targeted blood products. Admit patients with systemic symptoms, severe thrombocytopenia, active bleeding, hemolysis, coagulopathy, renal injury, or diagnostic uncertainty. ICU care is appropriate for shock, neurologic deterioration, respiratory compromise, rapidly progressive purpura, or need for plasma exchange or massive transfusion. Stable, isolated, mild purpura with reassuring testing may receive expedited hematology or dermatology follow-up.

How This One Kills

The dangerous miss is labeling purpura “ITP” without reviewing the smear and hemolysis markers, allowing TTP to progress to irreversible neurologic injury, renal failure, or death while awaiting ADAMTS13.
The Differential — What Else Looks Like This
  • Petechiae from isolated thrombocytopenia — normal coagulation studies and no hemolysis; confusing it with TTP delays plasma exchange.
  • DIC — prolonged PT/aPTT, elevated D-dimer, and low fibrinogen; confusing it with TTP leads to the wrong blood-product and source-control strategy.
  • Meningococcemia — fever, toxicity, rapidly spreading purpura, shock; confusing it with a noninfectious rash delays antibiotics.
  • Small-vessel vasculitis — palpable, often dependent purpura with renal or joint involvement; confusing it with sepsis may delay biopsy and immunologic evaluation.

The Second-Day Story

Older adults may present with weakness, confusion, or anemia rather than obvious bleeding; patients with dark skin may have purpura that is easier to feel than see; and partially treated sepsis may lack fever. Do not let a modest-appearing rash reassure you: palpate for nonblanching lesions, inspect mucosa, trend mental status and urine output, and use the smear, platelet count, hemolysis profile, and coagulation studies to identify systemic disease.
Back to Our Patient
Back to our 27-year-old woman: her petechiae, mucosal bleeding, headache, and confusion make this a sick purpuric presentation, not an outpatient rash. The CBC shows severe thrombocytopenia, hemoglobin is low, creatinine is elevated, smear shows schistocytes, and coagulation studies are near normal—recognition of suspected TTP. After blood is sent for ADAMTS13 without delaying treatment, hematology is called, methylprednisolone 1 g IV is given, and she is transferred emergently for plasma exchange and ICU monitoring.
Patient Presentation to Attending
How you’d present this patient on the floor — tight, pertinent positives and negatives, no rambling
“This is a 27-year-old woman with acute petechiae, mucosal bleeding, headache, and new confusion. Symptoms began today without trauma, and she has no fever, diarrhea, pregnancy, or known liver disease. She is tachycardic but maintaining pressure, with diffuse nonblanching petechiae and scattered ecchymoses, without meningismus or focal infection. Her CBC shows severe thrombocytopenia and anemia, the smear has schistocytes, creatinine is elevated, and PT and aPTT are near normal. I’m concerned for TTP rather than isolated thrombocytopenia or DIC, so I’ve sent ADAMTS13, called hematology, started empiric steroid therapy, and am arranging emergent plasma exchange and ICU admission.”

Study Directive

  • Draw a bedside algorithm separating platelet disorders, coagulation disorders, vasculitis, and sepsis.
  • Memorize the TTP pattern: thrombocytopenia + MAHA + neurologic/renal features + usually normal coagulation studies.
  • Review one peripheral smear and identify schistocytes, spherocytes, blasts, and giant platelets.
  • Practice stating the empiric management of suspected TTP in one sentence without waiting for ADAMTS13.