by Kathy Tjamaloukas, DPM
Resident 1st year
Northwest Medical Center
Margate, Florida

A 31 year old white female is brought into the emergency room with a several day history of malaise, fever, progression of a petechial-type rash all over the body, and respiratory symptoms, particularly shortness of breath and dyspnea on exertion.  In the emergency room, the patient is noted to be febrile with a temperature of 102.7, tachycardic with a heart rate of 157, and tachypneic with a respiratory rate of 31.  The blood pressure is 128/54.  Blood work reveals serum sodium of 119, potassium 3.6, chloride 80, CO2 of 20, BUN 80 with creatinine of 2.3.  Liver function tests are additionally elevated, predominantly with a bilirubin of 8.8, and chest x-rays demonstrate diffuse bilateral pulmonary infiltrates.  Most notable at the time of the patient's presentation to the hospital is her platelet count of 12,000, a PTT of 40 seconds and a prothrombin time which is also elevated at 16 seconds.  Her D-dimer is positive at 0.5 to 1.0.  The patient apparently has severe thrombocytopenia and is appropriately given blood transfusions.

Due to the patient's critical condition and progressive deterioration, she is transferred to the intensive care unit and intubated due to respiratory failure.  She is given various broad spectrum I.V. antibiotics and begun on aggressive supportive care.  She is seen and evaluated by numerous consultants including nephrology, infectious disease and cardiology.  Her blood cultures, at this juncture, reveal gram positive cocci.

No history can be obtained from the patient and most of the information is provided by the patient's mother at bedside.  The patient apparently has a known history of IV drug abuse.  Further review of the patient's history indicates that she has been taking high doses of various pain medications as well.  Most notable on physical examination is that the patient has a diffuse purpuric rash all over her body, predominantly on her hands and lower extremities.  There are areas of purpura with overlying hemorrhagic bullae primarily on the medial aspect of the ankles.  At this juncture, cutaneous punch biopsies from representative sites of involvement are obtained.  Microscopic evaluation of these lesions demonstrates superficial perivascular neutrophilic infiltrate and microthrombi within the vessels.

Now it's time to act, Doctors.  You just saw this patient and reviewed the lab test results.

Upon reviewing the above information, what are your most likely differential diagnoses and what would you do next ?