A 32-year-old woman presents to an urgent care clinic with a sore throat, subjective fever, and abnormal bruising. She states that her sore throat has been getting gradually worse for approximately 5 days. She denies any cough, runny nose, shortness of breath, jaw stiffness, or change in her voice. The bruises are few, small, scattered, and painless. She also denies any history of a significant injury and active medical problems, but she thinks that she had bruises such as this once before as a child and was hospitalized for it.


A review of the nursing notes shows that the patient’s vital signs are normal at triage except for a temperature of 100.1° F orally. Her pulse was 88 bpm, and her blood pressure was 115/88 mm Hg.

Head and neck examination reveals that her tonsils are inflamed with mild exudate. She has no stridor, drooling, hoarse voice, or trismus. Her heart and lung exams are both normal.

Continue Reading

Her skin exam shows a few nonimpressive, fingertip-sized bruises on her thighs and arms and one on her abdomen. She states that there was no injury and these bruises “came out of nowhere.” There are no petechiae or other skin lesions noted. See the image below, which shows one of the bruises.

Laboratory workup

Chemistries and coagulation are normal. A complete blood count shows a platelet count of 60 (baseline 250) and a hemoglobin count of 9.5 (baseline 13). 

What is the differential diagnosis for thrombocytopenia? 
What other testing should be performed?

Click to the next page for answers