Prepared by Amber R. Stonehouse, MD, Chief Resident, and James Studdiford, MD, Associate Professor, Department of Family and Community Medicine, Thomas Jefferson University Hospital, Philadelphia, PA
A 52-year-old woman presented to the emergency department reporting a 1-week history of rash on her bilateral lower extremities and "spots under her tongue." She noted no similar rashes in the past nor any recent trauma, viral infection, fever, sick contacts, overt bruising, hematuria, melena, hematochezia, epistaxis, gingival bleeding, or menorrhagia. Her medical history included lupus, congestive heart failure, hypertension, hypothyroidism, and anemia of chronic disease.
Physical examination revealed petechiae over her bilateral lower extremities as well as palatal and subungual petechiae (Figures 1, 2). The lesions were asymptomatic and the remainder of her physical examination was normal. Laboratory studies revealed a white blood cell count of 4,000/μL (normal, 4,500-11,000/μL); hemoglobin of 10.7 g/dL (normal, 12.0-15.0 g/dL), which was a stable level compared with her baseline; hematocrit of 35.9% (normal, 35%-45%); and a platelet count of 6 x103/μL (normal, 14-40 x103/μL). Her liver function tests, Epstein-Barr virus titer, human immunodeficiency virus test, and hepatitis panel were all negative.
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| Figure 1 | Figure 2 |
What's Your Diagnosis?
- Chronic disseminated intravascular coagulation
- Idiopathic thrombocytopenic purpura
- Leukocytoclastic vasculitis
- Meningococcemia
Quiz Answer
Idiopathic thrombocytopenic purpura (ITP)—The patient was admitted to the hospital, after which a diagnosis of ITP was made. She was treated with prednisone, 100 mg daily, and a 5-day course of intravenous immunoglobulin (IVIG). During hospitalization, her platelet count reached a high of 27 x103/µL, and she experienced no overt bleeding.
ITP is an acquired disorder of unclear etiology. The pathogenesis of ITP is thought to be related to platelet destruction or inhibition of platelet production.1 A presumptive diagnosis of ITP is made when the patient's history, physical examination, complete blood count, and examination of the peripheral blood smear do not suggest other etiologies for the patient's isolated thrombocytopenia. Recommended additional tests include screenings for human immunodeficiency virus and hepatitis C in patients with appropriate risk factors.2 Thyroid function testing to exclude the infrequent presence of occult hyperthyroidism or hypothyroidism may also be considered. A bone marrow biopsy is indicated in patients over 60 years of age to rule out myelodysplastic syndrome.3 The American Society of Hematology ITP Practice Guideline Panel does not recommend antiplatelet antibody studies in patients thought to have ITP.2
The major goal of ITP treatment is to provide a safe platelet count (thought to be >10 x103/µL) in order to prevent major bleeding.2 In adults, standard practice is to initiate treatment with prednisone, 1 mg/kg, given as a single daily dose. The duration of initial prednisone treatment is determined by the response in the platelet count. High-dose oral dexamethasone (Decadron), high-dose intravenous methylprednisolone (Medrol), and IVIG are reserved for cases refractory to oral prednisone therapy. Splenectomy is the traditional second-line treatment in adults with ITP who fail to achieve a safe platelet count with steroid treatment.
Chronic disseminated intravascular coagulation (DIC), also known as compensated DIC, develops when blood is continuously exposed to small amounts of tissue factor, and compensatory mechanisms in the liver and bone marrow are unable to replenish the depleted coagulation proteins and platelets.4 In cases of chronic DIC, there is a slower rate of consumption of coagulation factors balanced by enhanced synthesis of these proteins; consequently, the platelet count may be only moderately reduced. Solid tumors are the most common cause of chronic DIC.
Leukocytoclastic vasculitis, also known as hypersensitivity vasculitis, is a disorder typically caused by drugs that stimulate an immune response. The presence of palpable petechiae or purpura is generally a major finding in hypersensitivity vasculitis. Other clinical findings include fever, urticaria, arthralgias, lymph-adenopathy, low serum complement levels, and an elevated erythrocyte sedimentation rate.5
Acute systemic meningococcal disease typically presents with fever, nausea, vomiting, headache, and myalgias in an otherwise healthy patient. The patient may have a petechial rash, which is generally seen on the trunk and lower extremities. The mucous membranes of the soft palate and the ocular and palpebral conjunctiva may also show signs of hemorrhage. Over 50% of patients with meningococcal infections will have petechiae upon presentation.6
References
- Cooper N, Bussel J. The pathogenesis of immune thrombo-cytopaenic purpura. Br J Haematol. 2006;133:364-374.
- George JN, Woolf SH, Raskob GE, et al. Idiopathic thrombocytopenic purpura: a practice guideline developed by explicit methods for the American Society of Hematology. Blood. 1996;88:3-40.
- British Committee for Standards in Haematology General Haematology Task Force. Guidelines for the investigation and management of idiopathic thrombocytopenic purpura in adults, children and in pregnancy. Br J Haematol. 2003;120:574-596.
- Levi M. Current understanding of disseminated intravascular coagulation. Br J Haematol. 2004;124:567-576.
- Calabrese LH, Duna GF. Drug-induced vasculitis. Curr Opin Rheumatol. 1996;8:34-40.
- Wolf RE, Birbara CA. Meningococcal infections at an army training center. Am J Med. 1968;44:243-255.
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