A Case Of Idiopathic Thrombocytopenic Purpura

An adolescent girl presents to the clinic with a rash that is made up of very small, bright red, non blanching macules. The girl had a non specific viral infection last week. She appears to be in excellent health except for the rash. She is not on any medications. 

What is the most common cause of this condition?

A. Penicillin

B. Hemolysis

C. Human immunodeficiency virus (HIV)

D. Lupus

E. Idiopathic thrombocytopenic purpura

Answer and Discussion: 

E.Idiopathic thrombocytopenic purpura 

Thrombocytopenia can be caused by decreased platelet production, increased platelet destruction, dilutional phenomena, platelet sequestration, or pseudothrombocytopenia. 

Common causes of platelet destruction include 

• DIC, 
• the anti-phospholipid antibody syndrome, 
• drugs such as heparin, 
• infections such as HIV and infectious mononucleosis, and 
• Idiopathic thrombocytopenic purpura (ITP). 

ITP is characterized by isolated, idiopathic thrombocytopenia. Purpura, bruising, and bleeding are encountered. Other symptoms like hepatosplenomegaly, lymphadenopathy, fever, or bone or joint pain are usually absent. Medications can cause thrombocytopenia and purpura, but we have no history of any medication use. 

Medications that can cause ITP include 

• penicillin, 
• valproic acid, 
• quinidine, 
• sulfonamides, 
• cimetidine, and 
• heparin. 

HIV and lupus are less common causes of ITP; viral illnesses will often be associated with ITP in children and young adolecents. Eighty to ninety percent of younger individuals recover in a few weeks, but ITP can be more recalcitrant in adults