Idiopathic thrombocytopenic purpura (ITP) rare disease.

 

 

Idiopathic thrombocytopenic purpura (ITP), also known as primary immune thrombocytopenic purpura and autoimmune thrombocytopenic purpura, is defined as isolated thrombocytopenia with normal bone marrow and the absence of other causes of thrombocytopenia. The 2 distinct clinical syndromes manifest as an acute condition in children and a chronic condition in adults.

ITP is a decrease in the number of circulating platelets in the absence of toxic exposure or a disease associated with a low platelet count.

 

 

 

ITP is primarily a disease of increased peripheral platelet destruction, with most patients having antibodies to specific platelet membrane glycoproteins. Relative marrow failure may contribute to this condition, since studies show that most patients have either normal or diminished platelet production.

Acute ITP often follows an acute infection and has a spontaneous resolution within 2 months. Chronic ITP persists longer than 6 months without a specific cause.

 

 

 

 

Frequency

United States

The incidence of ITP in adults is approximately 66 cases per 1,000,000 per year.

An average estimate of the incidence in children is 50 cases per 1,000,000 per year.

New cases of chronic refractory ITP comprise approximately 10 cases per 1,000,000 per year.

International

According to studies in Denmark and England, childhood ITP occurs in approximately 10-40 cases per 1,000,000 per year. A study in Kuwait reported a higher incidence of 125 cases per 1,000,000 per year.

 

 

 

Mortality/Morbidity

Hemorrhage represents the most serious complication; intracranial hemorrhage is the most significant. The mortality rate from hemorrhage is approximately 1% in children and 5% in adults. In patients with severe thrombocytopenia, predicted 5-year mortality rates from bleeding are significantly raised in patients older than 60 years versus patients younger than 40 years, 47.8% versus 2.2%, respectively.

Older age and previous history of hemorrhage increase the risk of severe bleeding in adult ITP.

Spontaneous remission occurs in more than 80% of cases in children but is uncommon in adults.

Sex

In chronic ITP (adults), the female-to-male ratio is 2.6:1. More than 72% of patients older than 10 years are female.

In acute ITP (children), distribution is equal between males (52%) and females (48%).

Age

Peak prevalence occurs in adults aged 20-50 years.

Peak prevalence occurs in children aged 2-4 years.

Approximately 40% of all patients are younger than 10 years.

 

 

This make it a rare disease.