We have discussed ITP (Immune Thrombocytopenia Purpura) previously, but given that it is a common pediatric hematologic disorder, it is worth a repeat visit. Here are a few quick interesting morsels to keep in mind:
ITP is not a platelet function problem… it is a platelet destruction problem.
- Autoantibodies that target the patients platelets lead to a shortened lifespan of the platelet.
- Normally, platelets last 8-10 days. When autoantibodies coat them, they are removed from the circulation after a few hours.
- Production of platelets can also be impaired.
- BUT… the platelets that are present are typically younger and functional (this is one trait that distinguishes it from malignancies).
Bleeding signs are more important that Platelet Count!
- We often become fixated upon numbers, but we should focus on physical exam and signs of bleeding.
- The diagnosis of ITP requires a plt count of <100,000 /microLitres… so we are already focusing on the number.
- Interestingly, profound thrombocytopenia on initial presentation is actually reassuring.
- Initial platelet counts of <20,000 are commonly seen in cases of uncomplicated ITP.
- Platelet counts of 40,000 – 90,000 are more concerning for undiagnosed marrow failure or leukemia.
- Platelet counts of <20,000 can be quite attention grabbing!
- Occasionally, we may even convey a sense of emergency to the family when we see such low numbers, only to have to backtrack and let the family know that the hematology specialist is “ok” with that number and that it is safe to go home.
- Again… the number is important, but only part of the story.
- It will be important to convey to the hematologist some physical exam findings:
- Cutaneous Bleeding
- Mucous Membrane
- Wet Purpura – Buccal mucosa, Gingiva, palate, tonsillar pillar purpura or petchiae
- Melena / GIB
- CNS hemorrhage (fortunately, rare (<1%))
- Joint / Muscle
- Cutaneous Bleeding
- ITP management is typically based upon clinical findings, rather than platelet count.
- Mild ITP
- Bruising and petechiae
- Occasional mild epistaxis
- Very little or no interference with daily living
- More severe skin manifestations
- Some mucosal lesions (Wet Purpura)
- More troublesome epistaxis and menorrhagia
- Bleeding (epistaxis, melena, and/or menorrhagia requiring hospitalization and/or transfusion.
- Serious interference with quality of life
- Mild ITP
- There is proposed scoring system to help determine management (Buchanan 2002), which is also solely based on clinical findings.
- Skin (degree of petechiae and bruises)
- Epistaxis (mild to active bleeding)
- Oral (petechiae on the palate to mucosal bleeding)
- Overall (mild skin findings without mucosal involvement to internal hemorrhage)
One of the biggest concerns is whether the child is at risk of ICH.
- Many hematologists will consider the presence of wet purpura as a sign of more significant risk and have a lower threshold to provide therapy for those children.
- The patient population that is truly at risk for ICH is still being better characterized and defined.
- Interestingly, some evidence that patients with head trauma and hematuria or other hemorrhages besides mild mucocutaneous bleeding are at increased risk for developing ICH even with platelet counts >20,000.
In all honesty, the management strategy varies from provider to provider, but what all pediatric hematologists will be most interested in is the physical exam details. So, it is imperative that we look beyond the skin petechiae and look for any wet purpura… in addition to appreciating the degree of epistaxis or presence of hematuria!
D’Orazio JA, Neely J, Farhoudi N. ITP in Children: Pathophysiology and current treatment approaches. J Pediatr Hematol Oncol. 2013; 35: 1 – 13. Lambert MP. Childhood ITP: knowing when to worry? Blood. 2009; 114(23): 4758 – 4759. Buchanan GR. Bleeding signs in children with idiopathic thrombocytopenia purpura. J. Pediatr Hematol Oncol. 2003; 25(S1): S42 – S46. Buchanan GR, Adix L. Grading of hemorrhage in children with idiopathic thrombocytopenic purpura. J Pediatr. 2002; 141: 683 – 688. Bolton-Maggs PHB, Moon I. Assessment of UK practice for management of acute childhood idiopathic thrombocytopenic purpura against published guidelines. Lancet. 1997; 350: 620 – 623.