Approach to child with purpura
Ahmed S.Barefah KAAU,MBBS
Questions
• What is the definition of purpuric rash?
• What are the causes of purpura?
• How to approach such a case?
Definition
• red, nonblanching maculopapular lesions caused by intradermal capillary bleeding.
• classified as
o petechiae (pinpoint hemorrhages less than 2 mm in greatest diameter),
o purpura (2 mm to 1 cm) or o ecchymoses (more than 1 cm).
• results from the extravasation of blood from the vasculature into the skin or mucous membranes.
Causes
Pupura
Platelet Vascular
Function
Count Congenital Acquired
Thrombocytopenia
• may be caused by
– increased platelet destruction
• Immune
• nonimmune
– decreased platelet production
• Congenital
• Acquired
– sequestration of platelets.
Immune Thrombocytopenia
• Idiopathic (immune) thrombocytopenic purpura
– by far the most common etiology of thrombocytopenia in childhood.
– caused by the development of IgG autoantibodies to platelet membrane antigens as a result of an
unbalanced response to an infectious agent or autoimmunity
– sudden onset of bruises, purpura, mucosal
hemorrhage and petechiae in a child who is otherwise in excellent health.
ITP
– antecedent viral infection is common.
– The peak incidence is between two and four years of age.
– 80 to 90 percent of children recovering within six to 12 months.
– Chronic idiopathic thrombocytopenic purpura is more likely to present in teenage girls and children with underlying immune disorders. It has a more insidious onset
Immune Thrombocytopenia
• Drugs
– penicillin, valproic acid (Depakene), quinidine, sulfonamides, cimetidine (Tagamet) and heparin.
• Post-transfusion purpura
– acute onset of thrombocytopenia approximately five to 14 days after a transfusion.
• Rarely
– HIV, CMV, HSV – 10% of SLE cases
Immune Thrombocytopenia
• Neonatal isoimmune (alloimmune) thrombocytopenia
• Neonatal autoimmune thrombocytopenia
Non-Immune Thrombocytopenia
• hemolytic-uremic syndrome
– triad of microangiopathic hemolytic anemia, thrombocytopenia and acute renal injury.
– infection by verocytotoxin-producing Escherichia coli
• thrombotic thrombocytopenic purpura
– occurs more often in adults, and neurologic
(rather than renal) symptoms are more prominent
Non-Immune Thrombocytopenia
• disseminated intravascular coagulopathy
– overwhelming sepsis, incompatible blood
transfusion, snake bite, giant hemangioma and malignancy.
• Purpura fulminans
– acute, often lethal syndrome of DIC.
– may develop because of a severe bacterial infection, notably meningococcal disease, or because of protein C or S deficiency
Decreased Platelet Production
• Congenital
– Thrombocytopenia absent radii (TAR) syndrome
• inherited as an autosomal recessive trait
– Fanconi anemia
• pancytopenia, hyperpigmentation and café au lait spots, short stature, skeletal abnormalities
– Wiskott-Aldrich syndrome
Decreased Platelet Production
• Acquired
– Bone marrow suppression
• Drugs such as alkylating agents, antimetabolites,
anticonvulsants, chlorothiazide diuretics and estrogens
• Infection as viral and bacterial infections, especially septicemia and Intrauterine infection with TORCH organisms
– Bone marrow infiltration
• patients with leukemia, histiocytosis, storage diseases, neuroblastoma, myelofibrosis and osteopetrosis
Sequestration of Platelets
• Splenomegaly or giant hemangioma can result in thrombocytopenia because of platelet
sequestration.
• The association of thrombocytopenia and
giant hemangioma is referred to as Kasabach- Merritt syndrome.
Platelet Dysfunction
• Glanzmann's thrombasthenia
– autosomal recessive disorder caused by congenital deficiency in the platelet membrane glycoproteins IIb and IIIa.
• Bernard-Soulier disease
– autosomal recessive disorder caused by a congenital deficiency in platelet membrane glycoprotein Ib
Vascular Factors
• Congenital Causes
– Hereditary hemorrhagic telangiectasia
• autosomal dominant disorder
• development of fragile telangiectasia of the skin and mucous membranes
– Ehlers-Danlos syndrome
• characterized by skin hyperelasticity, joint
hypermobility and fragility of the skin and blood vessels
Vascular Factors Acquired Causes
• Henoch-Schönlein purpura
– IgA-mediated systemic vasculitis of small blood vessels
– nonthrombocytopenic purpura, abdominal pain, arthritis and nephritis
– the most common form of vasculitis in children – history of a preceding URTI
– Characteristically palpable, gravity dependant purpura
Vascular Factors Acquired Causes
• Meningococcemia and rickettsial diseases may cause direct damage to blood vessels, with
resultant purpura.
• Child abuse
History
• Age of Onset
• Birth Intrauterine infection, maternal idiopathic thrombocytopenic purpura, maternal systemic lupus erythematosus, maternal medication, TAR syndrome, congenital amegakaryocytic
thrombocytopenia
• 2 to 4 years Idiopathic thrombocytopenic purpura
• 4 to 7 years Henoch-Schönlein purpura
History
• Onset/chronicity
• Acute onset ITP, HSP, medication, mechanical cause
• Long duration Abnormality of platelets, coagulopathy
History
• Pattern of bleeding
• Mucosal bleeding Thrombocytopenia, von Willebrand's disease
• Intramuscular and intra-articular bleeding Hemophilia
History
• Associated symptoms
• Abdominal pain, blood in stools, joint pain
• HSPLethargy, fever, bone pain Leukemia
• Intermittent fever, muscoskeletal symptoms
• SLELethargy, polyuria, polydipsia, failure to thrive Uremia
• Purpura, but otherwise healthy ITP
History
• Past health
• Antecedent viral infection, especially an upper respiratory tract infection ITP, HSP
• Drug use
• Family history
• Maternal history
• Social history
Examination
• General findings
• Poor growth Chronic disorder Fever Hypertension Infection Chronic renal
failure,renal vasculitis
Examination
• Characteristics of purpura
• Location on lower extremeties Henoch- Schönlein purpura
• Location on palms and soles Rickettsial infection
• Palpable purpura Vasculitis
Laboratory Evaluation
• A thorough history and a careful physical examination are critical first steps in the evaluation of children with purpura.
RED FLAGS
Fever,
lethargy,
weight loss, bone pain, joint pain, pallor,
Lymphadenopathy
hepatosplenomegaly
Summary
• Petechiae and purpura result from a wide variety of underlying disorders and may occur at any age
• red, nonblanching maculopapular lesions caused by intradermal capillary bleeding
• Classified into platelet or vascular causes
• Idiopathic thrombocytopenic purpura is the most common cause of thrombocytopenia in children.
• Henoch-Schönlein purpura is the most common form of vasculitis in children, and the purpuric rash is almost always palpable.
