Purpuric skin lesions (petechiae, purpura, and ecchymoses) in children: Evaluation

INTRODUCTION — This review will discuss the evaluation of purpuric skin lesions in children. The causes of purpuric skin lesions, evaluation of bleeding in children, and sepsis (a major consideration for children with fever, petechiae, and/or purpura) are discussed separately:

●(See "Purpuric skin lesions (petechiae, purpura, and ecchymoses) in children: Causes".)

●(See "Approach to the child with bleeding symptoms".)

●(See "Sepsis in children: Definitions, epidemiology, clinical manifestations, and diagnosis" and "Septic shock in children in resource-abundant settings: Ongoing management after resuscitation".)

TERMINOLOGY — Purpuric skin lesions include (see "Approach to the clinical dermatologic diagnosis"):

●Petechiae – Petechiae are non-blanching red to purple macules that are pinpoint to 1 to 2 mm in size and are not raised (picture 1). Lack of blanching is often best appreciated by diascopy, which involves the use of a clear glass slide or drinking glass to apply pressure to the skin. They arise from bleeding into the skin from small capillaries.

Infection and thrombocytopenia are important causes of petechiae, although they may arise in other conditions.

●Purpura – Purpura are hemorrhagic lesions that are larger than petechiae and result from bleeding within the skin or mucous membranes from capillaries and other small blood vessels. Purpura can appear as non-blanchable dark red to dark purple macules, papules, patches, or plaques (picture 2A-B and picture 3 and picture 4). In some cases, purpura may be tender or painful. Purpuric papules are also called palpable purpura and indicate small vessel vasculitis.

Purpura occur in patients with infection, systemic vasculitis, thrombocytopenia, or coagulation disorders.

●Ecchymoses (bruises) – Ecchymoses reflect larger extravasations of blood arising from a hematoma or larger confluent purpura (picture 5). In addition to direct trauma, they can be associated with coagulation disorders and severe thrombocytopenia.

Skin color can influence the appearance of purpuric skin lesions; darker skin pigmentation can reduce the visibility of purpura (picture 2A-B).

INITIAL STABILIZATION — The initial approach should be dictated by the general appearance of the child and the presenting vital signs:

●Ill-appearing – An ill-appearing, lethargic child with petechiae or purpura with or without fever requires rapid diagnostic evaluation and emergency treatment for presumptive septic shock as summarized in the algorithm (algorithm 1) and discussed in detail separately. (See "Septic shock in children in resource-abundant settings: Rapid recognition and initial resuscitation (first hour)".)

An ill-appearing child with unexplained bruising requires assessment for signs of abuse (figure 1 and table 1) and, if suspicious findings are present, treatment of potentially life-threatening abusive head trauma or internal hemorrhage as discussed in the following topics:

•(See "Physical child abuse: Recognition".)

•(See "Trauma management: Approach to the unstable child".)

•(See "Severe traumatic brain injury (TBI) in children: Initial evaluation and management".)

•(See "Physical child abuse: Diagnostic evaluation and management".)

Further laboratory evaluation for specific hematologic causes is discussed below. (See 'Laboratory studies' below.)

●Well-appearing – A well-appearing child with fever and petechiae requires close monitoring and frequent re-evaluation for early signs of sepsis or septic shock (algorithm 2). A well-appearing child with petechiae and or purpura and normal vital signs can be approached with less urgency but still requires timely evaluation to identify the underlying cause. (See 'Well-appearing' below.)

EVALUATION

History — The patient's age, sex, clinical presentation, past medical history, and family history help to establish the most likely cause of purpuric skin lesions [1,2].

●Age – Severe congenital bleeding disorders usually present in the first year of life.

●Sex – Hemophilia is X-linked and only affects males (with rare exception). Von Willebrand is autosomal dominant and is seen with equal frequency in males and females.

●Fever – Serious infection is an important cause of petechiae and purpura in children and is usually, but not always, associated with fever.

●Symptom onset – The patient's recent and past medical history should be reviewed carefully with the parents/primary caregiver and child. Acute onset of purpuric skin lesions after a recent viral illness or immunization is consistent with an acquired disorder such as ITP. Recurrent purpura since infancy, however, suggests an inherited abnormality of platelets or clotting factors.

●Type of lesions and presence of bleeding – The site and type of bleeding manifestation may be helpful in establishing the alteration in the hemostatic mechanisms (table 2):

•Petechiae are most commonly seen in patients with thrombocytopenia and platelet disorders

•Mucosal bleeding (heavy menstrual bleeding, epistaxis) is common in platelet disorders and von Willebrand disease

•Soft tissue bruising and bleeding into the joints (hemarthroses) or muscles is common in patients with hemophilia or other clotting factor deficiencies

●Prior bleeding history – Prior bleeding during past surgeries (including circumcision), dental extractions, or significant trauma and the site of bleeding points to an alteration in hemostasis. Conversely, the absence of bleeding under these conditions would be unusual in most inherited disorders of even moderate severity.

●Family history of bleeding – The family history should be reviewed for purpura or bleeding disorders. A positive family history in male relatives on the maternal side suggests factor VIII or factor IX deficiency. A history of bleeding or bruising in numerous male and female family members suggests a condition with dominant inheritance such as von Willebrand disease. However, a negative family history does not exclude the diagnosis of von Willebrand disease or hemophilia. (See "Clinical manifestations and diagnosis of hemophilia" and "Clinical presentation and diagnosis of von Willebrand disease".)

●Recent medications – The clinician should note exposure to aspirin and other drugs known to affect platelet function.

Drug-induced vasculitis may be caused by numerous drugs including sulfonamides, penicillins, and phenytoin [3]. It usually develops within 7 to 21 days of starting the drug. (See "Purpuric skin lesions (petechiae, purpura, and ecchymoses) in children: Causes", section on 'Drug-induced vasculitis'.)

●Prescription anticoagulant or rat poison (warfarin or superwarfarin) poisoning – In general, oral intake of small amounts of rat poison (eg, single handful of superwarfarin product) or prescription anticoagulant would be unlikely to result in purpuric skin lesions or bleeding. Thus, patients with purpura in whom these ingestions are confirmed have likely had a large ingestion. (See "Management of warfarin-associated bleeding or supratherapeutic INR", section on 'Superwarfarin poisoning' and "Anticoagulant rodenticide poisoning: Clinical manifestations and diagnostic evaluation" and "Purpuric skin lesions (petechiae, purpura, and ecchymoses) in children: Causes", section on 'Vitamin K deficiency'.)

●Dietary history – Patients with severe malnutrition or restricted diets including patients with autism or avoidant/restrictive food intake disorder may be at risk for scurvy or vitamin K deficiency.

●Past medical history – Patients with underlying conditions such as uremia, hepatic disease, congenital heart disease, cancer or malabsorption may develop alterations in hemostasis (thrombocytopenia, platelet dysfunction or coagulopathy) that may present with purpura or bleeding.

Physical examination — All patients with purpuric skin lesions require a complete physical examination. Areas of particular focus include [1,4]:

●General examination – The overall appearance of a child will help guide further management. Patients who have purpuric skin lesions and are ill-appearing and/or hemodynamically unstable need to be rapidly assessed treated for presumed sepsis, especially children with fever (algorithm 2). (See 'Initial stabilization' above and 'Ill-appearing' below.)

●Fever – Infection is also an important consideration for all febrile children with purpuric skin lesions and requires further evaluation. (See 'Ill-appearing' below and 'Febrile' below.)

●Skin – The child should be examined carefully to assist in the diagnosis of the specific bleeding disorder and to evaluate hidden areas of hemorrhage. For petechiae and purpura, lack of blanching is often best appreciated by diascopy which involves the use of a clear glass slide or drinking glass to apply pressure to the skin. The distribution and size of the lesions should be noted:

•Petechiae – Important distributions include:

-Localized petechiae may appear in regions of known trauma such as a tourniquet site, bug bite, or other witnessed trauma; petechiae in the outline of a hand, finger, or other patterned object without a plausible history raises concern for abuse. Symmetric petechiae on the face or eyelids may accompany strangulation.

-Clustered petechiae in the distal extremities and/or subconjunctiva is a feature of bacterial endocarditis.

-Petechiae above the nipple line can be associated with frequent coughing or vomiting due to increased venous pressure and mechanical disruption of small blood vessels.

-Generalized petechiae points to systemic infection, thrombocytopenia, or platelet dysfunction.

•Purpura – Generalized purpura suggests serious conditions such as sepsis or vasculitis. Purpura localized to the lower body (buttocks, legs, ankles), with or without joint swelling in the hands or feet, suggests immunoglobulin A vasculitis (IgAV; Henoch-Schönlein purpura [HSP]). The face, trunk, and upper extremities may be involved in non-ambulatory children. (See "IgA vasculitis (Henoch-Schönlein purpura): Clinical manifestations and diagnosis", section on 'Clinical manifestations in children'.)

•Ecchymoses (Bruises) – Non-painful, palpable (lumpy) bruises are often seen in children with severe hemophilia. The following types of bruising suggest child abuse (table 1) (see "Physical child abuse: Recognition", section on 'Inflicted bruises'):

-Recognizable pattern (figure 1), such as a loop mark (picture 6 and picture 7), ligature mark, belt or hand print (picture 8)

-Bruises in multiple stages of healing in areas atypical for unintentional trauma (picture 9)

-Bruising in very young infants or non-cruising children (table 3)

-While bruises are often common on the extensor surfaces of active young children, multiple bruises (>5) at the same time or bruises in areas not often exposed (abdomen, chest, back) are more common in disorders of hemostasis.

●Eyes – An isolated subconjunctival hemorrhage in infants outside of the neonatal period and, when funduscopic examination is possible, retinal hemorrhages, especially numerous hemorrhages involving multiple layers, should raise suspicion for child abuse. (see "Physical child abuse: Recognition", section on 'Inflicted bruises' and "Child abuse: Eye findings in children with abusive head trauma (AHT)", section on 'Retinal hemorrhages')  

●Oropharynx – Important findings include:

•Oral vesicles on the buccal mucosa, tongue, or soft palate in patients with petechiae or purpura suggests a viral etiology (eg, echovirus 9 or coxsackievirus A9). (See "Enterovirus and parechovirus infections: Clinical features, laboratory diagnosis, treatment, and prevention", section on 'Exanthema and enanthems'.)

•Palatal petechiae or blood blisters may occur in patients with immune thrombocytopenia (ITP).

•Palatal petechiae and exudative pharyngitis may indicate infection with S. pyogenes or Epstein-Barr virus.

●Lymph nodes – Generalized lymphadenopathy may be present in certain malignancies (leukemias) or viral infections (infectious mononucleosis, CMV) that can present with purpura.

●Abdomen – Hepatomegaly may signal an underlying hepatic disorder or leukemia. Splenomegaly can be seen in infectious mononucleosis, leukemia, hepatic disease, and the storage diseases.

●Extremities and joints – Inflammation or synovial thickening of the large joints is consistent with hemarthroses seen in hemophilia or arthritis associated with IgAV (HSP).

Children with IgAV (HSP) may also have painful swelling of the feet that makes them unable or reluctant to walk.

●Central nervous system – Complete neurologic assessment is mandatory and should focus on mental status, signs of increased intracranial pressure, or focal findings in patients with a potential disorder of hemostasis and intracranial bleeding. (See "Severe traumatic brain injury (TBI) in children: Initial evaluation and management".)

DIAGNOSTIC APPROACH — A systematic approach to the evaluation of a child with petechiae and/or purpura helps to guide the workup and identify the appropriate treatment [5,6]. The extent and pace of diagnostic testing depends upon the child's appearance and whether fever is present or absent.

Ill-appearing — Children with purpuric skin lesions who are ill-appearing require rapid stabilization and treatment targeted to the most likely cause based upon the presence of fever and other clinical findings [2]:

●Febrile – Ill-appearing children with fever, shock, and petechiae or purpura require emergency resuscitation, ancillary studies, and empiric antimicrobial agents for presumed sepsis or septic shock as described in the algorithm (algorithm 1). (See "Septic shock in children in resource-abundant settings: Rapid recognition and initial resuscitation (first hour)".)

For children with septic shock, broad-spectrum IV antimicrobial therapy should begin within one hour of presentation, preferably after obtaining appropriate cultures.

Empiric antibiotics are chosen to cover all likely pathogens based upon the patient's age, presentation, comorbidities, and local pathogen resistance. Consultation with an expert in pediatric infectious disease is strongly encouraged. Children with shock should undergo appropriate resuscitation before lumbar puncture (LP). As an example, a hemodynamically unstable patient with septic shock who may have bacterial meningitis should undergo emergency fluid resuscitation, have a blood culture obtained, and receive empiric antibiotics as soon as possible; LP should be deferred until the child's condition stabilizes. (See "Septic shock in children in resource-abundant settings: Rapid recognition and initial resuscitation (first hour)", section on 'Empiric regimens'.)

In these patients, results of the complete blood count, peripheral smear, and coagulation studies (PT, INR, PTT) may indicate DIC or suggest other important underlying etiologies that warrant further evaluation and management as directed by a pediatric hematologist/oncologist as described below. (See 'Laboratory studies' below.)

Occasionally, infants and young children with abusive head trauma and intracranial hemorrhage (eg, subdural hematoma) may present with fever from meningeal irritation with coma and/or seizures. These children also can have signs of increased intracranial pressure and suspicious petechiae or ecchymoses as well as other red-flag injuries of child abuse (table 1). In addition, hemorrhage caused by internal injuries such as a liver laceration may be present and require trauma resuscitation. (See "Severe traumatic brain injury (TBI) in children: Initial evaluation and management" and "Trauma management: Approach to the unstable child".)

●Afebrile – There are several diagnoses (including infection) that may present in the afebrile, ill-appearing child with purpuric skin lesions [2]. For all ill-appearing patients, the clinician should also maintain a high suspicion and treat for sepsis and septic shock. (See "Purpuric skin lesions (petechiae, purpura, and ecchymoses) in children: Causes".)

Child abuse is of particular concern and is indicated by red-flag physical findings, especially suspicious bruising (table 1). These children may require trauma resuscitation, preferably by a pediatric trauma surgeon at a level 1 pediatric trauma center, and, if present, stabilization of severe traumatic brain injury. (See "Trauma management: Approach to the unstable child" and "Severe traumatic brain injury (TBI) in children: Initial evaluation and management".)

Laboratory studies — For ill-appearing children with petechiae, purpura, and/or extensive bruising, initial screening tests should include [4]:

●CBC with differential and peripheral smear – These studies establish abnormalities in platelet number, the presence of abnormalities in other hematologic cell lines (eg, anemia, leukopenia), and provides evidence for intravascular hemolysis.

●Prothrombin time (PT) with an international normalized ratio (INR) – These studies test the extrinsic clotting pathway (factors VII, IX, II, X, V, fibrinogen).

●Activated partial thromboplastin time (aPTT) – This study tests the intrinsic pathway (factors HWMK, kallikrein, XII, XI, IX, VIII, II, X, V, fibrinogen) (figure 2).

●Fibrinogen and D-dimer – In addition to the studies above, these tests assess for disseminated intravascular coagulopathy (DIC). (See "Disseminated intravascular coagulation in infants and children", section on 'Laboratory findings'.)

●Inflammatory biomarkers – Elevated C-reactive protein and, when results are rapidly available, procalcitonin point to invasive bacterial infection.

●Blood culture – At minimum, a blood culture should be obtained in all ill-appearing children. Other cultures are warranted in febrile children with concern for sepsis and septic shock, as described below.

In patients with a suspected bleeding disorder, discriminating laboratory studies should be obtained based on the results of the initial screening tests and the clinical setting (table 4). Details of testing, including nonmedical causes for abnormal results, are discussed separately. (See "Clinical use of coagulation tests" and "Approach to the child with bleeding symptoms", section on 'Initial laboratory evaluation'.)

Additional studies are indicated based on clinical suspicions for the following diagnoses:

●Sepsis/septic shock with DIC – Studies are provided in the table and algorithm (algorithm 1) and discussed separately. (See "Sepsis in children: Definitions, epidemiology, clinical manifestations, and diagnosis", section on 'Laboratory studies'.)

●Physical child abuse – In consultation with a child abuse specialist, studies to evaluate for other injuries are provided in the table (table 5) and discussed separately. (See "Physical child abuse: Diagnostic evaluation and management".)

Notification of Child Protective Services is also required. (See "Child abuse: Social and medicolegal issues".)

●Intravascular hemolysis/hemolytic anemia – In consultation with a pediatric hematologist and oncologist, further studies include (see "Overview of hemolytic anemias in children", section on 'Diagnostic approach'):

•Reticulocyte count

•Lactate dehydrogenase (LDH)

•Total and indirect bilirubin

•Plasma free hemoglobin

•In children >18 months old, haptoglobin

•If hemolytic anemia is suspected, direct antiglobulin test (formerly called Coombs test)

•If not already obtained, serum electrolytes, blood urea nitrogen, and creatinine

Interpretation — Abnormalities on initial testing in ill-appearing children with purpuric skin lesions provide evidence for specific etiologies that require further laboratory evaluation and management as directed by a pediatric hematologist/oncologist:

●Anemia and thrombocytopenia – These findings suggest:

•Bone marrow infiltration (malignancy) – Cancers that are commonly present with purpuric skin lesions include:

-Acute leukemia – These patients may have a low, normal, or high WBC; blastocytes may be seen on peripheral smear. (See "Overview of the clinical presentation and diagnosis of acute lymphoblastic leukemia/lymphoma in children" and "Acute myeloid leukemia in children and adolescents".)

-Neuroblastoma – Clinical features in children with neuroblastoma include periorbital ecchymoses, proptosis, abdominal mass, Horner syndrome (miosis, ptosis, and an anhidrosis), hypertension, and opsoclonus myoclonus syndrome. (See "Clinical presentation, diagnosis, and staging evaluation of neuroblastoma".)

Findings of disseminated intravascular coagulation (decreased fibrinogen, prolonged PT, INR, and aPTT) with bleeding suggestive of sepsis are also associated with acute myelocytic leukemia or, in children with hepatitis, inflammatory central nervous system findings (ie, seizures, mental status changes, or ataxia), or both, hemophagocytic lymphohistiocytosis. Microscopy and specialized testing of bone marrow specimens are required for definitive diagnosis. (See "Clinical features and diagnosis of hemophagocytic lymphohistiocytosis".)

•Microangiopathic anemia – Findings of intravascular hemolysis and acute kidney injury to hemolytic uremic syndrome (HUS) and thrombocytopenic purpura (TTP). TTP is rare in the pediatric population but more common in adolescents than younger children. Further evaluation and management of these conditions are discussed separately. (See "Diagnostic approach to suspected TTP, HUS, or other thrombotic microangiopathy (TMA)" and "Treatment and prognosis of Shiga toxin-producing Escherichia coli (STEC) hemolytic uremic syndrome in children" and "Immune TTP: Initial treatment".)

•Autoimmune mediated anemia and thrombocytopenia (Evan syndrome) – These patients have clinical findings of weakness, fatigue, acute onset of pallor, jaundice, icterus, and painless dark urine. The direct Coomb3s test is usually positive in these children. (See "Autoimmune hemolytic anemia (AIHA) in children: Classification, clinical features, and diagnosis".)

•Anemia secondary to bleeding due to severe immune thrombocytopenia (ITP) – In children with ITP, CBC parameters are typically normal. However, anemia may also be present if the child has severe thrombocytopenia with bleeding. (See "Immune thrombocytopenia (ITP) in children: Clinical features and diagnosis".)

●Severe thrombocytopenia (normal PT and aPTT) – ITP and other causes of pediatric thrombocytopenia can occasionally present with severe thrombocytopenia (platelet count <20,000/mm³), petechiae, ecchymoses, spontaneous bleeding, and anemia with ill appearance caused by intracranial and/or abdominal hemorrhage. (See "Approach to the child with unexplained thrombocytopenia" and "Immune thrombocytopenia (ITP) in children: Clinical features and diagnosis" and "Immune thrombocytopenia (ITP) in children: Initial management".)

Other rare but important causes of severe thrombocytopenia include hemolytic uremic syndrome (HUS) and thrombocytopenic purpura (TTP). HUS is characterized by the triad of thrombocytopenia, microangiopathic anemia, and acute kidney injury. TTP has a similar presentation but is uncommon in children. (See "Diagnostic approach to suspected TTP, HUS, or other thrombotic microangiopathy (TMA)" and "Treatment and prognosis of Shiga toxin-producing Escherichia coli (STEC) hemolytic uremic syndrome in children" and "Immune TTP: Initial treatment".)

●Pancytopenia – Pancytopenia is a presenting feature of bone marrow infiltration/malignancy. Less commonly, it may point to acquired or congenital bone marrow failure with aplastic anemia. (See "Treatment of acquired aplastic anemia in children and adolescents", section on 'Diagnosis'.)

●Isolated neutropenia – In children with sepsis, isolated neutropenia is most commonly acquired and post-infectious or drug-induced. The clinical findings that require a more comprehensive evaluation for underlying collagen vascular, nutritional/metabolic, immunodeficiency, or genetic abnormalities are provided in the algorithm (algorithm 3) and discussed in detail separately. (See "Overview of neutropenia in children and adolescents".)

●Prolonged PT and PTT (normal platelet count) – Purpuric skin lesions (petechiae, purpura, and/or ecchymoses) may arise from clotting factor deficiencies caused by liver disease or vitamin K deficiency. The PT is generally prolonged out of proportion compared to the PTT in liver disease and vitamin K deficiency. In children, vitamin K deficiency may present as vitamin-K deficient bleeding in newborns and young infants (hemorrhagic disease of the newborn) or severe poisoning after ingestion of warfarin or long-acting superwarfarin rat poisons (eg, brodifacoum). (See "Anticoagulant rodenticide poisoning: Clinical manifestations and diagnostic evaluation" and "Overview of vitamin K", section on 'Vitamin K-deficient bleeding in newborns and young infants'.)

Well-appearing — Despite well appearance, children with purpuric skin lesions require careful evaluation for signs of early sepsis or critical disorders of hemostasis.

Laboratory studies — For children with purpuric skin lesions that raise concern for a serious underlying cause, initial screening tests include [4]:

●Complete blood count (CBC) with a platelet count and peripheral smear

●Prothrombin time (PT) with an international normalized ratio (INR)

●Activated partial thromboplastin time (aPTT)

In these patients, results from the screening tests may suggest other important underlying etiologies that warrant further evaluation and management as directed by a pediatric hematologist/oncologist as described above for ill-appearing children with purpuric skin lesions. (See 'Interpretation' above.)

Febrile — Well-appearing children with fever and petechiae require laboratory studies, close monitoring, and frequent re-evaluation for early signs of sepsis or septic shock, as provided in the algorithm (algorithm 2). Febrile patients who develop signs of shock with progression of petechiae or development of purpura also require rapid treatment for sepsis (algorithm 1) and may require blood replacement products for management of disseminated intravascular coagulopathy. (See "Disseminated intravascular coagulation in infants and children", section on 'Management'.)

Afebrile — The diagnostic approach to afebrile, well-appearing children with petechiae includes a careful history and physical examination, evaluation of the type of purpuric lesion, distribution, and suspected underlying cause:

●Purpura – Well-appearing children with purpura warrant screening laboratory studies and close observation. IgA vasculitis (Henoch-Schönlein purpura [HSP]) and early sepsis are important conditions to consider in patients with this presentation.

●Petechiae or ecchymoses localized to a site of trauma – Unintentional trauma is the most common cause. The clinician should also assess for petechiae or bruising in a pattern or associated with other red-flag findings of physical child abuse (table 1).

●Petechiae above the nipple line (superior vena cava distribution) – This finding often reflects mechanical disruption of small veins and capillaries and is typically secondary to coughing or vomiting in children with a normal CBC and peripheral smear, PT/INR, and aPTT.

●Generalized petechiae or excessive ecchymosis at sites of unintentional trauma – These patients warrant screening laboratory studies and additional consultation and evaluation depending upon laboratory results:

•Thrombocytopenia – Children with severe, isolated thrombocytopenia (PT, aPTT normal) who are well-appearing and previously healthy with physical exam abnormalities consisting solely of petechiae and/or ecchymoses (picture 10 and picture 11) usually have immune-mediated thrombocytopenia (ITP) and warrant consultation with a pediatric hematologist. (See "Immune thrombocytopenia (ITP) in children: Clinical features and diagnosis".)

Other causes of thrombocytopenia are suggested by the clinical setting (see "Purpuric skin lesions (petechiae, purpura, and ecchymoses) in children: Causes"):

-Young infants with thrombocytopenia may have an inherited thrombocytopenia or alloimmune thrombocytopenia due to maternal antibodies.

-Patients with thrombocytopenia and other abnormalities on CBC (eg, anemia, leukopenia) may have malignancy (leukemia, neuroblastoma), bone marrow failure (congenital or acquired), hemolytic-uremic syndrome (HUS), or thrombotic thrombocytopenic purpura (TTP), or Evan syndrome.

-Children with thrombocytopenia and evidence for microangiopathic hemolytic anemia (eg, schistocytes on peripheral blood smear) may have HUS or TTP.

•Normal platelet count, abnormal PT or aPTT – Patients with purpura and abnormal initial coagulation tests require further investigation to determine the etiology of the abnormal PT or aPTT. (See "Clinical use of coagulation tests" and "Approach to the child with bleeding symptoms", section on 'Initial laboratory evaluation'.)

•Normal platelet count, PT, and aPTT – Children in whom trauma (unintentional or intentional) is the primary etiology of purpura will have normal screening tests in the absence of massive hemorrhage or transfusion. Petechiae are unusual as a primary presentation of trauma except in traumatic asphyxia. These screening tests are also usually normal in patients with vascular causes of purpura. (See "Physical child abuse: Recognition", section on 'Inflicted bruises'.)

In addition, some patients with von Willebrand disease or platelet function disorders will have normal screening tests. Further laboratory studies (platelet aggregation testing and von Willebrand testing) is often necessary to diagnose these conditions. (See "Clinical presentation and diagnosis of von Willebrand disease" and "Inherited platelet function disorders (IPFDs)".)

SUMMARY AND RECOMMENDATIONS

●Terminology and causes – Purpuric skin lesions and their general causes include (see 'Terminology' above):

•Petechiae – Petechiae are pinpoint to 1 to 2 mm non-blanching red to purple macules on the skin (picture 1). Infection and thrombocytopenia are important causes. They may also occur after localized trauma.

•Purpura – Purpura are larger, non-blanchable dark red to dark purple macules, papules, patches, or plaques that may occur on the skin or mucous membranes (picture 2A-B and picture 3 and picture 4). Causes include infection, systemic vasculitis, thrombocytopenia, or coagulation disorders.

•Ecchymoses (bruises) – Ecchymoses reflect larger extravasations of blood (hematoma or larger confluent purpura). They happen with direct trauma, coagulation disorders, or, less commonly, severe thrombocytopenia.

Darker skin pigmentation can reduce the visibility of purpuric skin lesions. For petechiae and purpura, lack of blanching is often best appreciated by diascopy (use of a clear glass slide or drinking glass to apply pressure to the skin).

●Evaluation – The patient's age, sex, clinical presentation, past medical history, family history, and physical examination usually determine the most likely cause for purpuric skin lesions.

When skin findings are not explained by a serious infection or trauma, the site and kind of purpura or bleeding often help establish the type of bleeding disorder (thrombocytopenia or platelet function disorder versus clotting factor deficiency or inhibition) (table 2). (See 'Evaluation' above.)

●Diagnostic approach – The extent and pace of diagnostic testing depends upon the general appearance of the patient, the presenting vital signs, and the predominant type of purpuric skin lesions (see 'Initial stabilization' above):

•Ill-appearing – Ill-appearing febrile or afebrile children with petechiae or purpura require emergency resuscitation for presumptive sepsis/septic shock with DIC, empiric antimicrobial agents (algorithm 1), and blood replacement products, as needed. (See "Septic shock in children in resource-abundant settings: Rapid recognition and initial resuscitation (first hour)" and "Disseminated intravascular coagulation in infants and children", section on 'Management'.)

Less common but important causes of ill appearance include hemolytic uremic syndrome (HUS) and, in infants and young children, thrombocytopenic purpura (TTP). These patients will have clinical and laboratory features of intravascular hemolysis/hemolytic anemia. (See 'Laboratory studies' above and "Overview of hemolytic anemias in children", section on 'Diagnostic approach'.)

Rarely, clotting factor deficiencies are caused by liver disease or vitamin K deficiency with severe bleeding and purpuric skin lesions. (See 'Ill-appearing' above.)

Children with suspicious ecchymoses (bruising) and/or other red-flag clinical manifestations of child abuse (table 1) require trauma resuscitation, further diagnostic evaluation in consultation with a multidisciplinary child abuse team, and notification of Child Protective Services as discussed separately:

-(See "Trauma management: Approach to the unstable child" and "Severe traumatic brain injury (TBI) in children: Initial evaluation and management".)

-(See "Physical child abuse: Diagnostic evaluation and management" and "Child abuse: Social and medicolegal issues".)

•Well-appearing – A well-appearing child with petechiae and or purpura and normal vital signs can be approached with less urgency but still requires timely evaluation to identify the underlying cause. These patients may also have infection, serious hematologic illness, or unrecognized child abuse.

Well-appearing children with fever and petechiae require laboratory studies, close monitoring, and frequent re-evaluation for early signs of sepsis or septic shock (algorithm 2). (See 'Well-appearing' above and 'Febrile' above.)

For afebrile children with purpuric skin lesions that raise concern for a serious underlying cause, initial screening tests include (see 'Afebrile' above):

-Complete blood count (CBC) with a platelet count and peripheral smear

-Prothrombin time (PT) with an international normalized ratio (INR)

-Activated partial thromboplastin time (aPTT

Consultation with a pediatric hematologist/oncologist is advised for patients with:

-Pancytopenia or thrombocytopenia and anemia

-Isolated thrombocytopenia

-Prolonged PT, PTT, or both

-Evidence of intravascular hemolysis or hemolytic anemia

In patients with a suspected bleeding disorder, additional studies should be obtained based upon the results of the initial screening tests and the clinical setting as provided in the table (table 4) and discussed separately. (See "Approach to the child with bleeding symptoms".)