What are the possible causes of ecchymoses in children?

Causes of Ecchymoses in Children

Ecchymoses in children arise from bleeding disorders, trauma (including abuse), dermatologic conditions, nutritional deficiencies, connective tissue disorders, and systemic diseases—each requiring specific diagnostic evaluation based on age, bruising location, and associated symptoms.

Age-Specific Patterns and Red Flags

Infants (≤9 months)

• Any bruising in non-mobile infants warrants immediate evaluation for both abuse and underlying bleeding disorders, as bruising is extremely uncommon before independent mobility 1
• Infants younger than 6 months with unexplained bruising require prompt work-up regardless of location 2
• Head and face injuries predominate in this age group when abuse is present 3
• Vitamin K deficiency is particularly important in infants who haven't received prophylaxis at birth, presenting with prolonged PT 1

Young Children (10 months - prepubertal)

• Bruises on soft-tissue areas (thighs, upper arms, trunk) are more suggestive of bleeding disorders than bruises over bony prominences from normal activity 1, 4
• Bruising on buttocks, ears, genitals, or patterned bruising has higher specificity for abuse 4
• Seat-belt ecchymoses in restrained passengers indicate potential internal injury, with 81% of such cases involving major intestinal injuries 5

Dermatologic Conditions

Lichen Sclerosus

• Ecchymosis may be very striking in prepubertal girls with anogenital lichen sclerosus and can be potentially mistaken as evidence of sexual abuse 6
• Typical lesions are porcelain-white papules and plaques with areas of ecchymosis in the interlabial sulci, labia minora, and perineal body 6
• Perianal involvement occurs in 30% of female cases, often presenting with constipation due to painful fissuring 6
• However, lichen sclerosus and sexual abuse are not mutually exclusive, as lichen sclerosus exhibits the Koebner phenomenon at trauma sites 6
• Suspicious features include lichen sclerosus in older prepubertal girls, poor response to treatment, presence of sexually transmitted infections, or other signs of abuse 6

Bleeding and Hemostatic Disorders

Inherited Bleeding Disorders

• Von Willebrand disease is the most common inherited bleeding disorder (≈1 in 1,000 individuals), presenting with easy bruising and mucocutaneous bleeding, yet it is NOT detected by routine PT/aPTT screening 2, 1
• Hemophilia (Factor VIII or IX deficiency) causes significant bruising even with mild deficiencies, particularly in males 1
• Factor XIII deficiency produces substantial bruising despite normal PT/aPTT results, requiring a specific Factor XIII activity assay 2, 1
• Platelet function disorders show normal platelet counts but abnormal aggregation, requiring specialized platelet aggregation studies 2, 1

Acquired Bleeding Disorders

• Immune thrombocytopenia (ITP) is a transient, often self-resolving disorder characterized by low platelet count 1
• Disseminated intravascular coagulation (DIC) may produce any type of bruising or bleeding, including severe intracranial hemorrhage 2, 1

Nutritional Deficiencies

• Vitamin K deficiency leads to prolonged PT (and sometimes aPTT), especially in infants lacking prophylaxis 2, 1
• Scurvy (vitamin C deficiency) manifests with bruising and bleeding due to impaired collagen synthesis, producing follicular hyperkeratosis and perifollicular hemorrhages 2, 7
• Severe malnutrition can cause extensive ecchymoses on lower extremities with decreased levels of vitamins C, K, B12, and E 7

Connective Tissue and Vascular Disorders

• Ehlers-Danlos syndrome predisposes to easy bruising through vascular fragility and connective-tissue abnormalities 2, 4
• Arteriovenous malformations can cause localized bleeding and bruising 1
• Senile purpura results from age-related thinning of blood vessels and skin (relevant in elderly, not typical in children) 2, 1

Systemic Medical Conditions

• Chronic liver disease or cirrhosis reduces synthesis of clotting factors, resulting in spontaneous bruising 2, 1
• Malignancies and infiltrative disorders can cause thrombocytopenia or coagulation abnormalities 2, 1
• Constitutional symptoms such as fever, unexplained weight loss, or night sweats may signal malignancy 4

Diagnostic Approach

History Assessment

• Inquire about significant bleeding after surgery, dental procedures, epistaxis requiring intervention, or joint hemorrhages 4
• Document all medications including NSAIDs, anticoagulants, antiplatelets, steroids, and herbal supplements (ginkgo biloba, fish oil, garlic) that affect bleeding 1, 4
• Obtain family history of bleeding disorders, particularly von Willebrand disease 4
• Assess trauma history to determine if bruising pattern is explained by reported mechanism 4
• Evaluate developmental capabilities to determine if bruising location is consistent with normal activity 4

Physical Examination

• Diffuse abdominal tenderness in children with seat-belt ecchymoses indicates major intestinal injury in 84% of cases 5
• Examine for signs of lichen sclerosus: porcelain-white papules/plaques with ecchymosis in anogenital region 6
• Look for connective tissue signs: skin hyperextensibility or fragility suggesting Ehlers-Danlos syndrome 4
• Assess for systemic illness indicators 4

Laboratory Testing

• Initial screening: CBC with platelet count, peripheral blood smear, PT, aPTT, and fibrinogen level if PT or aPTT are abnormal 1, 4
• Critical limitation: PT and aPTT do NOT reliably detect von Willebrand disease or Factor XIII deficiency 2, 1, 4
• For suspected von Willebrand disease: obtain VWF antigen, VWF ristocetin cofactor activity, and Factor VIII coagulant activity 1, 4
• Platelet function testing (e.g., PFA-100) can screen for platelet disorders but requires hematology consultation for interpretation 4

Referral Indications

• Hematology referral when specialized testing (platelet function studies, von Willebrand multimer analysis, Factor XIII assay) is needed or initial laboratory results are abnormal 2, 4
• Children with intracranial hemorrhage concerning for abuse require evaluation for bleeding disorders, though laboratory findings suggestive of a bleeding disorder do not eliminate abuse from consideration 1, 4

Common Pitfalls

• Assuming normal PT/aPTT rules out bleeding disorders is incorrect—these tests miss von Willebrand disease, Factor XIII deficiency, and platelet function disorders 1, 4
• Overlooking mild hemophilia, as mild Factor VIII or IX deficiency can cause significant bleeding even with normal aPTT 1, 4
• Failing to recognize that lichen sclerosus and sexual abuse can coexist through Koebnerization 6
• Performing extensive testing without clinical indication, as extreme rarity of some bleeding disorders makes universal screening unreasonable 4
• Inappropriate specimen handling commonly leads to false-positive coagulation results; testing should be performed in experienced laboratories 1