What are the common causes of subconjunctival hematoma?

Common Causes of Subconjunctival Hemorrhage

The most common causes of subconjunctival hemorrhage are minor local trauma, systemic hypertension, and acute conjunctivitis, with trauma being more frequent in younger patients and hypertension predominating in older individuals. 1

Primary Etiologies by Age Group

Younger Patients

• Trauma is the leading cause, particularly minor local trauma, with increased frequency during summer months 1
• Contact lens usage represents a significant risk factor in this demographic 2
• Traumatic subconjunctival hemorrhage typically presents as localized hemorrhage in the temporal areas 3

Older Patients

• Systemic hypertension is the predominant cause and should be specifically evaluated 1, 2
• Diabetes mellitus is a common associated condition 2, 3
• Arteriosclerosis contributes to vessel fragility 2
• The extent of hemorrhage shows an age-related increase, with older patients demonstrating more extensive involvement 3

Additional Common Causes

Infectious/Inflammatory

• Acute conjunctivitis, particularly viral conjunctivitis, frequently presents with petechial and subconjunctival hemorrhage 4, 1
• Adenoviral conjunctivitis can cause distinctive subconjunctival hemorrhage patterns 4

Medication-Related

• Anticoagulation therapy (warfarin, direct oral anticoagulants) 5, 2
• Antiplatelet agents (aspirin, clopidogrel) 2
• NSAIDs 2

Critical Red Flags Requiring Further Investigation

For recurrent or persistent subconjunctival hemorrhage, systematic workup is mandatory to exclude serious underlying pathology. 5, 2

Hematologic Disorders

• Bleeding disorders should be investigated in recurrent cases, though prevalence is not significantly higher than the general population 6, 2
• Acute leukemia can present with massive bilateral spontaneous subconjunctival hemorrhage 7
• Von Willebrand disease is rarely identified (approximately 1% prevalence) 6

Malignancies

• Ocular adnexal lymphoma may initially present as recurrent subconjunctival hemorrhage with a characteristic salmon-pink conjunctival lesion 5
• Sebaceous carcinoma can appear as yellowish discoloration with subconjunctival multilobulated yellow mass 4, 8
• Conjunctival melanoma presents as painless brown or fleshy-pink lesions 4, 8

Clinical Pitfalls to Avoid

• Always measure blood pressure in patients with subconjunctival hemorrhage, particularly in older individuals 1
• Look for salmon-pink lesions in the conjunctiva, which suggest possible lymphoma rather than benign hemorrhage 5
• Evaluate for bilateral or massive hemorrhage, which may indicate blood dyscrasia or leukemia 7
• Assess hemorrhage location and extent: inferior areas are most commonly affected in benign cases, while temporal involvement may suggest trauma or diabetes 3
• Do not routinely order hemostatic screening for isolated subconjunctival hemorrhage, as prevalence of abnormalities is not different from the general population 6

When to Investigate Further

Workup is warranted when hemorrhage is:

• Recurrent without identifiable cause 5, 2
• Bilateral and massive 7
• Associated with conjunctival nodules or masses requiring biopsy 5, 8
• Accompanied by systemic symptoms suggesting bleeding disorder or malignancy 2, 7