What are the common causes of bilateral subconjunctival hemorrhage?

Bilateral Subconjunctival Hemorrhage: Common Causes

Bilateral subconjunctival hemorrhage most commonly results from viral conjunctivitis (particularly adenoviral), systemic anticoagulation, severe Valsalva maneuvers, or underlying bleeding disorders—with viral infection being the most frequent cause in clinical practice. 1

Primary Etiologies

Infectious Causes (Most Common)

• Viral conjunctivitis is the leading cause, with adenoviral infection characteristically producing petechial and subconjunctival hemorrhages that often begin unilaterally but become sequentially bilateral within days 2, 1
• Epstein-Barr virus presents with hemorrhagic conjunctivitis including bilateral subconjunctival hemorrhage and periorbital edema 1
• Measles (rubeola) causes bilateral subconjunctival hemorrhages along with other conjunctival findings 1
• Acute conjunctivitis of any etiology frequently presents with subconjunctival hemorrhage as a distinctive sign 2, 1

Medication-Related Causes

• Anticoagulation therapy (warfarin, direct oral anticoagulants) is a well-established medication-related cause 1
• Recurrent, bilateral, and severe conjunctival hemorrhages in patients on oral anticoagulation mandate evaluation of prothrombin time and coagulation parameters 3

Systemic Vascular Causes

• Systemic hypertension is a common cause, particularly in older patients 4
• Diabetes and arteriosclerosis are more prevalent risk factors among elderly patients 5

Mechanical Causes

• Severe or repetitive Valsalva maneuvers from prolonged vomiting or coughing spells can produce bilateral hemorrhages 3
• Minor local trauma, though more commonly unilateral, can occasionally be bilateral 4

Red Flags Requiring Further Investigation

When to Pursue Extensive Workup

• Recurrent or persistent bilateral subconjunctival hemorrhage without identifiable cause warrants further investigation 1, 5
• Hemorrhages associated with conjunctival nodules or masses require biopsy to exclude malignancy 1

Malignancies to Consider

• Ocular adnexal lymphoma may initially present as recurrent subconjunctival hemorrhage with a characteristic salmon-pink conjunctival lesion 1, 6
• Sebaceous carcinoma can appear with yellowish discoloration and subconjunctival multilobulated yellow mass 1
• Conjunctival melanoma presents as painless brown or fleshy-pink lesions 1

Hematologic Evaluation

• Blood dyscrasias and clotting disorders should be investigated in cases of recurrent, bilateral, severe hemorrhages 3
• However, the prevalence of hemostatic abnormalities in patients with recurrent spontaneous subconjunctival hemorrhage is not significantly different from the general population 7
• Routine hemostatic screening or second-level coagulation tests are not indicated for isolated recurrent subconjunctival hemorrhage without other bleeding manifestations 7

Diagnostic Algorithm

Initial Assessment

• Check blood pressure in all patients, particularly those over 50 years of age 4, 5
• Obtain medication history focusing on anticoagulants, antiplatelet agents, and NSAIDs 1, 7
• Assess for recent viral illness, upper respiratory infection, or exposure to infected contacts 2, 1
• Inquire about recent severe coughing, vomiting, or straining episodes 3

Physical Examination

• Examine for conjunctival injection, watery discharge, follicular reaction, and preauricular lymphadenopathy suggesting viral etiology 2
• Inspect carefully for conjunctival masses, nodules, or salmon-pink lesions that would mandate biopsy 1, 6
• Perform fluorescein staining to detect corneal involvement 2

When to Escalate Care

• Immediate ophthalmology referral for associated conjunctival masses or nodules 1
• Further workup including bleeding disorder evaluation only if hemorrhages are severe, recurrent, and accompanied by other bleeding manifestations 7, 5
• Systemic evaluation for hypertension, diabetes, and vascular disease in elderly patients with recurrent episodes 4, 5

Common Pitfalls

• Assuming hemostatic disorders are common: The prevalence of coagulation abnormalities in isolated recurrent subconjunctival hemorrhage is no higher than in the general population; extensive hematologic workup is unnecessary without other bleeding symptoms 7
• Missing underlying malignancy: Persistent or recurrent hemorrhage with conjunctival lesions requires biopsy, as lymphoma can present initially with subconjunctival hemorrhage 1, 6
• Overlooking medication effects: Always review anticoagulation therapy and check coagulation parameters in patients on warfarin or other anticoagulants 1, 3
• Failing to check blood pressure: Hypertension is a major risk factor, especially in older patients, and should be assessed in every case 4, 5