Adult with acute gastritis, ongoing headache evaluation, and bilateral conjunctival injection—what are the likely etiologies and recommended work‑up and treatment?

Acute Gastritis with Bilateral Conjunctival Injection and Headache: Diagnostic Approach and Management

Immediate Clinical Assessment

This presentation requires urgent evaluation for systemic infectious or inflammatory conditions that can simultaneously affect the gastrointestinal tract, eyes, and central nervous system, with particular attention to viral syndromes, bacterial infections, and medication-related toxicity.

The combination of acute gastritis, bilateral red eyes (conjunctival injection), and headache suggests several important diagnostic possibilities that must be systematically evaluated:

Primary Differential Diagnoses

Viral Syndromes with Multi-System Involvement:

• Epstein-Barr virus (EBV) can present with follicular conjunctivitis (typically unilateral but can be bilateral), gastrointestinal symptoms, generalized fatigue, fever, pharyngitis, and lymphadenopathy 1
• COVID-19 (SARS-CoV-2) may cause conjunctival injection (unilateral more than bilateral), follicular reaction, chemosis, watery discharge, and can present with gastrointestinal symptoms and headache 1
• Measles (rubeola) presents with bilateral conjunctivitis, fever, cough, coryza, and gastrointestinal symptoms, though this is less common in vaccinated populations 1

Bacterial Infections:

• Parinaud oculoglandular syndrome (most commonly from Bartonella henselae/cat scratch disease) presents with unilateral granulomatous follicular conjunctivitis, ipsilateral lymphadenopathy, fever, and can have systemic symptoms 1
• Gonococcal infection can cause marked bilateral conjunctival injection with purulent discharge and may have systemic manifestations including gastrointestinal symptoms 1

Medication or Toxin-Related:

• Acute hemorrhagic gastritis is frequently associated with NSAID use, alcohol abuse, or physiologic stress 2
• NSAIDs used for headache management can cause both gastritis and medication-induced conjunctivitis 1

Critical Red Flags Requiring Immediate Ophthalmology Referral

The following findings mandate urgent ophthalmology consultation 3:

• Visual loss or visual changes
• Moderate to severe eye pain (not relieved by topical anesthetics)
• Severe purulent discharge suggesting gonococcal infection
• Corneal involvement (infiltrate, ulcer, or opacity)
• Photophobia with pain suggesting keratitis or iritis
• Distorted pupil
• History of herpes simplex virus eye disease
• Immunocompromised status

Recommended Diagnostic Work-Up

Ocular Examination

• Visual acuity measurement in both eyes 3
• Slit-lamp biomicroscopy if available, or detailed examination with penlight looking for:
  • Pattern of conjunctival injection (diffuse vs. localized)
  • Discharge character (watery, mucopurulent, or purulent) 3
  • Follicular vs. papillary reaction 1
  • Corneal clarity and epithelial integrity 4
  • Pupillary reaction and anterior chamber examination 4
• Preauricular lymphadenopathy assessment 1

Systemic Evaluation

• Complete blood count with differential to assess for viral vs. bacterial infection
• Comprehensive metabolic panel to evaluate electrolyte disturbances from gastritis/vomiting
• Liver function tests if viral hepatitis or EBV suspected 1
• Conjunctival cultures if severe purulent discharge present, particularly to rule out gonococcal or chlamydial infection and MRSA 1, 3
• Blood cultures if febrile or systemically ill
• COVID-19 testing given current epidemiology 1
• Abdominal imaging (CT) if severe gastritis symptoms, to rule out complications like phlegmonous gastritis 5

Medication History Review

• Document all recent medications, particularly NSAIDs, aspirin, alcohol use, and any topical eye medications 1, 2
• Assess for preserved eye drops that can cause toxic conjunctivitis 6

Treatment Algorithm

For Conjunctivitis Management

If bacterial conjunctivitis suspected (mucopurulent discharge, matting of eyelids) 3:

• Apply broad-spectrum topical antibiotic such as bacitracin ophthalmic ointment directly into the conjunctival sac 1-3 times daily for 5-7 days 3
• Avoid indiscriminate use of topical antibiotics or corticosteroids for presumed viral conjunctivitis, as viral conjunctivitis will not respond to antibacterial agents 1

If gonococcal or chlamydial infection suspected (severe purulent discharge, sexual exposure history):

• Systemic antibiotics are required in addition to topical therapy 3
• Immediate ophthalmology referral for potential corneal involvement 1

If viral conjunctivitis suspected (watery discharge, follicular reaction, systemic viral symptoms):

• Supportive care with cool compresses and preservative-free artificial tears 1
• Educate about hand washing and avoiding sharing towels/pillows to prevent transmission 7
• Avoid close contact with others during contagion period 1

If medication-induced conjunctivitis suspected:

• Discontinue the offending agent (particularly NSAIDs or preserved eye drops) 1, 3
• Resolution typically occurs over weeks to months 1
• Consider preservative-free artificial tears 1

For Acute Gastritis Management

Immediate supportive measures 2:

• Discontinue NSAIDs, aspirin, and alcohol if these are contributing factors 2
• Initiate proton pump inhibitor therapy (e.g., omeprazole 40 mg daily or pantoprazole 40 mg daily)
• Consider H2-receptor antagonists as alternative
• Antiemetics if nausea/vomiting present (metoclopramide or ondansetron)
• IV fluid resuscitation if dehydrated from vomiting

If severe gastritis with systemic toxicity:

• Consider acute phlegmonous gastritis, which requires immediate broad-spectrum IV antibiotics and possible surgical intervention 5
• Obtain abdominal CT to assess for gastric wall thickening, edema, or gas 5

For Headache Management

Avoid NSAIDs given active gastritis 1, 2:

• Consider acetaminophen 650-1000 mg every 4-6 hours (maximum 4 g/day) 1
• If migraine suspected and severe, consider ketorolac 60 mg IM only after gastritis is controlled and bleeding risk assessed 1
• Avoid opioid analgesics for chronic headaches due to dependency and rebound risk 1

Follow-Up and Monitoring

Follow-up visits should include 3:

• Interval history focusing on symptom progression
• Visual acuity measurement
• Slit-lamp biomicroscopy or detailed eye examination
• Assessment of gastritis symptoms and medication tolerance

Frequency of follow-up depends on severity 1, 3:

• Mild conjunctivitis: 5-7 days
• Moderate conjunctivitis or gastritis: 2-3 days
• Severe symptoms or lack of improvement: 24-48 hours or immediate referral

Consider conjunctival cultures if symptoms persist despite appropriate therapy, particularly to rule out MRSA 3

Common Pitfalls to Avoid

• Do not prescribe topical corticosteroids without ophthalmology consultation, as they can worsen viral or bacterial keratitis and require IOP monitoring 1
• Do not assume simple viral conjunctivitis without ruling out serious systemic infections like gonococcal disease, EBV, or COVID-19 that require specific management 1
• Do not continue NSAIDs for headache in the setting of acute gastritis, as this worsens mucosal damage 2
• Do not delay ophthalmology referral if any red flag signs present, as conditions like gonococcal conjunctivitis can rapidly progress to corneal perforation 1
• Do not overlook medication-induced causes by failing to obtain complete medication history including over-the-counter NSAIDs and eye drops 1, 6