What are the key clinical findings in a 25‑year‑old Filipino male presenting with severe headache and recurrent vertigo with nausea/vomiting for three days after a first high‑altitude trek four days ago?

Acute Mountain Sickness with Severe Headache and Vestibular Symptoms

This 25-year-old male presents with classic acute mountain sickness (AMS) following rapid ascent to high altitude, manifesting as severe headache with recurrent dizziness and vomiting that began 3 days after his first high-altitude trek.

Key Clinical Findings

Primary Diagnosis: Acute Mountain Sickness

• Severe headache is the cardinal symptom of AMS, occurring in response to hypobaric hypoxia at altitudes typically above 2,500 meters 1
• Recurrent dizziness relieved by vomiting represents the vestibular and gastrointestinal components of AMS, which commonly accompany the headache 1
• Timing is diagnostic: symptoms began 3 days after initial ascent (day 4 of exposure), which falls within the typical 6-72 hour window for AMS onset following rapid altitude gain 1
• First-time high-altitude exposure is a significant risk factor, as this patient had no prior acclimatization 1

Lake Louise Scoring Assessment

The patient should be systematically evaluated using the Lake Louise Scoring system 1:

• Headache: severe (score 3)
• Nausea/vomiting: present with multiple episodes (score 2-3)
• Dizziness: recurrent episodes (score 2)
• Fatigue: likely present given the severity of other symptoms

A total score ≥3 with headache confirms AMS 1

Critical Red Flags Requiring Urgent Evaluation

Rule Out High-Altitude Cerebral Edema (HACE)

Immediate neurologic examination is mandatory to exclude progression to HACE, which carries significant mortality risk 1:

• Assess for ataxia: inability to perform tandem gait or stand with feet together
• Evaluate mental status: confusion, altered consciousness, or behavioral changes
• Check for focal neurologic deficits: weakness, sensory loss, or cranial nerve abnormalities
• Examine for papilledema: fundoscopic examination for optic disc swelling

Distinguish from Posterior Circulation Stroke

While less likely given the altitude exposure history, stroke must be excluded in any patient with severe headache and dizziness 2, 3:

• The patient's age (25 years) and lack of vascular risk factors make stroke less probable
• However, severe postural instability with inability to stand or walk would mandate urgent MRI 2
• New severe headache reaching maximal intensity rapidly is a red flag requiring imaging 3

Additional High-Altitude Complications to Assess

High Altitude Retinopathy (HAR)

• Visual symptoms: ask specifically about blurred vision or visual field loss 1
• HAR occurs in most trekkers ascending beyond 4,900 meters and can cause retinal hemorrhages and optic disc swelling 1
• Fundoscopic examination should be performed if available to detect retinal changes 1

Dehydration and Electrolyte Disturbances

• Recurrent vomiting increases risk of dehydration, which exacerbates AMS severity 1
• Dehydration is a patient-specific factor that worsens the degree of high-altitude pathology 1

Immediate Management Priorities

Descent and Oxygen

• Immediate descent to lower altitude is the definitive treatment if symptoms are severe or progressive 1
• Supplemental oxygen should be administered to increase oxygen perfusion 1

Pharmacologic Intervention

• Acetazolamide can be used therapeutically (not just prophylactically) for AMS, though the patient should be monitored for transient myopic shift 1
• Dexamethasone is indicated for severe AMS or when descent is not immediately possible

Symptomatic Relief

• Antiemetics (metoclopramide or prochlorperazine) for severe vomiting
• Analgesics (NSAIDs or acetaminophen) for headache, avoiding opioids which can worsen hypoxemia

Common Diagnostic Pitfalls to Avoid

• Do not attribute all symptoms to AMS without neurologic examination: 75-80% of posterior circulation strokes present without focal deficits initially 2, 3
• Do not delay descent while waiting for diagnostic studies if HACE is suspected clinically 1
• Do not assume the patient is adequately hydrated: vomiting and high altitude both promote fluid loss 1
• Do not overlook medication history: if the patient took any prophylactic medications, side effects could contribute to symptoms 1

Disposition and Follow-Up

• If ataxia, altered mental status, or focal deficits are present: immediate evacuation to lower altitude and emergency department evaluation with MRI brain without contrast 2, 3
• If symptoms are moderate AMS without HACE features: descent of 500-1,000 meters, rest, hydration, and pharmacologic treatment 1
• Reassess within 12-24 hours: symptoms should improve with descent and treatment; worsening mandates further descent and possible imaging 1