What could be causing my symptoms of headache, nausea, and congestion, considering I have a history of allergies, sinusitis, and migraines?

Diagnostic Approach to Headache, Nausea, and Congestion

Given your history of allergies, sinusitis, and migraines, your symptoms most likely represent migraine rather than acute bacterial sinusitis, and you should be evaluated using validated migraine screening tools before pursuing sinus-directed treatment. 1

Why This Is Probably Migraine, Not Sinusitis

The combination of headache, nausea, and congestion strongly suggests migraine rather than bacterial sinusitis. 1, 2 Here's the critical reasoning:

• Nasal congestion occurs in migraine due to vasodilation of the nasal mucosa as part of the vascular event itself, not from sinus infection 3, 2
• Up to 90% of self-diagnosed "sinus headaches" are actually migraines 2
• Nausea is a hallmark migraine symptom but is NOT typical of sinusitis 1
• Chronic and recurring headaches with migraine features are not due to sinus disease 4, 5

When to Suspect Actual Bacterial Sinusitis Instead

You should only consider acute bacterial sinusitis if you have these specific features:

• Persistent purulent (thick, colored) nasal discharge lasting >10-14 days without improvement 1, 6
• Concurrent high fever (>102°F) AND purulent discharge from symptom onset 6
• Unilateral facial/dental pain with tenderness over a specific sinus 1
• Recent viral upper respiratory infection followed by worsening symptoms 3

The absence of fever and purulent discharge makes bacterial sinusitis unlikely. 6, 3

Immediate Diagnostic Steps

Use Validated Migraine Screening

Complete the ID-Migraine questionnaire (3 questions) or Migraine Screen Questionnaire (5 questions), which have sensitivities of 81-93% and positive predictive values of 83-93% 1:

• Do you experience photophobia (light sensitivity)?
• Do you experience nausea with headaches?
• Has headache limited your activities for ≥1 day in the last 3 months?

Physical Examination Findings to Assess

Look for these specific signs that differentiate the conditions 1:

• Migraine indicators: Photophobia, phonophobia, unilateral throbbing pain aggravated by activity 1
• Sinusitis indicators: Purulent nasal discharge visible on examination, maxillary tooth pain, unilateral sinus tenderness, fever 1, 6
• Allergic rhinitis indicators: Clear nasal discharge, nasal/ocular itching, sneezing, pale/boggy turbinates 6

Red Flags Requiring Urgent Evaluation

Seek immediate evaluation if you develop any of these warning signs 1:

• Thunderclap headache (sudden, severe onset)
• Fever with altered mental status or neck stiffness
• Visual changes, double vision, or eye pain/swelling
• Focal neurological symptoms
• Severe headache different from your usual pattern

These red flags warrant neuroimaging (MRI preferred over CT) or lumbar puncture to exclude life-threatening secondary causes like meningitis or subarachnoid hemorrhage. 1

Treatment Approach Based on Diagnosis

If Migraine Is Confirmed (Most Likely)

Treat as migraine with appropriate acute and preventive therapy rather than pursuing sinus-directed treatment. 1, 2 The congestion will resolve when the migraine is properly managed 3, 2.

If Acute Bacterial Sinusitis Is Suspected

Only pursue antibiotic therapy if you have purulent discharge on examination plus persistent symptoms >10-14 days 6, 7:

• First-line treatment: Amoxicillin 500mg three times daily for 7-10 days 6
• Adjunctive therapy: Intranasal corticosteroids, saline irrigation, analgesics 6, 7
• Follow-up in 3-5 days; switch to amoxicillin-clavulanate if no improvement 6

If Chronic Rhinosinusitis (Symptoms >8 Weeks)

Chronic sinusitis is primarily inflammatory, not infectious, and does NOT typically cause headache 7, 3:

• Start fluticasone propionate nasal spray 200mcg daily 7
• Add daily saline irrigation 7
• Do NOT use antibiotics unless purulent discharge is present on examination 7
• Refer to ENT if symptoms persist after 4 weeks of medical therapy 7

Common Pitfalls to Avoid

Do NOT obtain CT or MRI imaging to distinguish bacterial sinusitis from viral infection in typical presentations 6 - imaging is only indicated when symptoms persist despite appropriate medical therapy or when red flags are present 1, 7.

Do NOT assume that pain over the sinuses means sinus disease 3, 8 - frontal head pain is far more commonly caused by migraine or tension-type headache 8.

Do NOT add antihistamines for acute bacterial sinusitis 7 - they provide no additive benefit over standard treatment.