Correct Answer: A. Medication overuse headache
Medication overuse headache (MOH) is a secondary headache disorder triggered by regular, excessive use of analgesics, triptans, ergots, or combination analgesics. The diagnostic hallmark is the temporal relationship between drug overuse and headache escalation, combined with improvement upon drug withdrawal. This patient presents the classic triad: (1) chronic headache for ≥6 months, (2) regular analgesic use, and (3) acute worsening that resolves within 72 hours of stopping the medication. According to ICHD-3 criteria, MOH is diagnosed when headache occurs on ≥15 days/month in a patient taking acute medication ≥10–15 days/month (depending on drug class) for >3 months, with improvement after withdrawal. The pathophysiology involves central sensitization and altered pain modulation from chronic medication exposure. In Indian clinical practice, MOH is increasingly common due to over-the-counter availability of analgesics and combination drugs (paracetamol + aspirin + caffeine). The key discriminator here is the rapid improvement upon cessation—this is pathognomonic for MOH and distinguishes it from primary headache disorders, which persist regardless of medication changes.
Why the other options are wrong
B. Cluster headache — Cluster headache presents with unilateral orbital pain, autonomic features (lacrimation, nasal congestion, ptosis), and episodic patterns (weeks to months of daily attacks followed by remission). It does NOT respond to simple analgesics and is NOT triggered by medication overuse. The patient's 6-month continuous course and analgesic responsiveness rule out cluster headache entirely. C. Tension headache — Tension headache is bilateral, pressing, non-pulsatile, and typically mild-to-moderate in severity. Critically, it does NOT improve with analgesic withdrawal—in fact, patients with chronic tension headache often require ongoing medication management. The acute worsening followed by rapid improvement upon stopping medication is incompatible with primary tension headache pathophysiology. D. Chronic migraine — Chronic migraine involves ≥15 headache days/month for ≥3 months with migraine features (unilateral, pulsatile, nausea, photophobia). However, chronic migraine persists despite medication withdrawal and often requires preventive therapy (propranolol, amitriptyline). The resolution of headache within days of stopping analgesics is inconsistent with chronic migraine, which would continue or worsen without proper prophylaxis.
High-Yield Facts
- MOH diagnostic threshold: ≥15 headache days/month + acute medication use ≥10–15 days/month for >3 months (ICHD-3).
- Medication classes implicated: Simple analgesics (paracetamol, aspirin), NSAIDs, triptans, ergots, and combination analgesics—all carry equal risk in India.
- Withdrawal headache: Typically peaks 24–48 hours after stopping medication, then resolves within 7 days; this temporal pattern is diagnostic.
- Rebound vs. MOH: Rebound is acute worsening during overuse; MOH is the chronic state that improves only after prolonged withdrawal.
- Indian context: Over-the-counter fixed-dose combinations (paracetamol + aspirin + caffeine) are major culprits; patient education on safe analgesic use is critical.
Mnemonics
MOH = Medication + Overuse + Headache (temporal triad) Medication overuse (≥10–15 days/month) → Overuse headache (≥15 days/month) → Headache improves on Withdrawal. Use this to remember: the diagnosis requires BOTH chronic overuse AND improvement with cessation. ICHD-3 MOH Rule: 3-10-15 3 months of overuse, 10–15 days/month of acute medication (varies by class), 15 headache days/month. Rapid recall for exam: if all three numbers align, think MOH.
NBE Trap
NBE often pairs MOH with chronic migraine or tension headache to test whether students recognize that primary headaches persist despite medication changes, whereas MOH uniquely improves upon withdrawal. The trap is selecting "chronic migraine" if the student forgets that migraine requires preventive therapy and does not resolve by simply stopping analgesics.
Clinical Pearl
In Indian outpatient practice, MOH is frequently missed because patients self-medicate with over-the-counter analgesics and never report the medication history unless directly asked. A simple rule: any patient with chronic daily headache + regular analgesic use should be counseled on medication withdrawal first, before escalating to imaging or preventive therapy. This approach saves cost and often resolves the headache within a week.
_Reference: Harrison Ch. 424 (Headache); ICHD-3 Diagnostic Criteria for Medication Overuse Headache_