Imagine this: A patient strolls into the OPD with fatigue, joint pain, and a malar rash — and your rheumatology reflexes scream Systemic lupus erythematosus. But then comes the twist: they’re not your classic ANA-positive, anti-dsDNA warrior. Instead, their labs shout anti-histone.
And the real culprit? A prescription pad. 💊
Welcome to the dramatic but reversible world of Drug-Induced Lupus (DIL). To remember the usual suspects, here’s a mnemonic that’s got legs:
“My Two HIPS” – because these drugs will trip up your immune system and your diagnostic confidence.
🧠 Mnemonic Table: My Two HIPS
| Letter | Drug | Commentary / Clinical Notes |
|---|---|---|
| My | Methyldopa | Alpha-2 agonist – old-school antihypertensive with new-age drama 🧓🏼💉 |
| Two | TNF-α inhibitors | Etanercept, infliximab – autoimmune double agents 🎭 |
| H | Hydralazine | Most classic offender – watch out in slow acetylators 🚧 |
| I | Isoniazid | TB treatment that sometimes backfires on the immune system 🦠💥 |
| P | Procainamide/Phenytoin | Antiarrhythmic & antiepileptic – both mess with nuclear tolerance ⚡ |
| S | Sulfa drugs | From antibiotics to diuretics, this class loves to stir the pot 💊🥄 |
🏥 Real-Life Clinical Experiences from Quetta
At Sheikh Khalifa Bin Zayed Hospital, we had a patient on methyldopa for pregnancy-related hypertension.
She came in with joint pain, low-grade fever, and a “lupus-like” rash. The kicker? She had positive ANA, positive anti-histone, and no prior autoimmune history. Discontinued the methyldopa — and poof! The symptoms resolved faster than a junior doctor at 4:59 pm on a Friday. 😅
🔍 Key Clinical Clues in DIL:
- Anti-histone antibodies = hallmark of drug-induced lupus (especially when anti-dsDNA is negative).
- Symptoms: Arthralgia, fever, rash, serositis — but no renal or CNS involvement (unlike SLE).
- Resolution occurs after discontinuing the offending agent.
- Think of DIL when patients develop lupus-like symptoms after starting a chronic med.
📘 For USMLE, FCPS Part 1, PLAB & Ward Rounds
- Don’t just memorize drugs — understand which immune markers appear in drug-induced vs idiopathic SLE.
- In exams, if a TB patient gets lupus signs → think isoniazid.
- If your “autoimmune” patient is being treated for an autoimmune condition… and suddenly has more autoimmunity? Yep — TNF-α inhibitors.
📚 Written by:
Dr. Aurangzaib Qambrani
MBBS, PLAB, MRCP-UK
General Medicine, Gastroenterology & Cardiac Care Unit
Sheikh Khalifa Bin Zayed Hospital, Quetta
