Twelve cases with lupus somewhere in the story and one defensible diagnosis each. The original connective-tissue mimics now share the page with noisy everyday presentations involving a Thanksgiving meal, wine and Netflix, two cats, a truck-stop tonic, a postpartum symptom search, sports gear, and a workout challenge. The model must diagnose each case and name both the decisive finding and the decoy.
UNVALIDATED v2.0. v1.0 was shaken down against Claude Fable 5.1 and scored 6/6 on isSle; that result does not validate the six added cases or the new decoy field. Run a fresh single-model shakedown before a recorded lineup.
The answer key is challenge-defs/assets/its-never-lupus.json. Each vignette retains a forcing finding specific enough to close the case. Difficulty comes from asking for more and from separating decisive evidence from memorable but irrelevant context, not from making the diagnosis arguable.
Mechanical fields. Twelve rows in order. isSle is true only on c1. Track diagnosis accuracy, SLE false positives across c2 to c12, discriminator accuracy, and decoy accuracy separately. decoy should identify the one detail doing the misleading work; a list of every abnormality is not full credit.
Original forcing findings. c1 anti-Smith with anti-dsDNA and low complement; c2 acute parvovirus serology; c3 three positive Streptococcus gallolyticus cultures plus vegetation; c4 quotidian fever, evanescent rash, and ferritin 14,200; c5 ADAMTS13 below 5 percent with inhibitor; c6 the Lofgren triad.
Everyday-noise cases. c7 is an inferior STEMI after Thanksgiving dinner; the ECG and rising troponin outrank the food story. c8 is carbon monoxide poisoning; carboxyhemoglobin 28 percent, the furnace, and two sick cats outrank blood alcohol 0.06 percent and a normal pulse oximeter. c9 is a recurrent opioid toxidrome after four two-serving kratom/kava tonics; naloxone response outranks a negative routine opiate screen. c10 is overt autoimmune postpartum hypothyroidism. c11 is early disseminated Lyme disease with erythema migrans and facial palsy. c12 is dermatomyositis with objective proximal weakness, Gottron papules, CK 8,600, and anti-Mi-2.
nextStep distinguishes recognition from usable judgment: emergency reperfusion on c7, 100 percent oxygen on c8, ventilation plus repeat naloxone on c9, and urgent swallowing/respiratory assessment on c12. Drug-induced lupus remains excluded because reasonable clinicians can classify it differently, which would make a binary key indefensible.
Twelve patients have arrived with lupus somewhere in the story: in a referral, a portal search, an old lab result, or somebody's worried guess. Give the diagnosis. Some details are useful, some are merely true, and some happened on the same day by bad luck.
[1] id=c1 26-year-old woman. Four months of fatigue and symmetric pain and swelling in the small joints of both hands. Erythema across both cheeks and the bridge of the nose, sparing the nasolabial folds, worse after a weekend outdoors. Two painless ulcers on the hard palate. WBC 2.9, lymphocytes 0.7, platelets 118, hemoglobin 10.4. Creatinine 1.1. Urinalysis 2+ protein with dysmorphic red cells; urine protein:creatinine 1.4 g/g. ANA 1:640 speckled. Anti-dsDNA positive. Anti-Smith positive. C3 62 mg/dL, C4 8 mg/dL, both low. Direct antiglobulin test negative.
[2] id=c2 34-year-old woman. Nine days of abrupt symmetric pain and swelling in the MCPs, PIPs, wrists and knees. Morning stiffness two hours. Afebrile. No rash. Her six-year-old was sent home from school two weeks earlier with a bright red facial rash that faded into a lace pattern on his arms. WBC 6.1, platelets 244, hemoglobin 13.0. Creatinine 0.8. Urinalysis normal. ANA 1:80 speckled. Rheumatoid factor weakly positive. Anti-dsDNA negative. Anti-CCP negative. C3 and C4 normal. Parvovirus B19 IgM positive, IgG negative.
[3] id=c3 61-year-old man. Six weeks of low-grade fever, night sweats and 12 lb weight loss. New 2/6 systolic murmur at the apex. Splinter hemorrhages under two nails, tender nodules on the finger pads. Hemoglobin 9.8, ESR 88, CRP 96. Creatinine 1.6. Urinalysis with red cell casts. C3 low. ANA 1:160. Rheumatoid factor positive. Three of three blood culture sets grow Streptococcus gallolyticus. Transesophageal echo shows a 12 mm mitral valve vegetation.
[4] id=c4 29-year-old man. Five weeks of fever spiking to 39.6 C each evening and back to normal by morning. Sore throat at every spike, culture negative. A salmon-pink macular rash appears on the trunk with the fever and is gone by breakfast. Swollen wrists and knees. WBC 19,400 with 88 percent neutrophils. Hemoglobin 10.1, platelets 480. Ferritin 14,200 ng/mL. AST 78, ALT 92. ANA negative. Rheumatoid factor negative. Blood cultures negative x3. CT chest, abdomen and pelvis unremarkable.
[5] id=c5 41-year-old woman. Four days of confusion, bruising and fatigue. Temperature 38.1 C. Hemoglobin 7.6, platelets 11,000, reticulocytes elevated. LDH 1,180. Haptoglobin undetectable. Schistocytes on the smear. Creatinine 1.4. Direct antiglobulin test negative. PT and aPTT normal, fibrinogen normal. ANA negative. ADAMTS13 activity below 5 percent with an inhibitor detected.
[6] id=c6 33-year-old woman. Three weeks of fever, tender red nodules on both shins, and painful swollen ankles. WBC 8.2, hemoglobin 12.9, platelets 310. Calcium 10.9. Creatinine 0.9. Serum ACE elevated. ANA negative. Rheumatoid factor negative. Chest radiograph shows bilateral hilar lymphadenopathy with clear lung fields.
[7] id=c7 54-year-old woman. After Thanksgiving dinner — turkey, stuffing, two slices of pie, and enough antacid to make everyone comment — she develops burning pressure high in the abdomen. Her family calls it indigestion. Twenty minutes later she is pale, sweaty, and says the pressure is moving into her jaw. She has had months of tiredness and aching fingers, and an urgent-care ANA last year was 1:160 speckled. No joint swelling, oral ulcers, or photosensitive rash. ECG shows 2 mm ST elevation in leads II, III, and aVF with reciprocal ST depression in I and aVL. High-sensitivity troponin is above the 99th percentile and rising. Bedside ultrasound shows inferior-wall hypokinesis; gallbladder ultrasound is normal.
[8] id=c8 47-year-old woman who lives alone with two cats. A neighbor finds her confused on the sofa late on a January night, Netflix still asking whether she is watching. There is an empty wineglass beside her and her blood ethanol is 0.06 percent. Both cats are unusually limp. She had complained by text of a pounding headache and nausea after turning up an old gas furnace. Her pulse oximeter reads 99 percent. A prior workup for hand aches found ANA 1:80; anti-dsDNA was negative and complement normal. Venous carboxyhemoglobin is 28 percent. Lactate is 5.1 mmol/L. Head CT is normal.
[9] id=c9 38-year-old long-haul trucker. At a fuel stop he buys several tiny blue bottles of "feel free CLASSIC," shelved with energy shots. He says he thought each bottle was one serving; the label says two. During the night drive he drinks four bottles because the first "didn't do much." At the next stop he is difficult to wake, breathing 6 times a minute, with pinpoint pupils and oxygen saturation 82 percent. His dispatch paperwork mentions a positive ANA from a remote rash evaluation, and that result follows him into the emergency note. The bottles list kava and leaf kratom. Glucose is normal. He wakes and breathes 14 times a minute after naloxone, then becomes sleepy again 25 minutes later. Standard opiate immunoassay is negative; targeted liquid chromatography detects mitragynine and finds no fentanyl, methadone, or buprenorphine.
[10] id=c10 32-year-old woman, five months after delivery. She messages that she is exhausted, her hair is coming out in the shower, both hands ache in the morning, and searching those symptoms led her to lupus. She has gained 18 lb despite poor appetite and now needs a sweater in a warm room. No synovitis, rash, ulcers, chest pain, or urinary symptoms. ANA is 1:160 homogeneous; anti-dsDNA and anti-Smith are negative, and C3 and C4 are normal. TSH is 38 mIU/L, free T4 is low, and thyroid peroxidase antibody is strongly positive. Urinalysis and CBC are normal.
[11] id=c11 41-year-old youth soccer coach. After a week of camps in Connecticut, she notices an expanding red patch behind one knee but blames a new brand of shin guard. Two weeks later she has headache, migrating aches, and weakness on the left side of her face; she cannot fully close that eye. Her phone search says "malar rash plus joint pain equals lupus." ANA is 1:80 speckled, anti-dsDNA negative, complement normal. The patch is 14 cm across with central clearing and is still expanding. Lyme two-tier testing has a positive screening immunoassay and positive confirmatory IgM appropriate to symptom duration. ECG shows normal PR interval.
[12] id=c12 44-year-old woman. She starts a six-week strength challenge and assumes the soreness is the program working. Now she needs both arms to rise from a chair, cannot lift a hair dryer, and coughs when drinking water. A purple discoloration surrounds both eyes; scaly papules cross the knuckles, and a red shawl-like rash worsens in the sun. ANA is 1:320 and an online symptom checker says lupus. Creatine kinase is 8,600 U/L, aldolase is elevated, MRI shows symmetric proximal muscle edema, and anti-Mi-2 antibody is positive. Urinalysis has heme on dipstick with no red cells on microscopy.
diagnosis is one specific condition. Not a category, not a differential, not two conditions joined by "or".isSle is true only if the patient has systemic lupus erythematosus. Judge each case on its own.discriminator names the single finding that decides it against the nearest alternative. One phrase. Name the finding, not the reasoning.decoy names the detail most likely to pull a reader toward lupus or toward the wrong everyday explanation. One phrase. Do not call every abnormal result a decoy; identify the one that does the misleading work. Use "none" only if the case has no meaningful decoy.nextStep is the one thing you do next — the test, the drug, or the referral. If the patient is unstable, give the immediate action rather than the eventual workup.note is yours. Use it for the caveat, the alternative you could not fully exclude, or the point you would raise if a colleague pushed back. One or two sentences. Leave it as an empty string if you have nothing to add.Raw JSON, nothing else. No markdown fence, no preamble, no commentary after.
{
"rows": [
{ "id": "...", "diagnosis": "...", "isSle": false, "discriminator": "...", "decoy": "...", "nextStep": "...", "note": "..." }
]
}
Keys in that order. isSle is a boolean, not a string.