For learning clinical reasoning and educational purpose use only — not a diagnostic or clinical decision-support tool.
Vibe Rounds — Clinical Decision Science · Interactive Decision Lab
Case source ↗ avi33tbtt.github.io ↗
Clinical Decision Science · Interactive Decision Lab

Unfold the mystery: why is this 15-year-old running out of iron?

Every box below is a real fork the clinician faced. Click an option to test your reasoning against the expert rationale, the common pitfall, the evidence behind it, and — where it applies — how the patient's own voice and the realities of resource-limited care should shape the choice.

Age / Sex
15F, Std IX
Presenting complaint
Fatigue + giddiness, 5–6 mo
Exam
Pallor ++, Koilonychia +
Menstrual
Irregular cycles, 1 yr
Past history
Transfusion, age ~9
Final diagnosis
Iron deficiency anemia
Low-resource setting
Legend Clinical importance Time urgency Click any option to reveal rationale + pitfall. Use Solve for me for the expert path. Toggle Low-resource setting to see the pragmatic alternative when labs/imaging/blood bank aren't available.

Differential tracker

Updates live as you (or "Solve for me") make choices — this is the mystery unfolding across the whole case, not just one card.

Clinical Decision Science · Learner Map Set

The tired 9th-grader: mapping the decisions behind koilonychia and a falling Hb

A 15-year-old girl, 5–6 months of easy fatiguability and exertional giddiness, pallor and koilonychia on exam, irregular heavy-ish cycles for a year, and a transfusion six years ago. Each map below isolates one decision point a clinician (or clerking student) actually has to make, and rates it for teaching purposes.

Age / Sex
15F, Std IX
Core complaint
Fatigue + giddiness, 5–6 mo
Exam
Pallor ++, Koilonychia +
Vitals
BP 110/70, PR 84, RR 18
Menstrual
Irregular cycles, 1 yr
Final Dx
Iron deficiency anemia
How to read each map Clinical Importance (1–5) — how much this decision changes management or outcome Time Urgency (1–5) — how quickly the decision must be acted on Node colors: teal = action/data-gather, amber = decision branch, red = red-flag/critical check, green = endpoint
MAP 01

First 5 minutes — triaging "fatigue + giddiness" in an adolescent

Before chasing anemia, the student must decide whether this presentation could be something time-critical masquerading as simple tiredness.

Large map — initial triage logicIs this anemia, or something that looks like it?
Importance 4/5
Urgency 3/5
PATIENT ENTERS: fatigue + exertional giddiness x 5–6 mo
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Red-flag screenChest pain, syncope (not just giddiness), pedal edema, SOB at rest?Rule out cardiac/decompensation
Bleeding screenPR bleed, dark stools, hematemesis, menorrhagia (true, not just irregularity)?Rule out active hemorrhage
Infection/marrow screenFever pattern, bone pain, lymphadenopathy, bruising, recurrent infections?Rule out leukemia/aplasia
↓
This case: no SOB/edema (cardiac decompensation unlikely), no PR bleed/dark stools (no overt GI loss), fever was self-limiting 10 days prior (unlikely ongoing marrow suppression) → proceed down the anemia work-up track, but keep these on the differential until Hb/smear return.
↓
Decision: manage as outpatient anemia work-up (stable vitals, no red flags) rather than emergency referral
Teaching point: the urgency here is moderate, not low — a normal-looking BP/PR in a compensated anemic adolescent can mask significant Hb drop. The importance is high because misclassifying this as "just tiredness" delays a treatable diagnosis for months (as it already has, at 5–6 months).
MAP 02–03

Two history forks that decide the differential

Small, focused maps — each is a single fork a student must recognize while taking history.

Small map — menstrual historyIrregular cycles x 1 year: cause or coincidence?
Importance 5/5
Urgency 2/5
Menarche 12y, regular x 2y, then irregular x 1y, 5 days flow, no clots/menorrhagia by report
↓
Quantify pad count and days, not just "irregular" — patient self-report of "no menorrhagia" is often unreliable in teensAsk again, specifically
↓
Even "normal" volume + irregular timing, sustained a full year in a growing adolescent, is enough cumulative loss to explain/worsen IDATreat as contributing cause
↓
Decision: menstrual blood loss = leading driver to correct alongside iron repletion; consider gynae referral if it doesn't regularize after Hb correction
Why it matters most: in a 15-year-old, ongoing menstrual loss is the single most common reason iron therapy fails to hold — miss this fork and the anemia relapses after treatment stops.
Small map — dietary history"Good appetite, mixed diet" — does that rule out nutritional cause?
Importance 3/5
Urgency 1/5
Mixed diet, 3 meals/day, fruits regularly, no pica reported
↓
"Mixed diet" does not equal adequate heme-iron intake — ask what fraction is actually flesh foods vs. cereal/vegetable-based (phytate-rich)Probe composition, not just variety
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Typical regional diet + ~5% non-heme iron bioavailability + adolescent growth demand = plausible dietary insufficiency even without pica or poor appetite
↓
Decision: counsel on heme-iron/vitamin-C pairing; diet is a contributing, correctable factor — not the sole explanation given menstrual loss also present
Teaching point: a "good" diet history should never fully close the nutritional differential in a menstruating teenager — treat it as low urgency but still worth correcting.
MAP 04

From exam findings to confirmed microcytic hypochromic anemia

The core diagnostic decision map — what to order, in what order, and how to interpret it.

Large map — investigation pathwayPallor + koilonychia → confirming iron deficiency anemia
Importance 5/5
Urgency 3/5
EXAM: pallor ++, koilonychia +, no organomegaly, CVS/CNS normal
↓
First-lineCBC with red cell indices (Hb, MCV, MCH, MCHC) + peripheral smearOrder first
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MCV/MCH low (microcytic, hypochromic)?
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YES — microcytic hypochromic patternConsistent with this patient
↓
Differentiate IDA vs. thalassemia trait vs. anemia of chronic disease
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Correlate with smear morphology (anisopoikilocytosis, pencil cells favor IDA) ± serum ferritin/iron studies if availableConfirms IDA
↓
DIAGNOSIS: Iron deficiency anemia
NO — normocytic/macrocytic insteadBranch not taken here
↓
Reconsider: hemolysis, marrow suppression, B12/folate deficiency, chronic disease
↓
Would change management entirely — do not force-fit into IDAEscalate work-up
↓
Alternate pathway (not this patient)
Teaching point: the decision that carries the most weight in the whole case is confirming the anemia is truly microcytic-hypochromic before anchoring on "iron deficiency" — this is rated 5/5 importance because every downstream decision (treatment, need for further GI/gynae work-up) depends on it.
MAP 05–06

Context that changes the plan

A past transfusion and the treatment choice itself are each small but consequential decisions.

Small map — past historyBlood transfusion 6 years ago "due to low Hb" — how far back to dig?
Importance 4/5
Urgency 2/5
H/o blood transfusion at age ~9 for "low Hb," cause not detailed
↓
Was that episode ever explained, or just treated? A second severe anemia episode years later raises the question of a recurring/chronic driverDon't accept "low Hb" as a diagnosis
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Ask specifically about prior records, any thalassemia/hemoglobinopathy screening, family history of anemia or transfusions
↓
Decision: treat as first-episode-per-history, but flag for hemoglobinopathy screening if response to iron is poor or MCV is disproportionately low for the Hb
Why this is easy to miss: students often log the transfusion as a throwaway past-history line rather than a clue that this may not be a purely nutritional, one-off problem.
Small map — treatment & follow-upStarting oral iron: what decision comes next?
Importance 4/5
Urgency 2/5
Start Tab Orofer-XT (oral iron) BD
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Counsel on adherence (GI upset, stool color) — decide follow-up interval for Hb recheck (~2–4 weeks for reticulocyte/Hb response)Plan the recheck now
↓
At recheck: adequate Hb rise?
YESContinue 3 months to replete stores
NO / poor responseReassess: adherence, ongoing loss (menstrual), malabsorption, wrong diagnosis
↓
Decision: don't treat "start iron" as the end of the case — the follow-up check is where under-dosing or a missed diagnosis gets caught
MAP 07

The whole case as one decision spine

A single large map stringing the prior decisions together in sequence, for revision.

Large map — full case spinePresentation to management, in one line of decisions
Importance 5/5
Urgency 3/5
1. Triage for red flags
2. Targeted history (menstrual + diet + past)
3. Exam (pallor, koilonychia)
4. CBC + smear
5. Confirm microcytic hypochromic pattern
↓
6. Diagnose IDA → 7. Start oral iron → 8. Counsel on menstrual/dietary contributors → 9. Plan Hb recheck → 10. Escalate work-up only if response fails
How to use this map: each numbered step corresponds to one of Maps 01–06 above. A student who can independently rate why step 5 (confirming the anemia pattern) is more important than step 2 in isolation, but why step 2 is what determines whether treatment actually holds long-term, has understood the case.