Family Medicine Board Review · Case-Based · Difficult Level

Bleeding & Bruises / VWD — Clinical Vignette MCQs

Board-style cases built from the bleeding/bruising and VWD summary — screening thresholds, platelet vs. coagulation bleeding patterns, drug/disease lab profiles, PT/aPTT pathway logic, and the full VWD diagnostic and treatment workup. Tap "Reveal Answer" on each, then read the pearl.

15 Questions ●●●● Difficult Single Best Answer

Q1ISTH-BAT Thresholds●●●●● Extreme

Three patients undergo bleeding assessment using the ISTH-BAT: a 35-year-old man scores 4, an 8-year-old girl scores 3, and a 40-year-old woman scores 4. Which patient(s) have an abnormal score requiring further evaluation?

A. Only the man
B. The man (score 4 >3) and the girl (score 3 >2) both have abnormal scores; the woman's score of 4 is NOT abnormal (threshold >5)
C. Only the woman
D. All three patients have normal scores
E. All three patients have abnormal scores using an identical universal threshold

Reveal Answer

Correct answer: B

ISTH-BAT abnormal thresholds are age/sex-specific: >3 in adult males (his score of 4 exceeds this), >5 in adult females (her score of 4 does NOT exceed this), and >2 in children (her score of 3 exceeds this). So the man and the girl both screen abnormal; the woman does not.

Why the others are wrong A — the girl also has an abnormal score given the lower pediatric threshold. C — the woman's score of 4 is actually below (not above) her threshold of 5. D — both the man and girl have abnormal scores. E — there is no single universal threshold; it varies by age/sex group.

Exam Pearl ISTH-BAT thresholds: >3 (adult males), >5 (adult females), >2 (children). The same raw score can be normal or abnormal purely depending on which group the patient falls into.

Q2Platelet vs. Coagulation Pattern●●●● Very Hard

A 22-year-old man presents with recurrent spontaneous knee hemarthroses and a deep thigh muscle hematoma after minimal activity. A different 25-year-old woman presents with recurrent epistaxis, gum bleeding, and heavy menstrual periods. Which type of bleeding disorder is most likely in each?

A. Both patients most likely have platelet disorders
B. The man's pattern (hemarthroses, muscle hematoma) suggests a coagulation disorder (e.g., hemophilia); the woman's pattern (mucocutaneous bleeding) suggests a platelet disorder (e.g., VWD)
C. The man's pattern suggests a platelet disorder, and the woman's suggests a coagulation disorder
D. Both patients most likely have coagulation disorders
E. Bleeding pattern location has no diagnostic value in distinguishing these categories

Reveal Answer

Correct answer: B

Coagulation disorders (e.g., hemophilia) should be suspected with spontaneous hemarthroses and muscle hematomas — matching the man's presentation. Platelet disorders (e.g., VWD, ITP) should be suspected with mucocutaneous bleeding (epistaxis, gum bleeding, menorrhagia) — matching the woman's presentation.

Why the others are wrong A/D — the two patients have distinctly different bleeding patterns pointing to different disorder categories, not the same category for both. C — this reverses the correct pairing. E — bleeding pattern/location is specifically diagnostically useful and is the primary initial triage tool in this framework.

Exam Pearl Mucocutaneous bleeding → platelet disorder. Hemarthrosis/muscle hematoma → coagulation factor disorder. This is the single most efficient triage question when evaluating a new bleeding complaint.

Q3Medication-Induced — 10-Day Rule●●●●● Extreme

A 55-year-old man developed thrombocytopenia while on a new antibiotic. The antibiotic was discontinued 12 days ago, and his platelet count remains low with ongoing bruising. What is the most appropriate next step?

A. Continue to observe without further workup, since drug-induced thrombocytopenia always eventually resolves regardless of timeframe
B. Initiate further evaluation for an underlying bleeding disorder, since his symptoms/low platelet count have persisted beyond 10 days after discontinuation
C. Restart the antibiotic to confirm the diagnosis
D. No further action is needed since the medication has already been stopped
E. Diagnose VWD without any additional testing

Reveal Answer

Correct answer: B

If bleeding symptoms or a low platelet count persist 10 days after discontinuation of the suspected offending medication, further evaluation for a bleeding disorder should be initiated. His 12-day persistence exceeds this window, warranting expanded workup rather than continued simple observation.

Why the others are wrong A — the specific 10-day rule exists precisely because persistence beyond that point should NOT simply be observed further; it should trigger additional workup. C — rechallenging with the suspected offending drug is inappropriate and could worsen the thrombocytopenia. D — stopping the medication alone is not sufficient once the 10-day persistence threshold has been crossed; further evaluation is specifically indicated. E — VWD (or any specific diagnosis) shouldn't be assumed without appropriate confirmatory testing.

Exam Pearl Bleeding/thrombocytopenia persisting >10 days after stopping the suspected drug → evaluate for an underlying bleeding disorder. A specific, memorizable numeric cutoff.

Q4Physical Exam Threshold●●●○ Hard

A 10-year-old boy is brought in for evaluation of easy bruising. Exam reveals 7 bruises ranging from 1.5–3 cm on his trunk and extremities, without a clear history of trauma for most of them, plus several atraumatic petechiae. What is the significance of these findings?

A. These findings are within normal limits for an active child and require no further concern
B. These findings (≥5 bruises >1 cm, truncal location, atraumatic petechiae) suggest an underlying bleeding disorder and warrant further evaluation
C. Only the petechiae are significant; the bruising is entirely normal regardless of number or location
D. These findings are diagnostic of hemophilia specifically, with no other possible etiology
E. Bruise size and number are irrelevant to bleeding disorder evaluation

Reveal Answer

Correct answer: B

Findings suggestive of a bleeding disorder on exam include truncal bruising, 5 or more bruises greater than 1 cm in diameter, and atraumatic petechiae or hematomas — this child meets multiple of these criteria (7 bruises >1cm including truncal location, plus atraumatic petechiae), warranting further evaluation.

Why the others are wrong A — this specific combination of findings (number, size, location, atraumatic petechiae) exceeds what's considered normal childhood bruising and should prompt evaluation. C — the bruising pattern itself (number, size, truncal location) is independently significant, not just the petechiae. D — these findings suggest a bleeding disorder broadly (platelet or coagulation factor-related) but aren't specifically diagnostic of hemophilia alone; further workup (including distinguishing platelet vs. coagulation patterns) is needed. E — bruise size, number, and location are specifically part of the defined exam criteria for concern.

Exam Pearl Concerning exam findings: truncal bruising, ≥5 bruises >1 cm, and atraumatic petechiae/hematomas. These are concrete, memorizable red flags distinguishing pathologic from typical childhood bruising.

Q5Prolonged PTT — No Bleeding●●●●● Extreme

A 30-year-old asymptomatic man is found to have an isolated prolonged PTT on preoperative labs, with no personal or family history of bleeding and no abnormal bleeding during a prior dental extraction. What is the most likely explanation, and what is the most appropriate next step?

A. This is diagnostic of hemophilia A and he should be started on factor VIII replacement before any procedure
B. This may represent a benign cause such as an early contact factor deficiency (Factor XII, HMWK, PK), lupus anticoagulant, or a laboratory artifact — these do not typically cause clinical bleeding
C. He should be immediately started on DDAVP
D. This finding always indicates DIC and requires urgent hematology admission
E. No further consideration of the differential is needed; the test should simply be ignored

Reveal Answer

Correct answer: B

An isolated prolonged PTT in a patient without bleeding history (including no bleeding with a prior invasive procedure like dental extraction) is often explained by benign causes: early contact factor deficiency (Factor XII, HMWK, PK), lupus anticoagulant, inappropriate blood draw, heparin contamination, or erythrocytosis (lab artifact) — none of which typically cause clinical bleeding.

Why the others are wrong A — hemophilia A is a bleeding-associated coagulation disorder; his lack of bleeding history (including a prior uneventful dental extraction) argues against this and favors a benign cause instead. C — DDAVP is a VWD treatment, not indicated based on an isolated asymptomatic PTT prolongation. D — DIC is an ill, actively bleeding/clotting clinical picture, not an incidental asymptomatic lab finding. E — while the finding is likely benign, it still merits consideration of this specific differential rather than blanket dismissal.

Exam Pearl Prolonged PTT + no bleeding history/no bleeding with prior procedures = likely benign (contact factor deficiency, lupus anticoagulant, artifact). This pattern should reassure rather than trigger aggressive factor replacement.

Q6Warfarin Lab Pattern●●●○ Hard

A 70-year-old woman on warfarin for atrial fibrillation has coagulation studies drawn. Which pattern is expected?

A. Prolonged PT, normal aPTT, normal bleeding time, normal platelet count
B. Normal PT, prolonged aPTT, normal bleeding time, normal platelet count
C. Prolonged PT, prolonged aPTT, prolonged bleeding time, low platelet count
D. Normal PT, normal aPTT, prolonged bleeding time, normal platelet count
E. Prolonged PT, prolonged aPTT, normal bleeding time, low platelet count

Reveal Answer

Correct answer: A

Warfarin produces a classic pattern: prolonged PT, normal aPTT, normal bleeding time, and normal platelet count — warfarin primarily affects vitamin K-dependent factors (II, VII, IX, X), with factor VII (extrinsic pathway, reflected by PT) being particularly sensitive given its short half-life.

Why the others are wrong B — this describes the heparin pattern (prolonged aPTT with typically normal/occasionally prolonged PT), not warfarin. C — this describes the DIC pattern (all parameters deranged, low platelets), not isolated warfarin effect. D — this describes the aspirin pattern (isolated prolonged bleeding time from platelet dysfunction), not warfarin. E — this combination doesn't match any of the four classic patterns presented; warfarin specifically spares aPTT, bleeding time, and platelet count.

Exam Pearl Warfarin: PT up, everything else normal. Contrast directly with heparin (aPTT up), aspirin (bleeding time up only), and DIC (everything deranged plus low platelets).

Q7Aspirin Lab Pattern●●●● Very Hard

A 60-year-old man on daily aspirin for cardiovascular prophylaxis has easy bruising. Coagulation studies show normal PT, normal aPTT, prolonged bleeding time, and a normal platelet count. What does this pattern indicate?

A. This pattern is consistent with warfarin effect
B. This pattern is consistent with aspirin's known effect on platelet function, without affecting platelet count or the coagulation cascade itself
C. This pattern indicates DIC
D. This pattern is inconsistent with any known drug effect and should prompt an unrelated extensive workup
E. This pattern indicates heparin effect

Reveal Answer

Correct answer: B

Aspirin produces normal PT, normal aPTT, prolonged bleeding time, and normal platelet count — reflecting its mechanism of impairing platelet function (via irreversible COX inhibition) without affecting platelet number or the coagulation cascade (PT/aPTT) itself.

Why the others are wrong A — warfarin prolongs PT specifically, which is normal here; this pattern doesn't match warfarin. C — DIC deranges all four parameters including a low platelet count; this patient's platelet count and PT/aPTT are all normal. D — this is precisely the classic, expected aspirin pattern, not an inconsistent or unexplained finding. E — heparin prolongs aPTT, which is normal here; this pattern doesn't match heparin.

Exam Pearl Aspirin: bleeding time up, everything else (PT, aPTT, platelet count) normal. This isolated bleeding-time prolongation with an otherwise normal panel is the aspirin signature.

Q8DIC — The Platelet Differentiator●●●●● Extreme

A critically ill 45-year-old woman with septic shock has coagulation studies showing prolonged PT, prolonged aPTT, prolonged bleeding time, and a platelet count of 45 × 10⁹/L. Which of the four conditions (warfarin, aspirin, heparin, DIC) is most consistent with this complete pattern?

A. Warfarin effect
B. Aspirin effect
C. Heparin effect
D. DIC — the only one of these four conditions that characteristically causes a LOW platelet count alongside prolongation of PT, aPTT, and bleeding time
E. None of these conditions can explain a low platelet count

Reveal Answer

Correct answer: D

Among warfarin, aspirin, heparin, and DIC, only DIC characteristically produces a low platelet count alongside prolonged PT, aPTT, and bleeding time — reflecting the global consumptive coagulopathy (widespread clot formation consuming platelets and clotting factors) that defines DIC.

Why the others are wrong A — warfarin causes isolated PT prolongation with normal platelet count, aPTT, and bleeding time — not this global derangement. B — aspirin causes isolated bleeding time prolongation with normal platelet count, PT, and aPTT. C — heparin causes isolated aPTT prolongation with normal platelet count, PT, and bleeding time. E — this is factually incorrect; DIC specifically explains this full pattern including the low platelet count.

Exam Pearl Of the four classic lab patterns, DIC is the one and only condition with a LOW platelet count — a single differentiating lab value that immediately narrows the differential to DIC when everything (PT, aPTT, bleeding time, platelets) is abnormal together.

Q9PT/aPTT Pathway Logic●●●●● Extreme

A 28-year-old man has coagulation studies showing a normal PT and a markedly prolonged aPTT. He has a history of recurrent joint bleeds. What is the most appropriate interpretation of this pattern?

A. This indicates a disorder of the extrinsic coagulation pathway
B. This indicates a disorder of the intrinsic coagulation pathway (e.g., hemophilia A or B, factor VIII/IX deficiency)
C. This pattern is inconsistent with any coagulation factor disorder
D. This pattern specifically indicates a platelet disorder rather than a coagulation factor problem
E. PT and aPTT results have no relationship to specific coagulation pathways

Reveal Answer

Correct answer: B

A normal PT with a prolonged aPTT indicates a disorder of the intrinsic coagulation pathway — this pattern, combined with his history of recurrent hemarthroses (a coagulation-disorder bleeding pattern), is classic for hemophilia A or B (factor VIII or IX deficiency, both intrinsic pathway factors).

Why the others are wrong A — a prolonged PT with normal aPTT would indicate the extrinsic pathway; this patient has the opposite pattern (normal PT, prolonged aPTT). C — this pattern is specifically consistent with intrinsic pathway coagulation factor disorders, not inconsistent with any. D — his hemarthrosis-predominant bleeding pattern specifically suggests a coagulation factor disorder, not a platelet disorder (which would show mucocutaneous bleeding instead), and normal PT/aPTT (not prolonged) is typically seen in isolated platelet disorders. E — PT and aPTT do specifically map to the extrinsic and intrinsic pathways, respectively.

Exam Pearl "PTT = intrinsic, PT = extrinsic." Normal PT + prolonged aPTT + hemarthrosis history = classic hemophilia A/B presentation (intrinsic pathway factor VIII/IX deficiency).

Q10Confirming Low Platelet Count●●●○ Hard

A 33-year-old asymptomatic woman has a platelet count of 55 × 10⁹/L on routine labs drawn in a standard tube, with no bleeding symptoms and a normal exam. What is the most appropriate next step before proceeding with further bleeding disorder workup?

A. Proceed directly to bone marrow biopsy
B. Recollect the blood in a citrated or heparinized tube to confirm the low platelet count before further workup
C. Start empirical treatment for ITP immediately
D. No confirmation is needed; proceed directly with the count as reported
E. Order a coagulation panel as the only next step, bypassing platelet count confirmation

Reveal Answer

Correct answer: B

A low platelet count should be confirmed by recollecting the blood in a citrated or heparinized tube — this rules out pseudo-thrombocytopenia from platelet clumping in the standard EDTA collection tube before pursuing further bleeding disorder evaluation.

Why the others are wrong A — bone marrow biopsy is invasive and premature before simply confirming the count is accurate. C — treating for a specific diagnosis (ITP) before even confirming the platelet count is a true, reproducible finding is inappropriate. D — proceeding without confirmation risks basing further workup on a spurious, artifactually low result. E — platelet count confirmation should occur before or alongside other testing, not be bypassed.

Exam Pearl Any unexpected low platelet count should first be confirmed via a citrated or heparinized tube recollection — this simple step prevents unnecessary downstream workup based on a lab artifact.

Q11VWD Types●●●● Very Hard

A 24-year-old woman is diagnosed with von Willebrand disease showing a reduced (but present) quantity of structurally normal von Willebrand factor. Which type of VWD does this describe, and how common is it relative to the other types?

A. Type 3 — the most common type
B. Type 1 — reduced (quantitatively low but structurally normal) VWF; the most common type overall
C. Type 2 — dysfunctional VWF; the most common type overall
D. Type 3 — rare, with absent/undetectable VWF
E. This description does not correspond to any recognized VWD type

Reveal Answer

Correct answer: B

Type 1 VWD is characterized by reduced (quantitatively low, but structurally/functionally normal) VWF, and is the most common type of VWD overall.

Why the others are wrong A/D — Type 3 describes absent/undetectable VWF (the rare, most severe form), not reduced-but-normal VWF, and it is specifically the rarest type, not the most common. C — Type 2 describes dysfunctional (qualitatively abnormal) VWF with four subtypes, not simply reduced quantity, and while it's the second most common, Type 1 remains most common overall. E — this description precisely matches Type 1 VWD.

Exam Pearl VWD types: Type 1 = reduced VWF (most common); Type 2 = dysfunctional VWF, 4 subtypes; Type 3 = absent/undetectable VWF (rare, most severe).

Q12VWD — Joint Bleeding Exception●●●●● Extreme

A 19-year-old man with severe (Type 3) von Willebrand disease presents with recurrent knee hemarthroses, in addition to his baseline mucocutaneous bleeding. A colleague states this is unusual for VWD and should prompt reconsideration of the diagnosis. Is this correct?

A. Yes, joint bleeding never occurs in any form of VWD, and this should prompt an alternative diagnosis
B. No — while joint and muscle bleeding are not typical of VWD overall, they CAN be seen specifically with types 2N and 3, which this patient has
C. Yes, because VWD is exclusively a platelet-count disorder incapable of causing any coagulation-type bleeding
D. No, because joint bleeding is equally common across all three VWD types
E. Yes, and this finding specifically confirms Type 1 VWD

Reveal Answer

Correct answer: B

While joint and muscle bleeding are not typical of VWD in general, they specifically can be seen with types 2N and 3 — his Type 3 diagnosis explains this atypical hemarthrosis pattern. This occurs because severe VWF deficiency/dysfunction secondarily impairs factor VIII stabilization, producing hemophilia-like joint bleeding.

Why the others are wrong A — this is specifically the recognized exception for types 2N and 3; it should not automatically prompt reconsideration of the diagnosis in this patient. C — VWD is not a platelet-count disorder per se — it's a VWF quantity/function disorder that secondarily affects platelet adhesion and, in severe subtypes, factor VIII levels. D — joint bleeding is NOT equally common across all types; it is specifically an exception seen in types 2N and 3, uncommon in type 1 (and most of type 2). E — this pattern is specifically associated with type 3 (or 2N), not type 1.

Exam Pearl VWD is a mucocutaneous bleeding disorder overall — but types 2N and 3 are the exceptions that can produce hemarthrosis/muscle hematoma, mimicking hemophilia due to secondary factor VIII deficiency.

Q13VWF:Ag Cutoffs — Integrative●●●●● Extreme

Three patients undergo VWF antigen testing as part of a bleeding disorder workup: Patient A has a level of 22%, Patient B has a level of 40%, and Patient C has a level of 65%. What is the most appropriate interpretation and next step for each?

A. All three levels confirm VWD and require no further testing
B. Patient A (22%, <30%) — VWD confirmed; Patient B (40%, 30–50%) — retest; Patient C (65%, >50%) — normal level
C. All three levels are normal and exclude VWD
D. Patient A requires retesting, while Patients B and C are both diagnostic of VWD
E. VWF:Ag level has no established interpretive cutoffs

Reveal Answer

Correct answer: B

The VWF:Ag interpretation cutoffs are: <30% confirms VWD (Patient A's 22% falls here), 30–50% should be retested (Patient B's 40% falls here), and >50% is a normal level (Patient C's 65% falls here).

Why the others are wrong A — only Patient A's level actually confirms VWD by these criteria; Patient C's level is normal, and Patient B's requires retesting rather than an immediate diagnosis. C — Patient A's level of 22% specifically confirms, not excludes, VWD. D — this reverses/misapplies the correct interpretation for all three patients. E — specific, defined cutoffs (<30%, 30–50%, >50%) do exist and guide interpretation.

Exam Pearl VWF:Ag interpretation: <30% = confirms VWD; 30–50% = retest (gray zone); >50% = normal. Practice applying these three tiers to specific numeric values, as boards often test this as a direct calculation/categorization exercise.

Q14When to Consider VWD●●●● Very Hard

A 16-year-old boy is being worked up for suspected hemophilia A given a low factor VIII level and prolonged aPTT, but his bleeding pattern is primarily mucocutaneous (frequent nosebleeds, gum bleeding) rather than joint bleeding, and he has a family history of similar mild bleeding symptoms in his mother. What diagnosis should specifically be reconsidered?

A. This presentation is classic, uncomplicated hemophilia A with no other diagnosis to consider
B. Von Willebrand disease should specifically be considered, given "apparent hemophilia A," mucocutaneous bleeding pattern, and positive family history
C. Acute leukemia should be the leading alternative diagnosis
D. No further consideration is needed since factor VIII is already confirmed low
E. Iron deficiency anemia should replace hemophilia A as the primary differential

Reveal Answer

Correct answer: B

VWD should specifically be considered in patients with bleeding (especially mucocutaneous), positive family history, mild thrombocytopenia, unexplained prolonged aPTT, or apparent hemophilia A — this patient hits several of these specific triggers (low factor VIII/"apparent hemophilia A," mucocutaneous bleeding pattern, positive family history), since VWD can secondarily lower factor VIII (VWF normally stabilizes/protects factor VIII in circulation).

Why the others are wrong A — his mucocutaneous bleeding pattern (rather than the joint bleeding classic for hemophilia) and family history specifically argue for reconsidering VWD rather than accepting straightforward hemophilia A. C — nothing in this presentation suggests leukemia; the pattern specifically fits the VWD "when to consider" criteria. D — a low factor VIII specifically doesn't exclude VWD; it can be explained by VWD's effect on factor VIII stability, and this is exactly the scenario prompting reconsideration rather than closing the workup. E — iron deficiency anemia isn't relevant to this specific bleeding/coagulation pattern.

Exam Pearl "Apparent hemophilia A" is specifically listed as a trigger to consider VWD — because VWF stabilizes factor VIII, VWD can present with a secondarily low factor VIII and prolonged aPTT that mimics hemophilia A, especially when the bleeding pattern is mucocutaneous and family history is positive.

Q15Acquired vs. Inherited VWD●●●●● Extreme

A 66-year-old man with a newly implanted left ventricular assist device (LVAD) develops new-onset gastrointestinal bleeding 6 weeks after implantation. He has no personal or family history of bleeding problems prior to this. What is the most likely underlying diagnosis, and what distinguishes it from inherited VWD?

A. Inherited Type 1 VWD, which commonly first presents in the 60s
B. Acquired von Willebrand syndrome (AVWS) — distinguished by the new onset, association with a recognized underlying condition (LVAD), and absence of personal/family bleeding history
C. Inherited Type 3 VWD, given the severity of bleeding
D. This presentation is unrelated to any VWF-related process
E. Hemophilia A acquired from the LVAD device itself

Reveal Answer

Correct answer: B

Acquired von Willebrand syndrome (AVWS) is specifically associated with conditions like LVAD, and should be suspected in a patient with a recognized associated underlying condition and/or new-onset unexplained bleeding with no personal or family history of bleeding — exactly matching this patient's presentation (new LVAD, new bleeding, no prior bleeding history).

Why the others are wrong A/C — inherited VWD (any type) would be expected to have a lifelong history (or at least earlier-life symptoms/family history), not a sudden new onset tightly linked temporally to a new LVAD; his lack of prior personal/family history argues against an inherited form. D — LVAD-associated AVWS via high shear stress-induced VWF dysfunction is a well-recognized, specifically named association. E — this describes AVWS (a VWF-related process), not hemophilia A, and it isn't accurately described as "acquired hemophilia A" in this framework.

Exam Pearl AVWS: new-onset bleeding + no personal/family bleeding history + a recognized associated condition (LVAD, myeloproliferative/lymphoproliferative disease, autoimmune disease, high-flow cardiovascular states, hypothyroidism). This is the key pattern distinguishing it from lifelong inherited VWD.