Bleeding child: diagnostic approach: Viva

Opening question

What is your diagnostic approach to this girl, and what is the single most important thing you would do before ordering any laboratory tests? [5]

This girl has abnormal bleeding: heavy menstrual bleeding from menarche with flooding, clots, and iron deficiency, plus a lifelong history of epistaxis and easy bruising. This is a primary-hemostasis (platelet-type) pattern, immediate and mucocutaneous, with a normal platelet count. Before any laboratory test, the single most important step is to quantify the bleeding history with a validated bleeding assessment tool, because it confirms the bleeding is abnormal and distinguishes a bleeding disorder from normal childhood bruising far better than impression. I would also take a careful family history, because heavy menstrual bleeding is the commonest presentation of Von Willebrand disease and the inherited platelet function disorders in females. [5]

Branch 1: The first-line screen

What first-line tests would you send, and how would you interpret a normal prothrombin time and a borderline activated partial thromboplastin time? [1]

I would send a full blood count and blood film, a prothrombin time, an activated partial thromboplastin time, a fibrinogen, and a blood group, at the first venepuncture and before any transfusion. The film quantifies the platelet count and excludes leukaemia or fragmented cells. A normal prothrombin time and a borderline activated partial thromboplastin time are entirely consistent with Von Willebrand disease, because Von Willebrand factor carries and stabilises factor VIII, so a low level can lower factor VIII and mildly prolong the activated partial thromboplastin time, but a normal screen never excludes the diagnosis. [1]

Branch 2: The Von Willebrand disease workup

The bleeding assessment tool confirms abnormal bleeding. What is the next step, and how do you avoid the common diagnostic pitfall? [5]

The next step is specific Von Willebrand disease testing: Von Willebrand factor antigen, a functional assay such as ristocetin cofactor activity or a glycoprotein Ib-binding assay, factor VIII, and multimer analysis to subtype. The common pitfall is diagnosing or excluding Von Willebrand disease on a single value, because Von Willebrand factor is an acute-phase reactant that rises with stress, illness, and venepuncture, and the level is strongly influenced by blood group, with group O giving lower levels. The 2021 international guidelines stress that a borderline low value should be repeated before a diagnosis is made or excluded. [5]

Branch 3: The normal-screen pitfall

Suppose the Von Willebrand factor assays return normal. Does that exclude a bleeding disorder, and what would you do next? [1]

No, a normal result does not exclude a bleeding disorder, because the bleeding history is convincing. A single normal Von Willebrand factor level can mask the diagnosis for the reasons above, so I would repeat the assays. If they remain normal, I would proceed to platelet function testing with light transmission aggregometry or a flow-cytometric platelet screen, because inherited platelet function disorders such as Glanzmann thrombasthenia produce a similar mucocutaneous pattern with a normal screen. I would not reassure the family on the basis of a single normal panel. [1]

Branch 4: Immediate management

How would you manage her menorrhagia while the workup proceeds? [1]

I would manage the menorrhagia alongside the workup rather than waiting for the diagnosis. A combined hormonal contraceptive pill or a levonorgestrel intrauterine system controls the menstrual bleeding, and tranexamic acid is a useful antifibrinolytic adjunct for mucosal bleeding. I would also treat her iron deficiency anaemia with oral iron. Once the diagnosis is confirmed, Von Willebrand disease type 1 may be treated with desmopressin, which releases stored Von Willebrand factor and factor VIII from endothelium, while type 3 or major bleeding needs Von Willebrand factor-containing concentrates. [1]

Closing question

Summarise the platelet-versus-coagulation distinction in a way you could teach a junior colleague. [2]

The pattern of bleeding tells you which phase of hemostasis has failed before any test is sent. Platelet-type bleeding is immediate, mucocutaneous, and petechial, because the platelet plug that should form in seconds is missing or faulty, and the causes are thrombocytopenia and platelet dysfunction including Von Willebrand disease. Coagulation-type bleeding is delayed by hours and deep, into joints and muscles, because the fibrin reinforcement of the plug never forms, and the causes are the factor deficiencies led by haemophilia A and B. Reading the pattern first, then sending the screen, turns a scattergun workup into a focused one. [2]

Examiner notes

This viva assesses the candidate's ability to quantify the bleeding history with a bleeding assessment tool, recognise the primary-hemostasis pattern of mucocutaneous bleeding with a normal count, and pursue the Von Willebrand disease workup without being falsely reassured by a normal or borderline screen. Key teaching points are the obsolescence of the bleeding time, the stress-responsiveness and blood-group dependence of Von Willebrand factor, the need to repeat borderline levels, and the move to platelet function testing when Von Willebrand factor assays are normal. Strong candidates name the specific Von Willebrand factor assays, the role of desmopressin in type 1, and the management of menorrhagia in parallel with the workup. [5]