Coeliac disease — structured clinical encounter

Station brief (candidate)

You are the paediatric registrar in a general paediatric clinic. A fourteen-year-old is referred with tiredness and pallor. Her full blood count shows a microcytic anaemia with a haemoglobin of ninety-two grams per litre that has not corrected despite three months of oral iron. She has fallen from the fiftieth to the ninth centile for height, has intermittent abdominal bloating, and her maternal aunt has coeliac disease. She eats a normal gluten-containing diet. The team asks you to establish the differential and the workup, to explain a diagnostic rule, to state whether a biopsy can be avoided, and then to proceed to the management and family counselling. You have twelve minutes with the team and five minutes for examiner discussion. [2]

Information available on request

• Fourteen years old, previously well; tiredness and pallor for six months; no overt blood loss, normal periods. [2]
• Microcytic anaemia, haemoglobin ninety-two grams per litre, low ferritin, normal folate and vitamin B12, despite three months of oral iron. [3]
• Height fallen from the fiftieth to the ninth centile; weight stable; intermittent abdominal bloating; no diarrhoea. [5]
• Family history: maternal aunt with coeliac disease. Eats a normal gluten-containing diet. [1]
• Coeliac serology (on request): immunoglobulin A anti-tissue-transglutaminase at twelve times the upper limit of normal; endomysial antibody positive on a separate sample; total immunoglobulin A normal. [4]

Tasks

1. Give the differential and identify the features that put coeliac disease at the top. Grade the priority of your differential. [2]
2. Outline the serological workup and explain why a total immunoglobulin A must accompany the first test. [3]
3. A colleague suggests starting a gluten-free diet immediately and checking the antibodies in a month. Explain why this is wrong. [1]
4. State the diagnosis you can now make and how the ESPGHAN 2020 criteria apply to this girl. [1]
5. Outline the management and counsel the family on the outlook. [5]

Marking anchors

Must-hit

• Recognises that refractory iron-deficiency anaemia, the fall across the height centiles and the family history put coeliac disease at the top of the differential, and explains that iron is absorbed at the duodenal tip where the atrophy is worst, which is why the anaemia is refractory to oral iron. [2] [3]
• Explains that coeliac serology must be taken while the child is still eating gluten, because a gluten-free diet normalises the antibodies within weeks and the mucosa heals within months, making the diagnosis unconfirmable without a formal gluten challenge. [1]
• Applies the ESPGHAN 2020 no-biopsy pathway correctly: in this symptomatic girl with an anti-tissue-transglutaminase titre at or above ten times the upper limit of normal and a positive endomysial antibody on a separate sample, with a normal total immunoglobulin A, coeliac disease can be diagnosed without duodenal biopsy, the human leukocyte antigen requirement having been dropped in 2020. [1] [4]

Merit

• States that management is a strict lifelong gluten-free diet with a specialist dietitian, correction of the iron deficiency, and monitoring of symptom resolution, catch-up growth and a falling anti-tissue-transglutaminase titre that should normalise within six to twelve months, with annual review and screening of first-degree relatives, and counsels the family that the outlook on a strict diet is excellent. [5]

Fail

• Starts a gluten-free diet before the serology is taken, or accepts a negative serology taken after gluten withdrawal, thereby making the diagnosis unconfirmable. [1]
• Omitting the total immunoglobulin A and missing a coexisting selective immunoglobulin A deficiency that could have made the screen falsely negative, or attributing the anaemia and short stature to diet and menorrhagia alone without testing the gut. [3]