Iron Deficiency — DCE Clinical Case

The instruction decoded

"Examine for signs of iron deficiency anaemia" is a three-part task: demonstrate the signs of anaemia, the specific signs of iron deficiency, and then — the mark of a physician — examine for the cause and the consequences [1] [3].

Systematic examination routine

Hands. Koilonychia — spoon-shaped, concave nails, the pathognomonic sign; brittle, ridged nails; palmar crease pallor for anaemia. Note also the resting pulse rate and any tachycardia [1] [2].

Eyes. Conjunctival pallor — the standard anaemia sign; no jaundice (its absence argued against haemolysis) [1].

Mouth. Angular cheilitis — fissuring at the lip corners; glossitis — a smooth, depapillated, sometimes sore red tongue; then ask about and assess for dysphagia, because long-standing iron deficiency with a post-cricoid web (Plummer-Vinson syndrome) carries a risk of post-cricoid squamous carcinoma [1] [2].

Face and neck. General pallor; no lymphadenopathy — then deliberately look for the haematological mimics: no splenomegaly yet [1].

Cardiovascular consequences. Tachycardia, a hyperdynamic apex, and a soft ejection-systolic flow murmur of severe anaemia; check for signs of heart failure that would change the tempo and the route of treatment [1].

The cause hunt — abdomen. Scars (previous gastric or bariatric surgery — malabsorption), masses (a caecal cancer is famously silent until the iron runs out), hepatomegaly, splenomegaly; offer a PR examination for melaena and masses, and a urinalysis where haemoglobinuria is plausible [3].

Clues to the non-GI causes. A dialysis fistula or transplant scar (CKD and functional iron deficiency); dermatitis herpetiformis on elbows and knees (coeliac); signs of rheumatoid disease or other chronic inflammation that would make the ferritin lie; in younger patients, a menstrual history is examination-adjacent and must be verbalised [3] [2].

Presentation template (deliver this to the examiner)

"Mrs Cole is comfortable at rest with no respiratory distress. She has conjunctival and palmar pallor consistent with anaemia. There are specific signs of iron deficiency: early koilonychia of the fingernails and a smooth, depapillated tongue with angular cheilitis. Her pulse is 96 and regular, with a soft flow murmur and no signs of cardiac failure. On the cause-directed examination, her abdomen is soft with no masses, organomegaly or surgical scars; there is no lymphadenopathy, no dialysis access, and no dermatitis herpetiformis. In summary: this is a patient with clinical signs of iron-deficiency anaemia and no external clue to the source. Given she is 58 and postmenopausal, my leading concern is occult gastrointestinal blood loss, and I would confirm the diagnosis with ferritin and transferrin saturation, screen for coeliac disease, and arrange bidirectional endoscopy." [3] [1]

Discussion — where the examiner takes it next

"Which sign is most specific?" — Koilonychia is the classic specific sign of iron deficiency, though it is late and insensitive; glossitis and angular cheilitis support the diagnosis. The honest framing is that the examination raises the probability but the ferritin and TSAT make the diagnosis [1].

"How would you distinguish this microcytosis from thalassaemia trait?" — "On the count before any fancy test: iron deficiency lowers the red cell count while thalassaemia trait raises it — the Mentzer index (MCV divided by red cell count) is above 13 in iron deficiency and below 13 in trait. Iron studies are normal in trait; if the indices and ethnicity fit, I order haemoglobin analysis with HbA2 rather than prescribing iron." [4] [1]

"What would you do today?" — "Confirm with ferritin, TSAT and CRP; B12/folate; coeliac serology; refer for gastroscopy with duodenal biopsies and colonoscopy given her age and postmenopausal status; start oral iron once daily or alternate days with clear counselling; and recheck her in 4 weeks with a defined response expectation — while making explicit that the endoscopy proceeds regardless of the response." [3].

"Any red flags you'd voice unprompted?" — Two: dysphagia (Plummer-Vinson and post-cricoid carcinoma risk), and the reflex to transfuse — a stable patient with chronic iron deficiency gets iron and a cause hunt, not blood [1] [3].