Scurvy (vitamin C deficiency) — Viva

Q1: Definition and clinical presentation (2 min)

Examiner: A 68-year-old widow presents with bruising on her shins and bleeding gums. She eats only tea and toast. What is your diagnosis, and what is the pathognomonic cutaneous sign?^[1]

Candidate: Scurvy — severe vitamin C deficiency.^[1][3] The pathognomonic cutaneous sign is the corkscrew hair: a twisted, coiled, fragmented hair shaft within a keratin-plugged follicle, found on the upper arms, thighs, and shins. The full tetrad is follicular hyperkeratosis, corkscrew hairs, perifollicular purpura, and bleeding gums.

Q2: Pathophysiology — why does she bleed? (3 min)

Examiner: Walk me through the mechanism. Why does she bleed despite normal clotting?^[1]

Candidate: Vitamin C is the cofactor for prolyl-4-hydroxylase and lysyl hydroxylase, which hydroxylate proline and lysine in the collagen alpha-chain.^[3] Hydroxylation stabilises the triple helix (it needs roughly 100 hydroxyproline residues to stay intact at 37°C) and permits lysine cross-linking. Without ascorbate, collagen is under-hydroxylated, unstable, and poorly cross-linked, so capillary basement membrane and perivascular collagen weaken mechanically. Platelet number, platelet function, PT, APTT, and von Willebrand factor are all normal — the bleeding is mechanical, not haematological. That is why the bleeding time may be slightly prolonged but the coagulation screen is normal.

Q3: Investigations (2 min)

Examiner: How would you confirm the diagnosis?^[1]

Candidate: Clinically — the tetrad plus a dietary risk factor. Plasma ascorbic acid under 11.4 micromol/L confirms it, but the assay is not always available and the sample oxidises rapidly on light and warmth.^[3] The 24 to 48 hour response to ascorbic acid is itself diagnostic and is the pragmatic gold standard. I would send FBC (anaemia, normal platelets), PT and APTT (normal), iron studies, folate, and B12 to exclude mimics and quantify co-deficiencies. In a limping child I would add knee radiographs for the Frankel white line and sub-periosteal haemorrhage.

Q4: Management (3 min)

Examiner: She also drinks alcohol heavily. What must you give before refeeding, and what is the treatment regimen?^[1]

Candidate: Parenteral thiamine 100 mg IV or IM before any carbohydrate load — to prevent Wernicke encephalopathy. I would also monitor phosphate, magnesium, and potassium during refeeding. The scurvy regimen is oral ascorbic acid 500 mg three times daily — that is 300 to 1000 mg daily — for one week, then 100 mg daily maintenance.^[1] I would replace iron, folate, and B12 as indicated, arrange dietetic and social work input for the tea-and-toast pattern, and give written dietary advice emphasising citrus, peppers, kiwi, strawberries, and broccoli.

Q5: Complications and prognosis (2 min)

Examiner: What is the prognosis, and what are the complications if untreated?^[1]

Candidate: The prognosis is excellent — symptom resolution within 48 to 96 hours on 1 g/day in children, clear improvement within the first days in adults with full skin resolution by about two weeks, and anaemia correcting within a month with iron and folate, and corkscrew hairs grow out over 1 to 3 months.^[1] Full recovery is the rule. Untreated, complications include severe haemorrhage, poor wound healing with reopening of old wounds, immunosuppression with infection susceptibility, progressive anaemia, and — in advanced paediatric disease — pulmonary hypertension and death.^[2] The disease is completely curable and almost entirely preventable with a single daily portion of fruit or vegetables.

References3ShowHide

1. [1]Toscano F, et al. Scurvy, all the faces you can see: our experience and review of the literature. Italian journal of pediatrics, 2025.PMID 40437614
2. [2]Reikersdorfer KN, et al. The Troubling Rise of Scurvy: A Review and National Analysis. JAAOS Global research & reviews, 2024.PMID 39018570
3. [3]Kinlin LM, Weinstein M. Scurvy: old disease, new lessons. Paediatrics and international child health, 2023.PMID 37795755