Skorbut (Scurvy)

01Pathophysiology

Vitamin C is an essential cofactor for prolyl hydroxylase and lysyl hydroxylase, the enzymes responsible for hydroxylation of proline and lysine residues during collagen synthesis. Without adequate ascorbic acid, the resulting collagen molecules are structurally unstable and cannot form proper triple-helix configurations. This defective collagen is the central mechanism behind virtually every manifestation of scurvy: blood vessels become fragile (leading to hemorrhage), wound healing stalls, and connective tissue throughout the body weakens.

The bleeding tendency in scurvy is not a coagulopathy in the traditional sense. Platelet count and coagulation cascades (PT, PTT) are typically normal. Instead, the hemorrhagic manifestations arise from loss of vascular structural integrity due to defective collagen in capillary basement membranes. This is why the bleeding pattern is characteristically perivascular: perifollicular petechiae around hair follicles, gingival hemorrhage, and subperiosteal bleeding.

Vitamin C also functions as a potent antioxidant and plays a role in iron absorption (by reducing ferric iron to ferrous iron in the gut) and in the synthesis of carnitine and certain neurotransmitters (norepinephrine, serotonin). This explains the early constitutional symptoms of fatigue and irritability that precede the more dramatic hemorrhagic signs. Prolonged deficiency can contribute to iron-deficiency anemia both through impaired absorption and through chronic blood loss from widespread capillary hemorrhage.

In children, the skeletal findings are prominent because vitamin C is critical for osteoid formation. Growing bones require constant collagen deposition; when this fails, the periosteum separates from underlying bone due to subperiosteal hemorrhage, and the zone of provisional calcification becomes irregular. The child presents with bone pain, pseudoparalysis (refusal to move limbs), and a characteristic frog-leg position.

02Classification and Clinical Manifestation

Clinical Manifestation

03Diagnostic Workup

In practice, scurvy is overwhelmingly a clinical and dietary diagnosis. The classic exam vignette presents a patient with a clearly inadequate diet (alcoholic male living alone, a child on restrictive or unusual diet, an elderly person eating only tea and toast) combined with the hallmark physical findings of perifollicular hemorrhage and corkscrew hairs.

The best initial test on an exam is serum ascorbic acid level, which is quick and accessible. However, serum levels fluctuate with recent intake and do not reliably reflect total body stores. The leukocyte ascorbic acid level (buffy coat assay) is the most accurate measure of tissue-level vitamin C status, but it is seldom ordered in real-world practice and is primarily a test-taking distinction.

A critical diagnostic reasoning point: when a vignette describes a bleeding patient with normal PT, PTT, and platelet count, this should immediately trigger you to think beyond coagulation factor deficiencies and thrombocytopenia. The combination of mucocutaneous bleeding plus normal coagulation studies plus a poor diet points directly to scurvy. Test-writers use the normal coagulation panel as a deliberate clue to steer you away from hemophilia, von Willebrand disease, and ITP.

In pediatric cases, the radiographic findings are high-yield. The Frankel line (a dense white line at the metaphysis representing calcified but non-resorbed cartilage) and the Trummerfeld zone (a lucent band just proximal to it representing inadequate osteoid) together create a characteristic layered appearance. The Wimberger ring sign refers to a sharply demarcated sclerotic ring around the epiphyseal ossification center. These findings, combined with subperiosteal hemorrhage, are pathognomonic in the right clinical context.

04Management and Treatment

Acute treatment centers on prompt oral ascorbic acid replacement. The typical adult regimen is 500 to 1000 mg per day divided into two or three doses, continued for a minimum of one month. Clinical improvement is rapid: fatigue and malaise begin to resolve within 24 to 48 hours, and gingival symptoms and skin hemorrhages start improving within one to two weeks. Complete healing of dermatologic and mucosal findings usually takes one to three months.

For the "next best step" logic on an exam, the answer is almost always start oral vitamin C supplementation. Parenteral (IV) ascorbic acid is reserved for patients who cannot take oral medications (severe malabsorption, critically ill patients, or those with gastrointestinal pathology preventing absorption). Exam questions rarely test parenteral dosing; the oral route is the expected answer.

Dietary counseling is a required component of management and is often tested as part of the long-term plan. Even after symptoms resolve with supplementation, the patient must be educated on maintaining adequate vitamin C intake through diet to prevent recurrence.

When concurrent iron-deficiency anemia is present, both vitamin C and iron should be supplemented simultaneously. Vitamin C reduces ferric iron ($F{e}^{3+}Fe^\{3+\}$) to ferrous iron ($F{e}^{2+}Fe^\{2+\}$) in the duodenum, facilitating absorption. This biochemical synergy is testable.

There are no notable drug contraindications to standard vitamin C supplementation at therapeutic doses. At very high doses (>2 g/day), there is a theoretical increased risk of oxalate nephropathy and kidney stones in predisposed individuals, but this is rarely relevant at the doses used for scurvy treatment. Patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency should avoid extremely high intravenous doses, as this can provoke hemolysis, though this is an uncommon testing scenario.

05Differential Diagnosis and Distractors

06Traps and High-Yield Pearls

The most common trap on scurvy questions is not recognizing the dietary history as the critical clue. Vignette writers will often bury a line about the patient's diet ("eats only canned food," "hasn't eaten fresh produce in months," "drinks alcohol daily and eats minimally") among a long list of presenting complaints. Students who skip over this social history element and focus only on the bleeding will be tempted to pick a coagulopathy or platelet disorder, especially since scurvy appears infrequently on exams and is not top of mind.

Another common pitfall is confusing Scorbutic rosary with Rachitic rosary. Both produce costochondral beading in children, but the underlying mechanisms and associated findings are entirely different. The exam may present both as answer choices for a child with skeletal abnormalities, and the discriminator is the presence of hemorrhagic findings (scurvy) versus metabolic bone changes with low calcium and elevated alkaline phosphatase (rickets).

In pediatric vignettes, scurvy can be mistaken for child abuse because of the subperiosteal hemorrhage and widespread bruising. The key discriminator is the radiographic pattern (Frankel line, Trummerfeld zone, Wimberger ring sign) combined with dietary history and the absence of inconsistent trauma histories or retinal hemorrhages.

The core competency being tested is threefold: first, recognizing that normal coagulation studies in a bleeding patient should redirect your differential away from factor deficiencies and toward vascular or connective tissue causes; second, linking the clinical findings to a dietary and social history that explains the pathophysiology; and third, understanding that defective collagen synthesis is the unifying mechanism behind all the seemingly disparate manifestations of this disease.