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Wajeeha Aiman M.D.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:

Overview

Scurvy is a chronic deficiency disease of vitamin C, which is necessary for normal collagen formation in humans. L-ascorbic acid, the scientific name for vitamin c, is derived from the Latin name, scorbutus. Early symptoms of this disease are fatigue, weakness, and sore arms and legs. Without treatment, changes in hair, skin, and gums occur. As scurvy worsens there can be personality changes, poor wound healing and ultimately leading to death due to bleeding or infection. a British physician who described it. Other eponyms include Moeller's disease and Cheadle's disease. In the modern world, scurvy rarely presents in adults, infants and elderly are affected more. Vitamin C, a water soluble vitamin, can easily be destroyed by pasteurization. So bottle-fed babies, not supplemented with adequate vitamins, can easily develop scurvy. For this reason, vitamin C is added to all approved baby formulas. If mothers take an adequate amount of vitamin C, then breast milk is sufficient for the babies need of this vitamin.

Pathophysiology

Physiology

Vitamins are very important for the formation and normal functioning of enzymes that are responsible for multiple processes in the human body. Ascorbic acid is necessary for accelerating amidation reactions and hydroxylation in normal collagen synthesis. The hydroxylation of lysine and proline residues occurs in endoplasmic reticulum and leads to hydroxylysine and hydroxyproline, respectively. Enzymes responsible for these reactions are lysyl hydroxylase and prolyl hydroxylase. For healthy skin, bone, muscles, cartilage, blood vessels, and other connective tissues, the primary structure collagen protein is required with a proper synthesis and normal functioning.

Pathogenesis

Defective collagen leads to abnormalities in all connective tissue areas. In blood vessels, defective connective tissue leads to fragile capillaries and causes bruising, abnormal bleeding, and internal hemorrhages. Similarly, teeth loosen, bones are easily breakable, recurrence of fractures, and poor wound healing. Scurvy is fatal if left untreated.

Genetics

Scurvy is not a nutritional disorder exclusively. Some studies have shown evidence of genetic involvement. In the recent European history, the geographic variability of the higher mortality rate during famine and scurvy episodes can be explained by the genetic polymorphism of HFE and haptoglobin (Hp). HFE gene mutations occur in a genetic disorder, hereditary hemochromatosis, predominantly affects men and causes iron overload with a reduction in the stability of vitamin C. Hemochromatosis is associated with mutations in C282Y and H63D. Hypoascorbemia is the true genetic disease defined as an "inborn error of metabolism", due to the absence of an active liver enzyme, L-gluconolactone oxidase. This is the enzyme used in the final step of converting glucose to ascorbic acid, therefore it blocks the endogenous formation of this important vitamin in man. The absence of this enzyme is due to defected gene or hereditary lack of the gene. This disease is similar to other genetic metabolic disorders like alkaptonuria, galactosemia, albinism, and many others.

Associated Conditions

Scurvy is associated with many nutritional deficiencies.

• Malnutrition
• Pellagra
• Beriberi
• Alcohol abuse
• Restricted diet due to allergies or any other cause
• Crohn's Disease
• Ulcerative colitis
• Celiac disease
• Smoking and other illicit drugs use
• Hemochromatosis
• Chemotherapy

Gross Pathology

Lack of vitamin C leads to dermatological changes like gingival swelling, poor wound healing, ecchymosis, petechiae, loose teeth, and hyperkeratosis. Nails show koilonychia and splinter hemorrhages. Lower extremities can develop "woody edema" due to gravity dependency. Rheumatological findings are hemarthrosis and subperiosteal hemorrhage. Osseous pathology with distorted endochondral bone formation leads to fragile bones causing fractures. Ocular symptoms like dry eyes, scleral icterus, and subconjunctival hemorrhages can also occur. Alopecia and bleeding is also common.

Microscopic Pathology

Microscopically, it is similar to clinical manifestations. On punch biopsy, scurvy shows dilated hair follicles, perifollicular hemorrhage without inflammation, and corkscrew hairs causing keratin plugging. Fundoscopy shows papilledema, cotton wool spots and flame hemorrhages, retrobulbar bleeding can also occur.