Scurvy is well-defined acute manifestation of Vitamin C deficiency, though mild or sub clinical deficiency states may present with impaired wound healing, bleeding gums, mild anemia and increased susceptibility for infections.
Vitamin C or Ascorbic acid is a water-soluble vitamin, essential for synthesis of — a) normal collagen by incorporating proline and hydroxyproline, and b) chondroitin sulphate — a component of inter cellular matrix required for epithelial integrity and wound healing. It also facilitates – c) iron absorption, d) folate metabolism (conversion of folic acid into folinic acid) and e) elimination of toxic free radicals (anti-oxidant).
Being a water-soluble vitamin, it is not stored in body and rapidly excreted in urine. Breast feeding is an adequate source of Vitamin C in early infancy. Although widely distributed in many food items (except meat), it is extremely heat-labile, rapidly inactivated on cooking and extrudes in cooking-water.
Etiology of Vitamin C deficiency
Scurvy is usually precipitated by sudden increase in Vitamin C requirements due to infections, acute febrile illnesses, diarrhea etc. in children with sub clinical dietary deficiency e.g. in PEM or top-feeding (rare in breast-fed). Wrong cooking practices e.g. over boiling of vegetables in excess water or throwing the excess cooking-water are important causes of dietary Vitamin C deficiency.
Clinical manifestations of Vitamin C deficiency: Scurvy usually presents in late infancy or in toddlers, following an infective episode e.g. diarrhea or viral infection in malnourished children. A typical case present with —
RDA: 30-40 mg/day (Higher in infections e.g. fever, diarrhea)
— Richest source: Amla (600 mg)
— Citrus Fruits: Guava (212), orange, lemon, pineapple
— Vegetables: Cabbage (124), tomato, green vegetables.
— Germinated pulses
— Non-veg foods e.g. Liver and kidneys (not in meat)
Functions: Essential for Collagen formation, Wound healing and epithelial integrity, Facilitate iron absorption and folate metabolism, Anti-oxidant effect,
Vitamin C deficiency states:
• Typical: Scurvy
• Others: poor wound healing, anemia, recurrent infections
a) Skeletat signs:
• Pseudoparalysis -severe tenderness and restricted limb movements with pithed-frog posture
• Scorbutic rosary – tender, sharp, nodular bleeding at costochondral junctions, due to subluxation.
b) Ski nimucosal signs:
• Swollen, purple, bleeding gums
• Petechial/ecchymotic hemorrhages over skin (perifollicular) and mucus membranes. Severe GIT or intracranial bleeds are rare.
c) Mental changes in Vitamin C deficiency:
• Apprehensive facial appearance
• Extreme irritability or apathy
d) Signs of sub clinical
• Poor wound healing
• Moderate dimorphic anemia
• Increased susceptibility for infections
Diagnosis of Vitamin C deficiency
It depends on the following —
a) Suggestive clinical features with history of precipitating event e.g. fever or diarrhea;
b) Characteristic radiological finding, best seen at the end of long bones at knee joint & include —
i) Ground-glass appearance of the shaft and epiphysis due loss of trabecular pattern,
ii) Thinning or Penciling of cortex with sharply outlined epiphyseal ends,
iii) Wimberger’s ring sign- Ground-glass appearance of epiphyseal centers, surrounded by a white ring of compressed collagen,
iv) White line of Frankel – a thick, irregular, transverse, white line at epiphyseal ends due to thickened provisional zones of calcification.
v) Tummeifeldt’s zone of rarefaction – a narrow zone of metaphyseal raref action proximal to Frankel’s line, due to atrophy of sub-epiphyseal cortex.
vi) Angle sign – a triangular, rarefied, lateral defect proximal to Frankel’s line, representing early stage of the zone of rarefaction.
vii) Corner sign or Pelican spur – a lateral spur-like growth of Frankel’s line, due to compression of soft shaft.
viii) Lifting or separation of periosteum from the cortex due to sub-periosteal hematoma. Actual hematomas are visible only after 1-2 weeks of illness as enveloping-shell appearance, due to calcification.
c) Bwchemwal diagnosis is required only in sub clinical cases, based on low ascorbic acid levels in a buffy coat (WBCs) sample of oxalate blood (Normal: 25- 40 mg/dl). A level of zero in this layer indicates scurvy, even without clinical signs. Plasma ascorbic acid levels are unreliable.
DID: Scorbutic bony lesions need to be differentiated from other cases of pseudoparalysis e.g. — a) osteomyelitis/septic arthritis, b) transient synovitis, c) trauma, d) congenital syphilis and e) leukemic bone involvement.
Scorbutic rosary is different from rachitic rosary as it is tender and has sharper margins vs. rounded contour of the rachitic beading.
Treatment of Vitamin C deficiency
Vitamin C therapy (P0 500 mg/day for a week) is highly effective with dramatic clinical recovery within 24-48 hours, though radiological improvement may take many weeks. Recurrence must be prevented by adequate diet and therapeutic supplementation (100 mgI day) for many weeks.
Prevention of Vitamin C deficiency includes nutritional counseling, correct cooking practices and Vitamin C supplementation in lactating mothers, top-fed infants & during acute infective illnesses.