Review Question - QID 217733

This patient has been on a 3-month diet of only animal products and has evidence of phrynoderma (enlarged hyperkeratotic hair), lethargy, petechiae, anemia, and normal clotting levels. Given the history and his presentation, this patient most likely has scurvy, which is due to a deficiency of vitamin C.

Scurvy is a condition that is caused by vitamin C deficiency. Vitamin C plays many important roles in the body, ranging from iron absorption to catecholamine metabolism to collagen synthesis. As a result, patients can present with fatigue, poor wound healing, cutaneous manifestations (corkscrew hairs and phrynoderma), and gingivitis. Anemia is not uncommon due to hemorrhage as well as iron and folate deficiencies. Vitamin C is commonly obtained in fruits and vegetables. Hence, adult patients that are at risk for scurvy usually suffer from malnutrition such as patients with cancer, anorexia, cancer, or inflammatory bowel disease, the elderly, as well as those who engage in fad diets. The diagnosis of scurvy is primarily clinical. Patients are treated with daily oral ascorbic acid (100 to 300 mg) until symptoms improve.

Trapani et al. review scurvy in pediatric patients. In high-income countries, the prevalence of pediatric scurvy appears to be quite low, with a national survey revealing deficiency of vitamin C in 1.6% of children between 6 and 11 years. Certain populations are especially vulnerable due to inadequate nutrition (mental, physical, or neurological disabilities), decreased absorption (celiac or Crohn disease), or wasting (iron overload from transfusions in sickle cell disease or thalassemia). There are also increasing cases of normal children with no risk factors who develop deficiency from being “picky” eaters who avoid fruits and vegetables.

Incorrect Answers:
Answer 1: Vitamin A is a fat-soluble vitamin that has roles in immunity, vision, and maintenance of mucosa. It is found in dark leafy greens and carrots. Its deficiency classically presents with night blindness, xerophthalmia (an inability to form tears), phrynoderma, and increased GI, urinary, and pulmonary infections. Despite the patient’s phrynoderma, vitamin A deficiency would not explain the anemia and petechiae.

Answer 2: Vitamin B6 (pyridoxine) is a water-soluble vitamin that becomes a critical coenzyme for key metabolic processes and neurotransmitter synthesis. It is found in beef, chicken, fish, and dark leafy greens. Its deficiency can lead to seizures, anemia, glossitis, nausea, and polyneuropathy. The patient’s diet of animal products would unlikely lead to vitamin B6 deficiency.

Answer 3: Vitamin B7 (biotin) is a water-soluble vitamin that serves as an important carboxylase coenzyme in a variety of metabolic pathways. It is found in egg yolk, wheat, rice, and spinach. Patients with biotin deficiency can develop neurological (e.g., neuropathy, depression, and hallucinations) and dermatological (e.g., dermatitis and alopecia) symptoms. While heavy consumption of raw egg whites (containing biotin-binding avidin) may cause biotin deficiency, this patient consumes cooked eggs.

Answer 5: Vitamin K is a lipid-soluble vitamin that plays an important role in the synthesis of clotting factors II, VII, IX, and X as well as anticoagulant proteins C and S. It is found in dark leafy greens. Patients with vitamin K deficiency develop problems with coagulation and have bleeding with minor trauma. The clotting labs usually show elevated prothrombin time (PT) and activate partial thromboplastin time (PTT). This patient’s PT and PTT are within the normal range.

Bullet Summary:
Scurvy is a disease of vitamin C deficiency and patients can present with fatigue, anemia, poor wound healing, gingivitis, petechiae, and corkscrew hairs.