A 5-Year-Old Boy Is Brought to the Emergency Department for Evaluation

A 5-year-old boy is brought to the emergency department for evaluation of a progressive rash that started 2 days ago. The rash began on the face and progressed to the trunk and extremities. Over the past week, he has had a runny nose, a cough, and red, crusty eyes. He immigrated with his family from Turkey 3 months ago. His father and his older brother have Behçet disease. Immunization records are unavailable. The patient appears irritable and cries during the examination. His temperature is 40.0°C (104°F) . Examination shows generalized lymphadenopathy and dry mucous membranes. Skin turgor is decreased. There is a blanching, partially confluent erythematous maculopapular exanthem. Examination of the oral cavity shows two 5-mm aphthous ulcers at the base of the tongue. His hemoglobin concentration is 11.5 g/dL, leukocyte count is 6000/mm3, and platelet count is 215,000/mm3. Deficiency of which of the following is associated with a high rate of complications from this patient's condition?

A) Vitamin A
B) Vitamin B₆
C) Vitamin B₁₂
D) Vitamin D
E) Vitamin E
F) Vitamin K