A 27-year-old man comes to the emergency department (ED) with unremitting nose bleeding. He had a similar bleeding episode one year ago that was stopped in the ED. He works as a computer programmer and has a sedentary lifestyle. He drinks alcohol on social occasions but does not smoke or use illicit substances. On physical examination, there are several ruby-colored papules on his lips that blanch partially with pressure. Digital clubbing is also present. His abdomen is soft and non-tender. The liver span is 8 cm and the spleen is not palpable. Laboratory results are as follows: Which of the following is most likely responsible for this patient's increased hematocrit?

Question

A 27-year-old man comes to the emergency department (ED) with unremitting nose bleeding.  He had a similar bleeding episode one year ago that was stopped in the ED.  He works as a computer programmer and has a sedentary lifestyle.  He drinks alcohol on social occasions but does not smoke or use illicit substances.  On physical examination, there are several ruby-colored papules on his lips that blanch partially with pressure.  Digital clubbing is also present.  His abdomen is soft and non-tender.  The liver span is 8 cm and the spleen is not palpable.  Laboratory results are as follows:  Which of the following is most likely responsible for this patient's increased hematocrit?

Quizplus · Accepted Answer

This patient most likely has hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome), an autosomal dominant disorder characterized by diffuse telangiectasias (eg, ruby-colored papules that blanch with pressure), recurrent epistaxis, and widespread arteriovenous malformations (AVMs). In hereditary hemorrhagic telangiectasia, AVMs tend to occur in the mucous membranes, skin, and gastrointestinal tract, but may also be present in the liver, brain, and lung. AVMs in the lungs can shunt blood from the right to the left side of the heart, causing chronic hypoxemia, digital clubbing, and a reactive polycythemia. Pulmonary AVMs can also present as massive, sometimes fatal, hemoptysis. (Choice A) Polycythemia vera is a myeloproliferative disorder that typically causes increased production of all 3 blood cell lines and splenomegaly. Telangiectasias and digital clubbing are not present. In addition, the median age for patients with polycythemia vera is 60. (Choice B) Plasma volume loss can cause spurious polycythemia by concentrating red blood cells within the vasculature. The most common causes of decreased plasma volume are diarrhea, vomiting, and poor oral intake. (Choice C) Pulmonary hypertension and polycythemia commonly co-exist. First, polycythemia can cause pulmonary hypertension by increasing blood viscosity within the pulmonary vasculature. Additionally, in patients with chronic hypoxemia, both pulmonary hypertension and polycythemia can result. However, AVMs and pulmonary hypertension are generally not related. (Choice E) Carbon monoxide poisoning decreases the amount of oxygen that can be carried in the blood, and the body compensates by developing a secondary polycythemia. Based on this particular patient's history and presentation, hereditary telangiectasia is a more likely diagnosis. (Choice F) Pulmonary conditions that cause hypercarbia often also cause polycythemia, but it is not the hypercarbia itself that causes the increased red blood cell production. (Choice G) Certain vitamin deficiences (eg, vitamin C, vitamin K) can cause bleeding but are typically not associated with polycythemia or telangiectasias. Educational objective: Patients with hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome) can develop pulmonary arteriovenous malformations associated with hemoptysis and right-to-left shunt physiology. This diagnosis must be entertained in a patient with recurrent nose bleeds and oral lesions.

A 27-Year-Old Man Comes to the Emergency Department (ED) with Unremitting