Clinical Characteristics of Pediatric Patients with Congenital Erythrocytosis: A Single-Center Study.

Although congenital erythrocytosis (CE), an inherited disorder, impairs pediatric quality of life, physicians often overlook high hemoglobin (Hgb) levels and its symptoms due to lack of knowledge of age-adjusted pediatric Hgb levels and CE's rarity. In a retrospective, single-center study, data from hospital records of pediatric patients diagnosed with CE were evaluated. Twenty-six patients from 25 families (80.8% male) had been diagnosed with CE in 20 years, at a mean age of 14.9 ± 2.8 years (8.3-17.8) and with a mean Hgb level of 17.36 ± 1.44 g/dL (14.63-22.1). No serum erythropoietin levels exceeded the reference levels. Although the most common symptom was headache (85%), 38% of patients presented with at least one gastrointestinal symptom (e.g., nausea, vomiting, abdominal pain, and rectal bleeding), and 54% exhibited plethora. No patient had leukocytosis, thrombocytosis, mutation; capillary oxygen saturation, venous blood gas analysis, and Hgb electrophoresis revealed no abnormalities. While 34.6% of patients had family histories of CE, 42.3% had 15-45-year-old relatives who had experienced myocardial infarction, stroke, and/or sudden death. Aspirin was routinely prescribed, and phlebotomy was performed when hyperviscosity symptoms were present. To detect CE, physicians should consider age-adjusted normal Hgb levels in children. Pediatric patients with CE may also present with gastrointestinal symptoms. Although no thrombotic episode occurred among the patients, their family histories included life-threatening thrombotic episodes, even in adolescents.