A Rare Case of Reversible Pulmonary Hypertension Phenotype in a Child with Scurvy: Aetiologies Insights

<b>Background and Clinical Significance:</b> Scurvy, caused by chronic vitamin C deficiency, is re-emerging in Western countries, particularly among pediatric patients with highly selective diets. While its musculoskeletal and mucocutaneous manifestations are well-known, its association with pulmonary arterial hypertension (PAH) is rare and poorly understood. Ascorbic acid and iron are essential cofactors for prolyl hydroxylases (PHD), which regulate Hypoxia-Inducible Factors. Their combined deficiency may trigger a "pseudohypoxic" state, leading to pulmonary vascular remodeling and vasoconstriction. <b>Case Presentation</b><b>:</b> A 30-month-old female presented with a one-month history of limping, lower limb pain, and gingival hypertrophy. Dietary history revealed an almost exclusive cow's milk-based intake. Physical examination showed diffuse petechiae, pallor, and right knee edema. Laboratory findings confirmed scurvy (undetectable vitamin C), severe iron-deficiency anemia (Hb: 72 g/L; ferritin: 22 mcg/L; RDW: 30%), folate deficiency, and hyperhomocysteinemia. Notably, elevated copper and vitamin B12 levels suggested a state of metabolic dysregulation. Echocardiography revealed moderate PAH phenotype (estimated sPAP: 47-50 mmHg) and a hyperdynamic contractility. A "perfect storm" mechanism was hypothesized, involving iron-ascorbate-dependent PHD impairment, high-output state, and oxidative-stress-induced hepcidin dysregulation (suggested by elevated copper). Following intravenous vitamin C and multivitamin supplementation, pulmonary pressures normalized within one week. <b>Conclusions:</b> PAH phenotype in scurvy represents a reversible metabolic disruption of pulmonary vascular tone rather than a structural disease. This case underscores the synergistic role of vitamin C, iron, and folate in vascular homeostasis. Clinicians should maintain high suspicion for scurvy in children with selective diets and unexplained PAH, as nutritional restoration is curative.