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Nursing QUESTION #9262
Question 1
A 14-month-old child is brought with refusal to walk, irritability, bony swellings at costochondral junctions (rachitic rosary), and Harrison's sulcus. X-ray shows cupping and fraying of metaphyses. The MOST likely diagnosis and its PRIMARY pathophysiology is:
  • Scurvy; vitamin C deficiency causing impaired collagen synthesis
  • Nutritional Rickets; vitamin D deficiency causing impaired calcium and phosphate metabolism✔️
  • Osteogenesis imperfecta; collagen type I defect
  • Congenital hypothyroidism; thyroid hormone deficiency
Correct Answer Explanation

Nutritional Rickets — deficiency of Vitamin D leading to impaired bone mineralization.

Pathophysiology:

\[\downarrow \text{Vit D} \Rightarrow \downarrow \text{Ca}^{2+}\,\text{absorption (gut)} \Rightarrow \downarrow \text{Serum Ca}^{2+} \Rightarrow \uparrow \text{PTH} \Rightarrow \downarrow \text{Phosphate (renal loss)} \Rightarrow \text{Impaired mineralization}\]

Clinical features:

  • Rachitic rosary: Bony swellings at costochondral junctions
  • Harrison's sulcus: Horizontal groove along lower chest (diaphragm pull)
  • Craniotabes: Ping-pong ball sensation (skull)
  • Bossing: Frontal bossing
  • Widened wrists/ankles
  • Bow legs (genu varum) or knock knees
  • Delayed dentition, hypocalcemic tetany

Labs: \(\downarrow\) Ca, \(\downarrow\) PO₄, \(\uparrow\) ALP (markedly), \(\uparrow\) PTH, \(\downarrow\) 25-OH Vitamin D

X-ray: Cupping, fraying, splaying of metaphyses (especially distal radius)

Treatment: Vitamin D \(1000{-}5000\,\text{IU/day}\) for 3 months + calcium supplementation.