A child in India is diagnosed with Bitot's spots on the temporal conjunctiva. According to WHO grading of Vitamin A Deficiency (VAD) in xerophthalmia, this is classified as:
- A XN (night blindness)
- B X1B (Bitot's spots) ✓
- C X1A (conjunctival xerosis)
- D X2 (corneal xerosis)
Correct answer: B. X1B (Bitot's spots)
Explanation
WHO classification of xerophthalmia: XN = night blindness; X1A = conjunctival xerosis; X1B = Bitot's spots (triangular, foamy, white patches on temporal bulbar conjunctiva); X2 = corneal xerosis; X3A = corneal ulceration/keratomalacia involving <1/3 cornea; X3B = keratomalacia involving ≥1/3 cornea; XS = corneal scar; XF = xerophthalmic fundus. X1B (Bitot's spots) is considered a public health problem indicator when prevalence exceeds 0.5% in children 6-71 months. It indicates chronic deficiency but is potentially reversible with Vitamin A supplementation.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.