Vitamin A deficiency with conjunctival xerosis and Bitot's spots

**Definition:** Generalised conjunctival xerosis suggests advanced vitamin A deficiency. The entire conjunctiva appears dry, roughened, and corrugated, sometimes skin-like. In some individuals keratin and saprophytic bacilli accumulate on the xerotic surface, giving it a foamy or cheesy appearance. Such lesions are known as Bitot's spot. With treatment active conjunctival xerosis and Bitot's spot begin to resolve within 2-5 days. Most will disappear within 2 weeks, though a significant proportion of temporal lesions may persist, in shrunken form, for months.