Clinical characteristics of vitamin A responsive and nonresponsive Bitot's spots.

We examined and followed up 59 patients with conjunctival xerosis with a without classic Bitot's spots. Of these, 50 were responsive and nine were unresponsive to vitamin A. Despite a recent World Health Organization classification suggesting otherwise, all cases appeared to represent the same process. In preschool children, the presence of the Bitot's spots on both sides of the corneoscleral limbus or in association with night blindness or punctate keratopathy suggests active vitamin A deficiency. Pigmentation and wrinkling were not useful diagnostic criteria and lesions isolated to the nasal corneoscleral limbus suggested a different diagnosis. At least some cases of nonresponsive conjunctival xerosis and Bitot's spots were probably sequelae of past vitamin A deficiency.