Milk intolerance in children with persistent sleeplessness: a prospective double-blind crossover evaluation.

From July 1986 to July 1988, 146 children less than 5 years of age were referred by their physicians to our university sleep clinic for continual waking and crying during sleep hours. For 85 children (58.2%), the sleeplessness was attributed to inappropriate sleep habits. For 17 children (11.6%), no explanation was found for the sleep difficulties in spite of an extensive workup. Their median age at referral was 13.5 months (range 2.5 to 29 months). Their persistent sleeplessness was tentatively attributed to an undiagnosed intolerance to cow's milk. Cow's milk was excluded from their diet. In 15 children sleep normalized after 5 weeks (range 4 to 6 weeks). As seen from the parents' logs, the median time needed by the children to fall asleep decreased from 15 minutes (range 15 to 60 minutes) to 10 minutes (range 10 to 15 minutes, P = .001). The number of complete arousals decreased from 5 (range 1 to 12) to less than 1 per night (range 0 to 2) (P = .001). Total sleep time per 24 hours increased from 5.5 hours (range 3 to 8.5 hours) to 13.0 hours (range 10 to 14.5 hours, P = .001). Sleep normalized in one child who continued to receive no cow's milk only after the hydrolyzed hypoallergenic diet was discontinued. In every child, a double-blind crossover challenge was conducted involving a control diet containing no cow's milk and a diet containing cow's milk. The challenge induced the reappearance of insomnia and agitated behavior in all except one child. The child's initial sleep difficulties were retrospectively attributed to inappropriate sleep habits.(ABSTRACT TRUNCATED AT 250 WORDS)