A practical algorithm for polydipsia in children]

There is a lack of consent on a clinical diagnostic work-up for children with polydipsia. This can result in a delay in diagnosis in some children and unnecessary investigations in others. We describe three children who presented with polydipsia. Two of them were diagnosed with psychogenic polydipsia and one with central diabetes insipidus. We discuss the differential diagnosis and relevant clinical signs before going on to propose a clinical diagnostic algorithm that can be used in children with polydipsia. A systematic diagnostic work up for children with polydipsia helps to differentiate between those in whom polydipsia is unlikely to have a somatic cause and those where a water deprivation-test is indicated. A water deprivation test in children is an invasive procedure and should be performed by a paediatric endocrinologist or nephrologist.