Subadult health and disease in prehistoric Tonga, Polynesia.

This article focuses on the differential diagnosis of pathologic lesions recorded on the limbs and crania of 17 subadults from two pre-European burial mounds in Tonga, western Polynesia. All affected subadults were between the ages of 6 months and 3 years at death. The lesions described consist primarily of subperiosteal new bone deposition on the limbs and endocranial surface. However, the presence of cribra orbitalia in a number of individuals indicates concurrent iron-deficiency anaemia. A differential diagnosis of haematogenous osteomyelitis, congenital syphilis, yaws, scurvy, hypervitaminosis A, trauma, Caffey's disease, and iron-deficiency anaemia is discussed. It was concluded that the most likely cause for the lesions observed is a synergistic relation between infection (weanling diarrhoea, yaws) and metabolic disease (scurvy and possibly hypervitaminosis A). Trauma is not ruled out as contributing to the development of some pathologic lesions. It is concluded that, in the Pacific Islands at least, multiple causes for skeletal pathology in subadults should be considered rather than a single aetiology.