Vitamin A toxicity presenting as bone pain

Abstract

A 4-year-old boy presented with severe bone pains, refusal to walk, diffuse bony swelling of forelimbs, skin changes and abdominal pain, with symptoms evolving over 6 weeks. Blood screening tests were normal except for raised aspartate aminotransferase (AST). Radiographs revealed thickened periosteum, widening of the diaphyses of long bones and lifted periosteum in mid-shaft of ulnae and right femur. Skeletal scintigraphy showed a high uptake of radionuclide at clinically affected and unaffected sites, suggestive of multifocal osteoblastic skeletal lesions. After repeated enquiries, his parents admitted to giving him massive doses of preformed vitamin A for over 3 months as ‘health tablets’. Surprisingly, he did not have overt liver disease typically found with much smaller doses, although the dermal changes and musculoskeletal pathology were florid. He made a full clinical recovery within 2 months of cessation of vitamin A.