The development of hypophosphataemic osteomalacia with myopathy in two patients with HIV infection receiving tenofovir therapy

We report two cases in which osteomalacia developed in patients on tenofovir-containing highly active antiretroviral therapy (HAART) in the context of Fanconi syndrome with hypophosphataemia. Bone pain was the presenting feature and myopathy followed in one case. Disability was reversed with withdrawal of the drug and with mineral supplementation. The cases highlight the importance of considering the diagnosis of osteomalacia in patients treated with tenofovir. A possible association with incipient acute renal failure, particularly during nonsteroidal anti-inflammatory drug (NSAID) use, needs further investigation.     

Disproportionate growth following long-term growth hormone treatment in short children with X-linked hypophosphataemia

Abstract Three short prepubertal children with X-linked hypophosphataemia were treated with 1 IU recombinant human growth hormone (rhGH)/kg per weck sc in addition to calcitriol and phosphate supplementation over a period of 3 years. Improvement of height standard deviation score (SDS) ranged from 1.0–1.7 SD based on an increase in sitting height of 1.5–2.9 SD, whereas subischial leg length improved only slightly by 0.3–0.9 SD. In all three patients, renal phosphate threshold concentration increased slightly and transient hyperparathyroidism was noted.Conclusion Treatment of stunted children with X-linked hypophosphataemia is effective in improving growth velocity, but appears to aggravate the pre-existent disporportionate stature of such children.     

Life-threatening hypophosphataemia in a cirrhotic patient with jaundice

We report the case of a 51-year-old patient with a history of liver cirrhosis, who presented with jaundice (total bilirubin 50 mg/dl [855 µmol/l], direct bilirubin 20 mg/dl [342 µmol/l]) and life-threatening hypophosphataemia (serum phosphate 0.5 mg/dl [0.16 mmol/l]), accompanied by inappropriate phosphaturia. The patient also manifested hypouricaemia (serum uric acid 1.7 mg/dl [101 µmol/l]) with renal uric acid wasting and renal glycosuria. This generalized proximal tubular defect may occasionally be seen in deeply jaundiced patients. Therefore, serum phosphate levels should be closely monitored in these patients.     

Diagnosis and management of unusual dental abscesses in children

Although the majority of dental abscesses in children originate from dental caries or trauma, a few are associated with unusual conditions which challenge diagnosis and management. Recent research findings have shed light on these unusual entities and greatly improved understanding of their clinical implications. These conditions include developmental abnormalities such as dens invaginatus in which there is an invagination of dental tissues into the pulp chamber and dens evaginatus in which a tubercle containing pulp is found on the external surface of a tooth crown. In addition, inherited conditions which show abnormal dentine such as dentine dysplasia, dentinogenesis imperfecta, and osteogenesis imperfecta predispose the dentition to abscess formation. Furthermore, 'spontaneous' dental abscesses are frequently encountered in familial hypophosphataemia, also known as vitamin D-resistant rickets, in which there is hypomineralization of dentine and enlargement of the pulp. In addition to developmental conditions, there are also acquired conditions which may cause unusual dental abscesses. These include pre-eruptive intracoronal resorption which was previously known as 'pre-eruptive caries' or the 'fluoride bomb'. In addition, some undiagnosed infections associated with developing teeth are now thought to be the mandibular infected buccal cysts which originate from infection of the developing dental follicles. In the present paper, these relatively unknown entities which cause unusual abscesses in children are reviewed with the aim of updating the general practitioner in their diagnosis and management.     

Hereditary hypophosphataemic rickets: report of a family from the Indian subcontinent

Nutritional deficiency continues to be an important cause of rickets in the underdeveloped and developing parts of the world. In the western hemisphere, predominantly non-nutritional forms of rickets and osteomalacia are now seen. In this report we discuss a family with X-linked hypophosphataemic rickets from the Kashmir region of the Indian subcontinent (which is an uncommon entity here).