وصف
Rickets is a childhood disease where your child’s bones are too soft, causing their bones to warp, bend and break more easily. It’s typically caused by a lack of vitamin D, but in rare cases, is caused by an underlying genetic disorder.Rickets is different from osteomalacia, which is a similar condition seen in adults. The difference between the two is that rickets happens only in children because their bones are still growing, which causes the classic symptom of bowed or bent bones. Adults’ bones have already finished growing and they don’t have this symptom (unless they had untreated rickets as a child).While rickets is a treatable and often curable disease, it’s important to treat it as soon as possible. When not treated, milder cases of rickets can result in long-term bone that can keep bones from growing properly. Severe cases that aren’t treated can lead to seizures, heart damage and death.
ملخص
- Vitamin D, a sunshine vitamin and steroid prohormone, is critical for calcium homeostasis and bone health, especially in children. Rickets, a disorder of growing children, results from inadequate mineralization of the growth plate, leading to deformities and impaired bone growth. Rickets is broadly classified into vitamin D deficiency rickets (nutritional) and vitamin D resistant/refractory rickets, with nutritional rickets being the more prevalent form.
- Nutritional rickets is typically caused by vitamin D deficiency, stemming from factors like insufficient dietary intake, limited sun exposure, preterm birth, low birth weight, and certain medications. Vitamin D resistant rickets can be due to chronic hepatic or renal diseases, hypophosphatemia (familial or renal tubular acidosis), or vitamin D dependent rickets, which includes types I and II involving hydroxylase deficiencies or organ resistance to vitamin D. Calcipenic rickets arises from calcium and vitamin D deficiencies, while phosphopenic rickets is associated with deficient phosphate intake, prematurity, total parenteral nutrition, and certain genetic conditions like Fanconi syndrome.
- Calcipenic rickets presents with muscle weakness, bone pain, and tetany, along with low serum calcium and phosphorus and elevated alkaline phosphatase. Phosphopenic rickets typically lacks muscle weakness and bone pain but still exhibits low serum phosphorus and elevated alkaline phosphatase, while serum calcium remains normal. Parathormone is elevated in calcipenic rickets but normal in phosphopenic rickets, and osteopenia/osteoitis fibrosa is present only in calcipenic rickets.
- Risk factors for vitamin D deficiency include living in northern latitudes, wearing clothing that covers most of the skin, cultural avoidance of sunlight, darker skin pigmentation, vegetarian diets, prolonged breastfeeding without vitamin D supplements, and chronic calcium deficiency. Vitamin D, derived from sunlight and dietary sources, undergoes hydroxylation in the liver and kidney to form active metabolites crucial for calcium and phosphorus absorption and bone mineralization. The daily vitamin D requirement ranges from 400 to 600 international units, and deficiency can lead to rickets in children and osteomalacia in adults.
- Vitamin D status is assessed by measuring 25-hydroxy D levels, with severe deficiency indicated by levels below 5 ng/mL. Excessive vitamin D levels, above 100 ng/mL, can cause toxicity, leading to hypervitaminosis D. The pathophysiology of rickets involves reduced calcium and phosphorus absorption, elevated parathyroid hormone levels, and deficient mineralization of growing bone tissue. Clinical manifestations of rickets include craniofacial changes like craniotabes and frontal bossing, thoracic changes such as rachitic rosary and Harrison's sulcus, and limb deformities like widening of the wrists and ankles and bowlegs.
- Diagnosis of rickets involves identifying typical clinical deformities, characteristic radiological changes at the wrist joint, and biochemical changes such as increased serum alkaline phosphatase and low serum phosphorus. Differential diagnoses should distinguish nutritional rickets from vitamin D resistant or refractory forms. Treatment of nutritional rickets often involves a stress regimen with high-dose vitamin D and calcium supplementation, while prevention involves adequate sun exposure and vitamin D supplementation, especially in preterm infants and rapidly growing children.
- Vitamin D resistant rickets, less common, is associated with systemic and metabolic defects, including familial hypophosphatemia. Diagnosis requires ruling out a response to vitamin D therapy and identifying family history. Treatment involves phosphate supplements and calcitriol, with standard vitamin D therapy avoided due to the risk of hypercalcemia. Hypervitaminosis D is typically iatrogenic, resulting from excessive vitamin D administration. Its clinical manifestations include hypercalcemia, hypercalciuria, and metastatic calcification.
- Management of hypervitaminosis D includes discontinuing vitamin D, reducing calcium intake, and administering calcium chelators and cortisone. Screening for vitamin D deficiency is recommended for individuals exhibiting non-specific symptoms, those in high-risk groups, and those with frequent fractures. Pharmacological doses of vitamin D vary based on age, and calcium supplementation is essential in cases of nutritional rickets. A case study illustrates the presentation, diagnosis, and management of a child with vitamin D deficient nutritional rickets.
نموذج شهادة
حول المتحدثين
Dr.Bharat Parmar
Consultant Radiation Oncologist and Pain and Palliative Care PhysicianYashoda Hospitals
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