M. Gorky Donetsk National Medical University Department No. 2 of Pediatrics Head of the Department Dr. Churilina A. V., Ph. D. Rickets icon

M. Gorky Donetsk National Medical University Department No. 2 of Pediatrics Head of the Department Dr. Churilina A. V., Ph. D. Rickets




НазваM. Gorky Donetsk National Medical University Department No. 2 of Pediatrics Head of the Department Dr. Churilina A. V., Ph. D. Rickets
Дата19.09.2012
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M.Gorky Donetsk National Medical University Department No. 2 of Pediatrics Head of the Department Dr. Churilina A.V., Ph.D. RICKETS

  • Associate professor Masyuta D.I.


Rickets is a disease of growing organism, which appears as a result of polyhypovitaminosis with primary insufficiency of vitamin D, that leads to disturbances in metabolism of phosphorus and calcium and processes of ossification wild changes of organs and systems function.

  • Rickets is a disease of growing organism, which appears as a result of polyhypovitaminosis with primary insufficiency of vitamin D, that leads to disturbances in metabolism of phosphorus and calcium and processes of ossification wild changes of organs and systems function.

  • Rickets is a disease of children of first two years.





Vitamin D metabolism.









Its antirachitic functions include

  • Its antirachitic functions include

    • facilitation of intestinal absorption of calcium and phosphorus;
    • reabsorption of phosphorus in the kidney;
    • a direct effect on mineral metabolism of bone (deposition and reabsorption).
  • In conjunction with parathormone and calcitonin, it has a major role in homeostasis of calcium and phosphorus in the body's fluids and tissues.







Etiology

  • The causes of rickets are

  • 1. Deficient intake - less intake of Vitamin D containing foods:

    • non-adapted mixtures (to which vit D is not added);
    • milk feeding only for a long time (1 L of woman's milk contains 40-70 IU of vit D, cow's milk - 5-40 IU), late prescription of additional food (1 g of egg's yolk contains 140-390 IU of vit D);
    • vegetarian additional food predominantly (vegetables, porridges) without sufficient quantity of animal proteins and fats.


Etiology

  • 2. Inadequate direct exposure to ultraviolet rays in sunlight (296-310 nm; these rays do not pass through ordinary window glass).

  • 3. Disorders of absorption, such as celiac disease, steatorrhea, pancreatitis, cystic fibrosis or dysbacteriosis with diarrhea etc.





Etiology

  • Calcium and phosphorus homeostasis depends on the intestinal absorption of dietary calcium and phosphorus. Maximum calcium absorption occurs in humans when the ratio of calcium to phosphorus in the diet is about 2:1; increase in phosphate decreases absorption of calcium.

  • Acidity of intestinal contents increases absorption of calcium.

  • An increase in calcium absorption also occurs when lactose is the dietary sugar.



Etiology

  • Chelating agents such as the phytates of cereals may decrease calcium absorption.

  • Lignin provides the same effect upon vit D and its metabolites.

  • A great quantity of vegetables and cow milk nowadays contain plenty of phosphates (because of wide use of phosphate fertilizers), that inhibits absorption of Ca.



Etiology

  • 4. Perinatal factors. Prematurity predispose to rickets because the most intensive income of Ca and P from mother to fetus takes place during last months of pregnancy, so a baby born earlier than 30 weeks of gestation very often has osteopenia - more low content of mineral substances in bone.

  • At the same time they are need in greater quantity of Ca and P in food because of greater rate of postnatal growth comparatively with mature children.

  • Besides, prematurity, as well as placental insufficiency, is combined with much more low reserve in organism and more low level of vit D and its metabolites in cord blood.



Etiology

  • 5. Chronic liver disease - Defective absorption of vitamin D and calcium or inability to hydroxylate cholecalciferol.

  • 6. Kidney disease - Defective formation or increase destruction of 1,25 DHCC.

  • 7. Hereditary anomalies of metabolism of vit D, Ca and P.



Etiology

  • 8. Iatrogenic - Anticonvulsant therapy, as with Phenobarbital, may interfere in hepatic enzymes lead to increase breakdown of vitamin D. Glucocorticoids appear to be antagonistic to vitamin D in calcium transport.

  • 9. Ecological factors. Excess of strontium, zinc and other metals in soil, water, food leads to partial substitution of Ca by these substances.

  • 10. Pigmentation of skin decreases intensity of creation of cholecalciferol in skin.



Pathology

  • New bone formation is initiated by the osteoblast, which is responsible for matrix deposition and its subsequent mineralization.

  • Osteoblasts secrete collagen, and changes in polysaccharides, phospholipids, alkaline phosphatase, and pyrophosphatase follow until mineralization occurs in the presence of adequate calcium and phosphorus.

  • Resorption of bone occurs when osteoclasts secrete enzymes on the bone surface, dissolving and removing matrix and mineral.

  • Osteocytes covered by bone both resorb and redeposit bone.





Pathology

  • In rickets, defective growth of bone results from retardation or suppression of normal growth of epiphyseal cartilage and of normal calcification.

  • These changes depend on a deficiency in serum of calcium and phosphorus salts for mineralization.







Pathology

  • Cartilage cells fail to complete their normal cycle of proliferation and degeneration and instead continue to proliferate.

  • The result is a frayed, irregular epiphyseal line at the end of the shaft, failure of osseous and cartilaginous matrix to mineralize in the zone of preparatory calcification.

  • It causes deposition of newly formed uncalcified osteoid, which results in a wide, irregular, frayed zone of nonrigid tissue (the rachitic metaphysis or hyperplasia of osteoid tissue).

  • This zone becomes enlarged and bulges laterally, producing flaring of the ends of the bones and the rachitic rosary.



Pathology

  • Mineralization is also lacking in subperiosteal bone. It is called osteomalacia.

  • Pre-existing cortical bone is resorbed in a normal way but is replaced by osteoid tissues over the entire shaft, which fails to mineralize.

  • If this process continues, the shaft loses its rigidity, and the resultant softened and rarefied cortical bone is readily distorted by stress.

  • Deformities, fractures and bending result.





Chemical Pathology

  • In healthy infants the inorganic serum phosphorus concentration is 1.13-1.75 mmol/L, whereas in rachitic infants it is usually reduced.

  • The serum calcium level is usually normal, but under certain conditions it is reduced too, and tetany may develop.



Chemical Pathology

  • In the absence of vitamin D, less calcium is absorbed from the intestine.

  • With slightly lowered serum calcium, parathormone is secreted, leading to mobilization of calcium and phosphorus from the bone.

  • The serum calcium concentration is thus maintained, but secondary effects occur, including

    • the changes of rickets in bone,
    • the lowered serum phosphorus concentration (because parathormone decreases phosphorus reabsorption in the kidney), and
    • elevated serum phosphatase (due to increased osteoblastic activity).


Chemical Pathology

  • Vitamin D deficiency is also accompanied by

    • generalized aminoaciduria,
    • a decrease of citrate in bone and its increased miliary excretion,
    • decreased ability of the kidneys to make an acid urine, and, occasionally,
    • mellituria.
  • The parathyroid glands hypertrophy in rickets, and urinary cyclic adenosine monophosphate (AMP) level is increased.



Classification of Rickets



Classification of Rickets

  • In acute course of rickets symptoms of osteomalacia prevail.

  • In subacute - symptom hyperplasia of osteoid tissue.

  • Rickets may be classified as

    • calcium-deficient or
    • phosphate-deficient rickets.
  • The two types of rickets are distinguishable by their clinical manifestation.



Clinical Manifestations

  • Osseous changes of rickets can be recognized after several months of vitamin D deficiency.

  • In breast-fed infants whose mothers have osteomalacia, rickets may develop within 2 mo.

  • Florid rickets appears toward the end of the 1st and during the 2nd yr of life.

  • Later in childhood, manifest vitamin D deficient rickets is rare.



Clinical Manifestations

  • Early manifestation is syndrome of affection of nervous system. It revealed at initial period of disease as

    • irritability,
    • increased sweating, particularly around the head, while asleep,
    • interrupted sleep, and
    • quick persistent red dermographism.


Clinical Manifestations

  • Another manifestation at initial period is muscles hypotonia.

  • At the height of disease affection of nervous system revealed

    • flaccidity,
    • lag of motor development or rarely
    • nervous-psychical retardation (only in grave forms of disease).


Clinical Manifestations - Head

  • One of the early signs of rickets, craniotabes, is due to thinning of the outer table of the skull and detected by pressing firmly over the occipital or posterior parietal bones. A Ping-Pong-ball sensation will be felt.

  • The softness of the skull may result in flattening and, at times, permanent asymmetry of the head.

  • The anterior fontanel is larger than normal. Its closure may be delayed until after the 2nd yr of life (hypoplasia of osseous tissue).



Clinical Manifestations - Head

  • The central parts of the parietal and frontal bones are often thickened, forming prominences or bosses, which give the head a boxlike appearance (caput quadratum).

  • The head may be larger than normal and may remain so throughout life.

  • Eruption of the deciduos teeth may be delayed, and there may be defects of the enamel and extensive caries.



Clinical Manifestations - Thorax

  • Enlargement of the costochondral junctions may become prominent.The beading of the ribs (the "rachitic rosary") is not only palpable but also visible.

  • The sides of the thorax become flattened.



Clinical Manifestations - Thorax

  • The sternum with its adjacent cartilage appears to be projected forward, producing the so-called pigeon breast deformity.

  • Along the lower border of the chest develops a horizontal depression, Harrison groove, which corresponds with the costal insertions of the diaphragm.



















Clinical Manifestations – Spinal Column

  • Slight to moderate degrees of lateral curvature (scoliosis) are common, and

  • a kyphosis may appear in the dorsolumbar region of rachitic children when sitting.



Clinical Manifestations - Pelvis

  • In children with lordosis, there is frequently a concomitant deformity of the pelvis, which is also retarded in growth.

  • The pelvic entrance is narrowed by a forward projection of the promontory.

  • The exit, by a forward displacement of the caudal part of the sacrum and the coccyx.

  • In the female, these changes, if they become permanent, add to the hazards of childbirth and may necessitate cesarean section.



Clinical Manifestations – Extremities

  • As the rachitic process continues, the epiphyseal enlargement at the wrists and ankles becomes more noticeable.

  • The enlarged epiphyses can be seen or palpated. It is named "rachitic braсelets".

  • Besides the epiphyseal enlargement at finger's phalanges can be seen. It is named "thread of pearls".





Clinical Manifestations – Extremities

  • Bending of the softened shafts of the femur, tibia, and fibula results in

    • bowlegs (genu varum), or
    • knock-knees (genu valgum).
  • The femur and the tibia may also acquire an anterior convexity.

  • Greenstick fractures occur in the long bones; often there are no clinical symptoms.

  • Deformities of the spine, pelvis, and legs result in reduced stature, rachitic dwarfism.











Clinical Manifestations - Ligaments

  • Relaxation of ligaments helps to produce deformities and partly accounts for

    • knock-knees,
    • overextension of the knee joints,
    • weak ankles,
    • kyphosis, and
    • scoliosis.


Clinical Manifestations - Muscles

  • The muscles are poorly developed and lack tone.

  • As a result, children with moderately severe rickets are late in standing and walking.

  • Potbelly depends to a large extent on weakness of the abdominal muscles, weakness of the gastric and intestinal walls may contribute.









Clinical Manifestations

  • There are changes of internal organs:

    • cardio-vascular system,
    • respiratory tract,
    • digestive tract and so on,
    • increase of liver and spleen.
  • Anemia due to iron deficiency or accompanying infections often develops in severe rickets.



Roentgenography - Active Rickets

  • A roentgenogram of the wrist is best for early diagnosis because characteristic changes of the ulna and radius occur at an early stage.

  • The distal ends appear widened, concave (cupping), and frayed, in contrast to the normally sharply demarcated and slightly convex ends.



Roentgenography - Active Rickets

  • The distance from the distal ends of the ulna and radius to the metacarpal bones is increased because the large rachitic metaphysis, which is not calcified, does not appear on the roentgenogram.

  • The density of the shafts is decreased, but the trabeculae are unusually prominent.



Roentgenography - Initial healing

  • Initial healing is indicated by the appearance of the line of preparatory calcification.

  • This line is separated from the distal end of the shaft by a zone of decreased calcification, the zone of the osteoid tissue.

  • As healing progresses and the osteoid tissue becomes calcified, the shaft "grows" toward the line of preparatory calcification until it becomes united with it.











Complications

  • Respiratory infections such as bronchitis and bronchopneumonia are common in rachitic infants, and pulmonary atelectasis is frequently associated with severe deformities of the chest.



Prognosis

  • If sufficient amounts of vitamin D are administered, healing begins within a few days and progresses slowly until the normal bony structure is restored.

  • In advanced cases, there may be permanent osseous alterations in the form of

    • bowlegs,
    • knock-knees,
    • curvature of the upper arms,
    • deformities of the chest and spine,
    • rachitic pelvis and coxa vara, and
    • dwarfism.


Prognosis

  • Rickets in itself is not a fatal disease, but complications and intercurrent infections such as pneumonia, tuberculosis, and enteritis are more likely to cause death in rachitic children than in normal children.



Treatment

  • Common measures in rickets treatment are

    • rational diet,
    • walks outdoors,
    • massage and
    • gymnastics.
  • But oral administration of vitamin D is preferred.



Treatment

  • In initial stage of rickets 2000-3000 IU of vit D3 daily is enough.

  • In moderate rickets it's necessary to prescribe 3000-4000 IU of vit D3 daily.

  • In severe rickets - 4000-5000 IU of vit D3 daily.

  • Criterion of finishing the treatment is normalization of laboratory findings (usually 4-6 weeks).

  • After the course of treatment it's necessary to give preventive dose (500 IU D daily).



Treatment

  • Prescription of citrates is of great use.

  • If hypocalcemia is seen calcium must be given.

  • Anemia and other vitamin deficiency are treated accordingly (complex of vitamins A, E, B, and C with microelements).

  • If no healing occurs, the rickets is probably resistant to vitamin D.



Prevention

  • Prevention may be



Prevention

  • Antenatal prevention of rickets is carried out by obstetricians.

  • Specific prevention is not indicated in women older than 35 years, because of excessive Ca deposits in placenta and fetal hypoxia, atherosclerosis in women.



Prevention

  • Specific postnatal prevention begins from 1 mo with 500 IU of vit D daily all year round. It is the daily requirement of vit D.

  • In summer vit D is not given.

  • Rickets can be prevented by exposure to ultraviolet light, after course of which it is not necessary to give vit D 2 mo.



Prevention

  • Premature infants need the administration of 1000-2000 IU of vit D daily from 2 weeks.

  • Once in 2-3 weeks it is necessary to provide test of Sulkowitz.

  • If it is positive, vit D must be abolished.

  • Specific prevention isn't carried out in the children receiving formula feeding. It is fortified with vitamin D.



Prevention

  • Non-specific prevention signifies

    • rational feeding,
    • individual care,
    • sufficient stay outdoors,
    • gymnastics, and
    • massage.




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