المحاضرة الاولى.pdf

Rickets
Prepared by
Dr: Mojahed Al-shamag

1. Osteoid tissue (protein part) deficiency of it leads to KWO or osteoporosis.
2. Minerals parts (ca ,ph ,vitd3) deficiency leads to rickets or osteomalacia.
3. Collagen fibers (osteogensis imperfectia).
Cortex Of Bone

Definition
 Metabolic bone disease due to failure of mineralization of
osteoid tissue of the growing bones due to either:
- Defective intake or metabolism or function of vitamine D.
- Inappropriate calcium / phosphate ratio (usually due to
hypophosphatemia, rarely due to calcium deficiency)

VITAMIN D DISORDERS
• Vitamin D can be synthesized in skin epithelial cells and therefore technically is not a vitamin.
• Cutaneous synthesis: the most important source of vitamin D
7-dehydrochlesterol vitamin DR3R (3-cholecalciferol)
Ultraviolet B radiation
• The efficiency of this process is ↓ by melanin more sun exposure is necessary for vitamin D synthesis in
people with increased skin pigmentation.
• Covering the skin with clothing or applying sunscreen↓ vitamin D synthesis
• Fish liver oils have a high vitamin D content. Also, fatty fish and egg yolks.
• Breast milk has a low vitamin D content, approximately 12-60 IU/L.
• Supplemental vitamin D may be vitamin DR2R (which comes from plants or yeast) or vitamin DR3R; they are
biologically equivalent.
• Vitamin D is transported bound to vitamin D-binding protein to the liver
• 25-hydroxyvitamin D (25-D), the most abundant circulating form of vitamin D.
• measurement of 25-D is the standard method for patient's vitamin D status.
• Most 1,25-D circulates bound to vitamin D-binding protein.
• 1,25-D inhibits its own synthesis in the kidney and increases the synthesis of inactive metabolites.

Fee D T o y
♣ CalciFerol
♣ CalciDiol
♣ CalciTriol

Classification of rickets
Serum calcium
Type of rickets
Normal
Or
Low
Calcium deficiency with 2ry hyperparathyroidism
1. Nutritional vitamin D deficiency (Infantile rickets)
2. Secondary vitamin D deficiency due to:
o Malabsorption syndromes (Celiac rickets).
o Decreased liver 25-hydroxylase activity in chronic
liver disease
o Increased degradation e.g. with anti epileptic drugs.
3. Rickets with chronic renal failure (Renal osteodystrophy)
4. Vitamin D dependent rickets type I
5. Vitamin D dependent rickets type II
6. Calcium deficiency : nutritional , malabsorption or in
premature infant
Normal
Phosphate deficiency without 2ry hyperparathyroidism
1. Decreased phosphate intake
􀁸 Premature infants (rickets of prematurity)
2. Renal phosphate losses e.g.
􀁸 Familial hypophosphataemia.
􀁸 Fanconi syndromes
􀁸 Overproduction of phosphatonin e.g. Tumor-induced
rickets
Causes of rickets other than nutritional rickets are referred to as: Non vitamin D deficiency rickets (or Vitamin D refractory
or resistant) as they are not cured with the same dose or form of vitamin D that cures nutritional rickets

Vitamin D Deficiency Rickets
Predisposing factors
- Commoner in winter
- Commonest age 6 months  24 month.
- More in rapidly growing infant e.g. twins & preterm.
- Less in infants with arrested growth e.g. PCM & cretinism.

Etiology
A. Decreased vitamin D intake due to:
1. Lack of rich sources of vitamin D e.g. egg yolk, meat, fortified milks, fish
liver oil.
2. Use of rachitogenic diet with:
- Poor sources of vitamin D as fresh animal milk ,cereals and carbohydrates.
- Poor sources of calcium as cereals ,and excess leafy vegetables
- Inappropriate calcium /phosphate ratio as in fresh animal milk
B. Lack of access of ultra violet rays to the skin due to:
1. Lack of sun exposure
2. Poor sun exposure through glass windows, clouds & dust.
3. Excessive wrappings of the infants.
4. Poor penetration in dark skinned infants

Clinical picture
I. Early Rickets
1- Anorexia, irritability, & sweating of forehead
2- Craniotabes
- Skull bones yield under pressure 
Ping - pong or egg shell crackling sensation.
- Due to thinning of inner table of the skull
- Disappear by the end of 1st year.
- Detected by pressing over occipital or parietal
bone
3- Rachitic rosaries: palpable enlargement of costochondral junctions (excess
osteoid)

II. Advanced Rickets
1. Head • Large head
• Large anterior fontanel (delayed closure).
• Asymmetric skull; may be box shaped
• Frontal & parietal bones bossing due to
excess osteoid
• Depressed nasal bridge
• Delayed teething, dental caries
i. Skeletal Changes

2. Chest
• Rachitic rosaries
- Visible & Palpable.
- Rounded, Regular, Non tender
• Longitudinal sulcus  lateral to the rosaries
• Harrison sulcus transverse groove along the
costal insertion of the diaphragm
• Chest deformities:
* Pigeon chest sternum & adjacent cartilages
project forwards.
* Funnel chest depression of the sternum &
flaring out of the lower ribs.

3. Vertebral column : there may be
a. Kyphosis: in dorsolumbar region
- Smooth.
- Apparent on sitting, disappear by lifting.
- With compensatory lumbar lordosis
b. Scoliosis: lateral curvature of the spine
4. Extremities
a. Broadening of epiphysis of long
bones especially at wrist &
ankles.
b. Marfan sign: transverse groove
over the medial maleolus due to
unequal growth of the two
ossific centers.

c. Deformities: Due to weight bearing on the soft bones;
* Crawling infants:
- Bowing of forearm
- Anterolateral curvature of femurs
- Anteroposterior curvat1ure of legs
* Walking child:
- Bow legs(Genu varus)
- Knock knees (Genu valgum)
- Overextended knees(Genu recurvatum)

ii. Non Skeletal Manifestations
Manifestations:
1- Delayed motor milestones.
2- Abdominal distension (pot belly abdomen) ; with or without umbilical hernia
3- Ptosis of the liver & the spleen (also due to chest deformities).
4- Constipation due to intestinal hypotonia.
Etiology: - Hypotonia of skeletal muscles (due to hypophosphatemia)
- Laxity of ligaments
Complications
1- Respiratory infections & atelectasis due to:
a- Limited chest expansion.
b- Hypotonia of respiratory muscles weak cough reflex.
2- Gastroenteritis due to intestinal hypotonia stasis 2ry bacterial overgrowth.

3- Tetany : may occur in rickets with hypocalcaemia
4- Skeletal deformities: - Mild and early managed cases reversible.
- Advanced and neglected cases permanent.
5- Disproportionate short stature (Rachitic dwarfism)due to deformities of
spine, pelvis & limbs
6- Iron deficiency anemia is a common association ( Von-Jack anemia =
anemia ,rickets , lymphadenopathy and splenomegaly)

I. Biochemical
o Serum calcium is normal, but may be low (normal = 9 – 11 mg/dl).
o Serum inorganic phosphrus (Ph.) is low (normal value = 4.5 – 6.5 mg/dl).
o Serum Calcium × Phosphate product is low (less than 30).
o Serum alkaline phosphatase enzyme (Alk. Phos.):
- High
- The most sensitive indicator of rachitic activity; due to osteoblastic activity
- Return to normal after complete healing of rickets.
o Serum Parathyroid hormone (PTH) high.
o Serum 25 (OH) D3 low
o Serum 1.25 (OH)2 D3 low in severe vitamin D deficiency
Explanation: 1,25(OH)2 D3  calcium absorption serum calcium tend to be
low PTH calcium & ph. mobilization from bones + ph. loss
in urine normalized serum calcium + serum ph.

However hypocalcemia ( and may be tetany) may occur with:
1- Failure of 2ry hyperparathyroidism to occur.
2- In advanced cases with depletion of bone calcium.
3- Shock therapy  deposition of calcium Ph. in bone on the
expense of serum calcium which may fall below normal.

II. Radiologic: by X-ray at lower ends of long bones
especially wrist due to
easy access , rapid growth and soft tissue around is thin.
a. Active rickets
The lower ends show
• Broadening ; widening of the distal end of
the metaphysis
• Cupping or concavity ; metaphysis changes
from a convex or flat surface to a more
concave surface
• Metaphysis loses its sharp border ( Fraying )
• Wide joint space
Normal wrist Rachitic wrist

The shaft shows
• Rarefaction  bone density
• May be green stick fracture.
• May be deformities
b. Healing rickets
o Usually seen 2 weeks of vitamin D therapy
o The lower ends shows white concave continuous line at ZPC
o Less evident features of rickets
c. Healed rickets
o Usually seen 4 - 6 weeks of vitamin D therapy
o The lower ends show straight continuous line at ZPC.
o No features of active rickets.

Differential diagnosis from other causes of :
1. Non vitamin D deficiency rickets
2. Delayed motor milestones e.g. Inability to walk
3. Craniotabes which may occur in:
- Prematuredisappear by the 3rd month
- Hydrocephalusweakness affect all bones
- Osteogenesis imperfectweakness since birth
- Congenital syphilis.
4. Pott’s disease (T.B of spine): - Kyphosis is angular & persistent.
- X-ray and CT spine is diagnostic.
5. Rosary beads:
a. Scorbutic Rosaries: Due to deficient collagen subperiosteal hemorrhage
Criteria: - At costo chondral junctions.
- Angular, tender, irregular.
- With sternal depression.
- Associated with other clinical features of scurvy
c. False Rosaries in marasmus : Prominent normal costochondoral junctions

N.B. Atrophic rickets
- Rickets in non growing bones as in protein calorie malnutrition
- Absent osteoid overgrowth signs i.e. No bossing , wrist or ankle broadening ,rachitic
rosaries nor Marfan sign.
- Other signs of rickets are present e.g. wide fontanels, hypotonia,……

Treatment
1. Prevention
a. Vitamin D supplement usually as daily multivitamin
Dose: - For less than 1 year 400 IU/day mainly for Breast feeders
- For above 1 year 600 IU/day
b. Advice for:
- Exposure of pregnant mothers and infants to sunlight
- Diet with adequate calcium and phosphorus(formula, milk , dairy products)
- Vitamin D and calcium supplement for pregnant and lactating mothers

2. Curative
a. Vitamin D3:
* Oral : 2000 – 5000 IU/day for 4 - 6 weeks
* Stoss (Shock) therapy :
- 300.000- 600.000 IU IM or oral for 2-4 doses over 1day
- Indicated if compliance is uncertain
Either strategy should be followed by daily vitamin D intake maintenance
b. Advice parents for:
- Advice about Diet and sunlight as before
- Avoid weight bearing in infants during active rickets.
c. Treat complications:
* Tetany
* Deformities: osteotomy and reconstruction if severe and persistent.

After 4- 6 weeks of treatment: Look for criteria of improvement;
1. Radiologic : Appearance of zone of provisional calcification is the earliest finding.
2. Laboratory : Normalization of alkaline phosphatase indicates complete healing
3. Clinical: Improved muscle tone but skeletal manifestations may take a longer time
( Some skeletal signs may persist as large head , severe deformities, pigeon chest)
Decision: Reduce vitamin D dose to the normal daily requirement (to avoid toxicity)

Other Hypocalcemic Rickets
1. Rickets with malabsorption
• Clinical and lab features of malabsorption
+
• Clinical , lab and radiologic features of infantile rickets Treatment: Treat malabsorption
syndrome + 25 OH D3 or calcitriol (Better absorption) or Parenteral Vit D
The dose is adjusted based on monitoring of serum levels of 25-D
2. Rickets with chronic liver disease
• Clinical features of chronic liver diseasejaundice,
bleeding, edema
• Lab features of chronic liver disease Raised bilirubin ,
liver enzymes , prolonged PT , low albumin
+
• Clinical , lab and radiologic features of infantile rickets
Treatment : Treat chronic liver disease + 25 OH D3

3. Rickets with anti epileptic drugs
• Prolonged anti epileptic medicines ( phenytoin ,
phenobarbitone or carbamazepine )enzyme inducers 
inactivation of 25 (OH) D3
• Poor sun exposure or poor diet in neurologically disabled
+
Treatment: Oral calcium+ Sun exposure + 25 OH D3
Prevented by extra dose of vit D for all susceptible epileptics
4. Vitamin D dependent rickets type I
• Autosomal recessive defect in 1 hydroxylase enzyme
But
• Develop early in life
• Serum vitamin D: Normal 25 OH D3 / Low 1,25 (OH)2 D3
Treatment: Oral calcium + 1,25 (OH)2 D3 (R/Calcitriol)
Monitor urinary calcium excretion, with a target of <4 mg/kg/day

5. Vitamin D Dependent Rickets Type II
• Autosomal recessive end organ resistance to 1.25 (OH)2 D3
But
• Develop very early in life
• Serum vitamin D: Normal 25 OH D3 / High 1,25 (OH)2 D3
• Associated with short stature and alopecia totalis (severe)
Treatment: Oral calcium+ Calcitriol high dose may be of value
A trial period of 3-6 months with this regimen is initiated
Monitor urinary calcium excretion, with a target of <4 mg/kg/day

6. Renal Osteodystrophy (ROD) (Renal Glomerular Rickets)
Clinical picture
a. Features of chronic renal failure(anorexia ,anemia, growth failure, hypertension, …)
b. General features of rickets but:
- Deformities & fractures are very common due to combined effect of rickets &
secondary hyperparathyriodism.
- Tetany is rare as metabolic acidosis ionized Ca
- Bone pain and muscle weakness in older children.

Investigations
• Evidence of renal failure ( urea & creatinine),and anemia
• Urinary phosphate is low unlike other types of rickets
2- Radiologic
* General radiological features
* Evidence of secondary hyperparathyriodism:
- Subperiosteal erosions of bones
- May be bone cysts osteitis fibrosa cystica.

Management
A- Treatment of CRF  conservative treatment with or without dialysis.
B- Treatment of ROD in the following steps guided by target level of PTH as
decided by stage of renal failure:
1. Low phosphate diet (consult dietician).
2. Oral phosphate binders  Calcium carbonate (calcimate) or
Calcium acetate or
Non calcium based binders (sevelamer; Renagel)
3. Correct chronic metabolic acidosis by sodium bicarbonate tablets
4. Oral One alpha [1 (OH) D3] or calcitriol
5. Calcimemtic drugs e.g. Cinacalcet can suppress hyperparathyroidism without
inducing hypercalcemia
6. Partial parathyroidecomy for persistent hyperparathyroidism.

N.B. Congenital rickets
- Due to severe maternal vitamin D during pregnancy
- Presentation: a newborn with :
a- Classic rachitic changes
b- Hypocalcemic tetany
c- Intra uterine growth retardation
- Prevented by adequate prenatal sun exposure and vitamin D supply
N.B. Calcium deficiency rickets
Tend to present later than Vit D deficiency rickets ; namely after weaning
from breast feeding. May be associated with Vit D deficiency
Treated by supplemental calcium according to age

Hypophosphatemic Rickets
Renal Tubular Rickets
Rickets develop with renal tubular disorders due to either.
- Phosphaturia serum phosphate  serum Ca: Ph ratio become inappropriate for mineralization.
- Metabolic acidosis bone resorption.
Types of renal tubular rickets:
1- Familial hypophosphatemia
2- Fanconi syndromes:
a. Primary
b. Secondary
- Cystinosis (Lignac syndrome)
- Oculo-cerebro-renal (Lowe’s syndrome)
- Galactosemia.
- Out dated tetracycline , mercury poisoning

‫هللا‬ ‫رعاية‬ ‫في‬ ‫دمتم‬

المحاضرة الاولى.pdf

More Related Content

What's hot

Similar to المحاضرة الاولى.pdf

More from ssuser222ad9

Recently uploaded

المحاضرة الاولى.pdf