Below is a concise but comprehensive paediatric reference for Rickets and Scurvy, structured for quick study and revision.
Rickets in Paediatrics
Definition
Rickets is a disorder of growing bone in children caused by defective mineralization of the growth plate (physis) due to deficiency or abnormal metabolism of vitamin D, calcium, or phosphate, leading to soft and deformed bones.
Occurs only in children with open epiphyseal plates.
Pathophysiology
Normal bone mineralization requires:
- Vitamin D
- Calcium
- Phosphate
Steps:
- Vitamin D → converted in liver to 25-hydroxyvitamin D
- Kidney converts it to 1,25-dihydroxyvitamin D (active form)
- Active vitamin D increases:
* intestinal calcium absorption
* phosphate absorption
- Deficiency → hypocalcemia
- Hypocalcemia → secondary hyperparathyroidism
- PTH increases phosphate excretion → hypophosphatemia
- Poor mineralization of osteoid → rickets
Causes
Nutritional
Most common worldwide.
Causes:
- Vitamin D deficiency
- Low calcium intake
- Prolonged exclusive breastfeeding without supplementation
- Limited sunlight exposure
- Malnutrition
Malabsorption
- Celiac disease
- Chronic diarrhea
- Cystic fibrosis
- Biliary disorders
Renal Causes
- Chronic kidney disease
- Renal tubular acidosis
- Renal phosphate wasting
Genetic Causes
- Vitamin D–dependent rickets type I
- Vitamin D–dependent rickets type II
- X-linked hypophosphatemic rickets
Drug Induced
- Antiepileptic drugs (phenytoin, phenobarbital)
- Rifampicin
Risk Factors
- Prematurity
- Dark skin pigmentation
- Exclusive breastfeeding without vitamin D
- Lack of sunlight
- Malnutrition
- Chronic illness
Clinical Features
Early Symptoms
- Irritability
- Delayed growth
- Delayed motor milestones
- Bone pain
- Muscle weakness
Skeletal Signs
Skull
- Craniotabes
- Frontal bossing
- Delayed closure of fontanelle
Chest
- Rachitic rosary
- Harrison groove
- Pigeon chest
Limbs
- Bow legs (genu varum)
- Knock knees (genu valgum)
- Wrist widening
- Ankle widening
Spine
- Kyphosis
- Scoliosis
Other Features
- Delayed dentition
- Dental enamel defects
- Hypocalcemic seizures
- Tetany
Investigations
Blood Tests
Typical findings:
Calcium
- Low or normal
Phosphate
- Low
Alkaline phosphatase
- Markedly increased
Parathyroid hormone
- Increased
25-OH vitamin D
- Low
Radiology
X-ray features:
- Metaphyseal cupping
- Metaphyseal fraying
- Metaphyseal widening
- Poor mineralization
Common sites:
- Wrist
- Knee
Differential Diagnosis
- Osteogenesis imperfecta
- Hypophosphatasia
- Skeletal dysplasia
- Blount disease
- Renal osteodystrophy
Management
Goals
- Correct vitamin deficiency
- Restore calcium and phosphate balance
- Prevent bone deformity
Non-Pharmacological Management
- Adequate sunlight exposure
- Balanced nutrition
- Calcium-rich diet
- Early treatment
Pharmacologic Treatment
Vitamin D Therapy
Drug: Cholecalciferol
Mechanism
Increases intestinal absorption of calcium and phosphate, promoting bone mineralization.
Indication
Treatment of nutritional rickets.
Usual Dosing
Infants
2000 IU/day for 6 weeks
Children
3000–6000 IU/day for 6 weeks
Alternative: Stoss therapy
- Single dose 300,000–600,000 IU
Pharmacokinetics
Absorbed in intestine → stored in liver → activated in kidney.
Common Adverse Effects
- Hypercalcemia
- Nausea
- Vomiting
Serious Effects
- Kidney stones
- Renal failure (rare)
Contraindications
- Hypercalcemia
- Vitamin D toxicity
Drug Interactions
- Antiepileptics reduce vitamin D levels
- Steroids reduce vitamin D effect
Monitoring
- Serum calcium
- ALP
- Vitamin D levels
Counseling
- Give with food
- Ensure adequate sunlight exposure
- Avoid overdose
Calcium Supplementation
Drug: Calcium carbonate
Indication
Used with vitamin D in rickets.
Dose
30–75 mg/kg/day elemental calcium.
Adverse Effects
- Constipation
- Hypercalcemia
Complications
- Permanent bone deformities
- Growth retardation
- Pathological fractures
- Hypocalcemic seizures
Prevention
- Vitamin D supplementation
Recommended dose:
Infants
400 IU/day
Children
600 IU/day
- Adequate sunlight exposure
- Proper nutrition
Prognosis
Good with early treatment.
Bone deformities may require orthopedic surgery if severe.
Scurvy in Paediatrics
Definition
Scurvy is a disease caused by vitamin C deficiency, leading to defective collagen synthesis, resulting in bleeding, bone abnormalities, and poor wound healing.
Pathophysiology
Vitamin C is essential for:
- Collagen synthesis
- Capillary integrity
- Iron absorption
- Wound healing
Deficiency → defective collagen → fragile blood vessels and bone abnormalities.
Causes
Nutritional Deficiency
Most common cause.
Risk factors:
- Poor diet lacking fruits and vegetables
- Exclusive milk feeding
- Autism with restricted diet
- Severe malnutrition
Clinical Features
General Symptoms
- Irritability
- Fatigue
- Poor appetite
Musculoskeletal Signs
- Bone pain
- Refusal to walk
- Pseudoparalysis
- Swollen joints
Skin Signs
- Petechiae
- Purpura
- Easy bruising
Gum Changes
- Bleeding gums
- Swollen gums
- Tooth loss
Hair Changes
- Corkscrew hairs
Investigations
Blood tests:
- Low vitamin C level
- Anemia (often present)
X-ray findings:
- White line of Frankel
- Pelkan spur
- Wimberger ring
- Osteopenia
Differential Diagnosis
- Leukemia
- Osteomyelitis
- Septic arthritis
- Child abuse
- Rickets
Management
Non-Pharmacologic
- Vitamin C rich diet
Foods rich in vitamin C:
- Citrus fruits
- Tomatoes
- Guava
- Green vegetables
Pharmacologic Treatment
Drug: Ascorbic acid
Mechanism
Acts as cofactor in collagen synthesis and antioxidant.
Indication
Treatment and prevention of scurvy.
Dosing
Children
100–300 mg/day for 1 month
Maintenance
50–100 mg/day
Pharmacokinetics
Water-soluble vitamin; excess excreted in urine.
Common Adverse Effects
- Nausea
- Abdominal cramps
Serious Effects
- Kidney stones (high doses)
Contraindications
- Hypersensitivity
Monitoring
- Clinical improvement
- Hemoglobin level
Counseling
- Encourage diet rich in fruits
- Avoid prolonged exclusive milk diet
Complications
- Severe anemia
- Hemorrhage
- Growth delay
Prognosis
Excellent.
Symptoms usually improve within days of treatment.
If you want, I can also provide high-yield exam tables such as:
- Rickets vs Scurvy comparison
- Radiological signs comparison
- NEET PG / USMLE exam pearls.
