How Is Rickets Diagnosed?

Rickets is a childhood bone disorder caused by inadequate mineralization of the growing skeleton. Most commonly linked to vitamin D deficiency, rickets leads to soft, weak bones that may bend or break easily. Early detection and treatment can help children grow strong and healthy. Here’s a clear guide on how rickets is diagnosed.

1. Recognizing Warning Signs

Diagnosis begins with identifying symptoms or risk factors. Parents and caregivers should watch for:

• Slowed growth or shorter-than-average height
• Bone pain or tenderness, especially in the legs, ribs, or arms
• Delayed motor milestones (sitting, crawling, walking)
• Muscle weakness or low muscle tone
• Visible bone deformities, such as bowed legs, knock knees, or a curved spine
• Dental issues: delayed tooth eruption, enamel defects
• Frequent fractures with minimal trauma

Children with limited sun exposure, darker skin, or diets extremely low in vitamin D and calcium are at higher risk. Premature infants, exclusively breast-fed babies without supplementation, and those with certain medical conditions (e.g., malabsorption syndromes) should raise suspicion.

2. Detailed Medical History

A thorough history helps pinpoint underlying causes:

• Dietary intake
  • Breast-fed infants without vitamin D drops
  • Diets low in fortified milk, fish, eggs or dairy
• Sun exposure
  • Time spent outdoors
  • Sunscreen use, clothing habits
• Family history
  • Genetic forms of rickets (e.g., vitamin D–resistant rickets)
• Medical conditions
  • Kidney or liver disease
  • Gastrointestinal disorders that impair fat absorption
• Medications
  • Drugs that affect vitamin D metabolism (e.g., anticonvulsants, glucocorticoids)

3. Physical Examination

A pediatrician or specialist looks for classic signs:

• Growth assessment
  • Height, weight and head circumference compared to age norms
• Bone deformities
  • Bowed legs (genu varum) or knock knees (genu valgum)
  • Rachitic rosary: bumps along the rib cage
  • Wrist widening or thickening of the ankle
• Muscle tone and strength
  • Generalized hypotonia (low muscle tone)
  • Difficulty standing or climbing stairs
• Dental exam
  • Enamel defects, delayed tooth eruption

4. Laboratory Tests

Lab studies confirm biochemical changes typical of rickets. Key tests include:

• Serum calcium
• Serum phosphate
• Alkaline phosphatase (ALP)
• Parathyroid hormone (PTH)
• 25-hydroxyvitamin D (25[OH]D)

Typical findings in nutritional vitamin D–deficiency rickets:

• Low calcium
• Low phosphate
• Elevated ALP
• Elevated PTH (secondary hyperparathyroidism)
• Low 25[OH]D

Genetic or renal causes may show different patterns. For example, in vitamin D–resistant rickets, phosphate loss through the kidneys leads to low serum phosphate despite normal vitamin D levels.

5. Imaging Studies

X-rays help visualize changes in growing bones. Common radiographic sites:

• Wrists
• Knees
• Ankle regions

Characteristic findings:

• Widened, cupped, and frayed metaphyses (growing ends of long bones)
• Generalized bone demineralization
• Bowing of the femur or tibia

In mild cases, X-rays may be normal. Repeat imaging and clinical correlation are essential.

6. Additional Tests

When initial labs and X-rays are inconclusive or suggest non-nutritional causes:

• Renal function tests (blood urea nitrogen, creatinine)
• Liver function tests
• 1,25-dihydroxyvitamin D levels (active form)
• Urinary calcium and phosphate excretion
• Genetic testing for hereditary forms of rickets

These help differentiate nutritional rickets from renal, genetic or other metabolic bone diseases.

7. Differential Diagnosis

Rickets shares features with several conditions. Your doctor may consider:

• Osteomalacia (in adults)
• Skeletal dysplasias (e.g., achondroplasia)
• Hypophosphatasia
• Metaphyseal dysplasia
• Bone infections or tumors

Accurate diagnosis ensures the right treatment plan.

8. Next Steps and Treatment Planning

Once rickets is confirmed, treatment typically involves:

• Vitamin D supplementation (dosing based on severity)
• Dietary adjustment to increase calcium and phosphate
• Safe sun exposure recommendations
• Monitoring growth, labs and X-rays periodically
• Orthopedic evaluation for severe bone deformities

Early intervention promotes normal bone development and reduces long-term complications.

9. Immediate Actions You Can Take

If you suspect your child may have rickets, consider a free, online symptom check, using the doctor approved Ubie Symptom Checker to help guide your next steps. This tool is not a substitute for medical advice but can help you decide how urgently to seek care.

10. When to Speak to a Doctor

Any of the following warrant prompt medical attention:

• Severe bone pain or inability to bear weight
• Noticeable bone deformities worsening over time
• Signs of serious vitamin D deficiency (e.g., seizures from low calcium)
• Growth delays or developmental regression

Always speak to a doctor about symptoms that could be life-threatening or indicate serious health issues. Early diagnosis and treatment of rickets are key to helping children achieve healthy growth and development.

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Note: This information is educational and should not replace professional medical advice. Always follow your healthcare provider’s guidance regarding diagnosis and treatment.