Osteomalacia (rickets)

Osteomalacia (rickets)

OVERVIEW:

Osteomalacia (referred to as rickets in children) is defined as an excess organic bone matrix secondary to defective or inadequate bone mineralization

System(s) affected: Musculoskeletal
Genetics: N/A
Incidence/Prevalence in USA: N/A
Predominant age: All ages. In adults, osteomalacia is usually a disease of the older population (50-80).
Predominant sex: Female > Male (slightly)

SIGNS AND SYMPTOMS:

• Bone pain, tenderness, muscle weakness
• Bone pain is dull and tends to be poorly localized, usually affecting the ribs and upper thighs
• Muscle weakness is usually proximal
• Other symptoms of malnutrition or an underlying problem such as chronic renal disease may also be clinically evident
• Weight loss
• Anorexia
• Tetany
• In young children - restlessness, poor sleep patterns, craniotabes, costochondral beading, bowlegs, kyphoscoliosis

CAUSES:

• Can be caused by a wide variety of pathogenic processes, including, but not limited to, vitamin D deficiency (reduced exposure to sunlight, poor nutrition, malabsorption syndromes)
• Defective metabolism of parent vitamin D to active metabolites (drug-induced, i.e., anticonvulsants - phenytoin (Dilantin), chronic renal failure), hypophosphatemia (renal tubular acidosis, hypophosphatemic syndrome), miscellaneous (long-term hemodialysis, malnutrition, vitamin D-dependent rickets)

RISK FACTORS:

• Poverty
• Inadequate nutrition and sunlight exposure

DIAGNOSIS

DIFFERENTIAL DIAGNOSIS:

• Osteoporosis
• Metastatic bone disease
• Primary bone malignancies (lymphoma, myeloma)

LABORATORY:

• Alkaline phosphatase - increased
• Serum calcium is low or normal (never high)
• Hypophosphatemia
• Aminoaciduria
• Acidosis
• Glucosuria
• Hypouricemia

Drugs that may alter lab results: N/A
Disorders that may alter lab results: N/A

PATHOLOGICAL FINDINGS:

• Defective calcification of growing bone
• Hypertrophy of epiphyseal cartilages

SPECIAL TESTS:

N/A

IMAGING:

Radiographic changes are non-specific. Earliest manifestations are thinning of cortical bone. In long-term osteomalacia: bone softening (protrusio acetabuli), looser lines, stress fractures, and pathologic fractures.

DIAGNOSTIC PROCEDURES:

Bone biopsy and subsequent histopathologic evaluation deliver the most accurate diagnosis of osteomalacia. The biopsy is usually taken from the iliac crest, and both calcified, and non-calcified studies, as well as special stains (including von Kossa's stain) are helpful.

TREATMENT

APPROPRIATE HEALTH CARE:

Can be managed on an outpatient basis, except for complicating emergencies/fractures

GENERAL MEASURES:

• Treatment of osteomalacia depends upon the cause, i.e., gastrointestinal, renal, or nutritional.
• For nutritional osteomalacia, calcium and vitamin D have been shown to correct the disease process
• Treatment can be monitored by observing simple bone biochemistry
• Treatment results depend on identifying and correcting the cause

SURGICAL MEASURES:

N/A

ACTIVITY:

Full activity is encouraged, including a neuroconditioning program

DIET:

• Ensure adequate vitamin D intake
• Provide instructions for a high calcium diet and information on calcium supplements, if appropriate

PATIENT EDUCATION:

Educate family and patient on nutrition

MEDICATIONS

DRUG(S) OF CHOICE:

For adults and uncomplicated rickets: vitamin D (ergocalciferol) 2000-4800 IU once a day for one month. Then reduce dose gradually.

Contraindications: N/A
Precautions: N/A
Significant possible interactions: N/A

ALTERNATIVE DRUGS:

• IV calcium salts if tetany complicates. Single IM dose of 100,000 IU in adolescents each Fall.
• Alfacalcidol
• Calcitriol

FOLLOW UP

PATIENT MONITORING:

Office visits every 6 months

PREVENTION/AVOIDANCE:

• Adequate dietary intake of vitamin D
• Adequate sunlight exposure
• Fortified cow's milk

POSSIBLE COMPLICATIONS:

• Fractures
• Osteomyelitis
• Renal failure
• Renal tubular acidosis
• Seizures
• Growth deformity; bowing long bones in children

EXPECTED COURSE AND PROGNOSIS:

Variable

MISCELLANEOUS

ASSOCIATED CONDITIONS:

• Chronic renal disease
• Epilepsy
• Malnutrition
• Previous gastric surgery
• Pregnancy-nutritional factors

AGE-RELATED FACTORS:

Pediatric: N/A
Geriatric: Studies have suggested that vitamin D deficiency osteomalacia is a relatively common condition in the acutely ill elderly population, with an estimated prevalence of about 3-5%; however, it often goes undiagnosed
Others: N/A

PREGNANCY:

N/A

SYNONYMS:

Rickets

ICD-9-CM:

268.2 Osteomalacia, unspecified

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SEE ALSO (Enter the keywords below into our search box or click on the link):

Pruritus ani
Pruritus vulvae
Dermatitis, contact
Dermatitis, stasis

Medical Diagnosis » O » Osteomalacia (rickets)