Growing pains

Growing pains are a common, benign, and self-limited noninflammatory musculoskeletal pain syndrome that affects children. The cause remains unknown. Although growing pains have no standardized definition or diagnostic criteria, they are typically characterized by bilateral nonarticular pain in the lower extremities that occurs late in the day or during the night. Pain is absent during the daytime and when active. Growing pains are a clinical diagnosis. Individuals with atypical symptoms, abnormal examination findings, and/or features of systemic illness should receive a diagnostic evaluation to exclude other alternative diagnoses (e.g., overuse syndromes, anatomical abnormalities, infections, neoplasms). Management is supportive and consists of massage, heat therapy, and nonopioid oral analgesics. Most cases resolve spontaneously by adolescence.

• Unknown ^[1][2]
• No proven correlation with periods of rapid growth ^[1]

• Prevalence estimates vary. ^[2]
• Most commonly occurs between 3 and 12 years of age ^[1]

Epidemiological data refers to the US, unless otherwise specified.

Pain is the defining feature of growing pains and is typically characterized by the following: ^[1][3]

• Intensity: mild to severe
• Location ^[3]
  • Bilateral ^[1]
  • Most commonly affects the lower extremities (e.g., shins, calves, thighs, popliteal fossae)
  • Nonarticular
• Timing
  • Episodic (lasts minutes to hours) ^[4]
  • Occurs in the evening or nighttime and may:
    • Manifest after increased physical exertion
    • Awaken the child from sleep, but resolve by morning
  • Absent during the day or when active

Pain that limits activity should raise suspicion for differential diagnoses of growing pain. ^[1]

Approach ^[1][2]

• Perform a comprehensive history, review of systems, and physical examination to evaluate for:
  • Clinical features of growing pain
  • Red flag features
  • Differential diagnoses of leg pain in children
• Diagnose clinically if all of the following are met:
  • Consistent history
  • Normal physical examination
  • No red flag features
• If growing pains cannot be diagnosed from clinical findings, evaluate for alternative causes with, e.g.,:
  • Targeted studies
  • Specialty referral

Growing pains are a clinical diagnosis. ^[1][2]

Laboratory and/or imaging are used to evaluate for suspected alternative causes. ^[1][2]

Red flag features ^[1][2]

Any of the following clinical features suggests an alternative cause of growing pain.

• Constitutional symptoms
• Early morning pain or stiffness
• Pain during physical activity
• Unilateral or focal pain
• Persistent or worsening pain
• Abnormal examination findings (e.g., joint swelling, weakness, tenderness, gait changes, inability to bear weight)

Targeted studies ^[1][2]

Laboratory and imaging studies are normal in children with growing pains. Obtain targeted studies to exclude alternative causes based on clinical suspicion. ^[1][2]

• Laboratory studies
  • Systemic illness (e.g., inflammatory or infectious conditions)
    • CBC with differential
    • BMP
    • ESR or CRP
    • Suspected autoimmune arthropathy: ANA, anti-ds DNA, complement levels, urinalysis
  • Restless legs syndrome: CBC, iron studies
• Imaging: to evaluate for structural abnormalities, trauma, bone tumors, or infection
  • Initial: x-rays
  • Advanced imaging (e.g., MRI or bone scan): if x-rays are normal and there is a high level of clinical suspicion

• Overuse syndromes
  • Stress fracture
  • Apophysitis (e.g., Osgood-Schlatter disease, Sever disease)
• Anatomical abnormalities
  • Legg-Calvé-Perthes disease
  • Slipped capital femoral epiphysis
  • Developmental dysplasia of the hip
• Infection: osteomyelitis
• Neoplasms
  • Leukemia
  • Benign bone tumors, e.g., osteochondroma, chondroblastoma, osteoid osteoma
  • Malignant bone tumors, e.g.,: Ewing sarcoma, osteosarcoma
• Inflammatory and autoimmune conditions
  • Juvenile idiopathic inflammatory myopathy
  • Juvenile idiopathic arthritis
  • Systemic lupus erythematosus
• Neuromuscular
  • Restless legs syndrome
  • Progressive muscular dystrophies
• Hypermobility: Ehlers-Danlos syndrome

The differential diagnoses listed here are not exhaustive.

• Reassurance that growing pains are self-limited and benign ^[2]
• Symptomatic pain relief ^[1]
  • Over-the-counter pain medications: acetaminophen, ibuprofen (see “Nonopioid oral analgesia in children” for dosing)
  • Massage
  • Heat therapy

• Most cases resolve spontaneously by adolescence. ^[2]