Primary hypertrophic osteoarthropathy

Demographic

Rare disease of unknown cause that demonstrates an autosomal dominant genetic transmission, with marked variability of expression.

• Predominates and is more severe in Blacks.

Clinical

• Early insidious onset of
  • Enlargement of the hands and feet → a pawlike appearance
  • Clubbing of the distal ends of the fingers and toes
  • Convexity of the nails
  • Coarsening of the skin of the face and scalp (pachyderma)
  • Ptosis
  • Furrowing of the cutaneous tissue
  • Enlargement with disruption of the normal contour of the extremities
  • Vague pains in the bones and joints
• Progresses for 10-20 years before arresting spontaneously.
• Absence of significant joint pain

Imaging - Radiograph

• Widespread and symmetric osseous thickening due to periosteal proliferation, most pronounced in the tubular bones of the extremities
  • Spine involvement is unusual
• Effect diaphyses and metaphyses (like Secondary hypertrophic osteoarthropathy)
• Extends into the epiphyseal region, producing shaggy, ill-defined, bony excrescences.

Differential diagnosis

• Secondary hypertrophic osteoarthropathy
  • Later onset
  • Usually without family history
  • Significant joint pain (absence in pachydermoperiostosis)
• Thyroid acropachy
  • Fluffy, spiculated periosteal bone is encountered in the hands and feet but is rarely observed elsewhere.