Question

Discussion

The answer is E: secondary hypertrophic osteoarthropathy. Hypertrophic osteoarthropathy is a syndrome of clubbing, periostitis, and synovitis.^1,2 It is characterized by new subperiosteal bone formation at the distal ends of long bones. More than 95 percent of cases are secondary (i.e., they are associated with an underlying systemic disease, most often a neoplasm or infection). Primary hypertrophic osteoarthropathy describes a case in which the cause is familial or idiopathic.^2–4

The most common cause of secondary hypertrophic osteoarthropathy is pulmonary neoplasm, typically a bronchogenic carcinoma (Figure 2). Less common causes include cystic fibrosis, bronchiectasis, cyanotic congenital heart disease, infective endocarditis, hepatoma, ulcerative colitis, and acquired immunodeficiency syndrome.⁴

Secondary hypertrophic osteoarthropathy can present with acute onset of redness, swelling, pain, and limited range of motion of the affected joints and bones. It is typically symmetric and associated with clubbing.¹

The results of laboratory tests such as rheumatoid factor and antinuclear antibodies are normal.¹ Periosteal new bone formation causes an elevated serum alkaline phosphatase level. If a joint effusion is present, the joint aspirate shows a noninflammatory fluid (cell count of less than 500 cells per μ L) with a lymphocytic and monocytic predominance.

Periostitis on long bone radiography is seen as new bone formation with periosteal elevation (Figure 3). A radioisotope bone scan shows diffusely increased uptake in the periosteum and is valuable in doubtful cases or when the radiographic images are normal.

Because hypertrophic osteoarthropathy is more often secondary than primary, an underlying cause must be sought. Furthermore, the only definitive therapy for secondary hypertrophic osteoarthropathy is treatment of the underlying condition. For example, secondary hypertrophic osteoarthropathy regresses in two to four weeks and may disappear by three to six months after surgical resection of the underlying causative tumor.⁵ Nonsteroidal anti-inflammatory drugs, steroids, or colchicine are treatment options if the hypertrophic osteoarthropathy is associated with pain.¹

Rheumatoid arthritis is a chronic, progressive disorder that symmetrically involves the synovial and articular surfaces of multiple joints. In rheumatoid arthritis, clubbing is absent and radiography shows periosteal sparing.

Primary hypertrophic osteoarthropathy, also known as pachydermoperiostosis or Touraine-Solente-Golé syndrome, is a rare autosomal dominant disorder occurring mainly in young males, characterized by hypertrophic osteoarthropathy with thickening and furrowing of facial skin (i.e., “leonine faces”).¹

Carpal tunnel syndrome is associated with insidious onset of hand paresthesias without any visible clinical swelling, erythema, or wrist deformity. Nerve conduction studies often help confirm the diagnosis.

Acute osteomyelitis is more common in children and immunosuppressed adults. Constitutional symptoms such as fever and malaise usually are present. Skin over the affected bone may be erythematous. Positive blood cultures with an elevated erythrocyte sedimentation rate aid in the diagnosis. Radiographic images can be normal early in the disease course, in which case a nuclear bone scan or magnetic resonance imaging can assist in the diagnosis.