Table 14.20-4. Differential diagnosis of arthritis

Features

Disease

PsA

RA

OA

AS

Sex

M:F 1:1

M:F 1:3

OA of hands and feet more common in women

M:F 3:1

(but 1:1 in nrAxSpA)

Peripheral arthritis

Asymmetric

Symmetric

Varied

Involvement of distal interphalangeal joints

+

Heberden nodes

Sacroiliitis

Asymmetric

Symmetric

Stiffness

Morning stiffness of peripheral joints, cervical and lumbar spine

Morning stiffness

Stiffness associated with prolonged physical inactivity

Severe spinal stiffness

Enthesitis

+

+

Rheumatoid factor

+

HLA

B27, DR4

DR4

B27

Radiographic features

Erosions without osteopenia, “pencil-in-cup” deformity, juxta-articular new bone formation, large asymmetric syndesmophytes

Erosions, periarticular osteopenia

Osteophytes

Thin and symmetric syndesmophytes, vertebral osteopenia

AS, ankylosing spondylitis; F, female; M, male; nrAxSpA, nonradiographic axial spondyloarthritis; OA, osteoarthritis; PsA, psoriatic arthritis; RA, rheumatoid arthritis.