Image Quizzes

Elbow tenderness and swollen joints

Reviewed by Herbert S. Diamond, MD


A 45-year-old man presents with complaints of intermittent joint aches to the point that he can no longer golf and has trouble with his handwriting. He has a 6-year history of scalp psoriasis that he has controlled with a salicylic acid shampoo. On physical examination, he has tenderness over both elbows and in his metacarpophalangeal and proximal interphalangeal joints on both hands. Swollen joints are noted in the proximal and distal joints of the right hand. His fingernails show uniform pitting. Neurologic examination shows no sensory deficits or hyperesthesia. Motor examination is unremarkable, as are chest and abdominal findings. Blood pressure is 128/80 mm Hg. Radiographic findings showed periarticular soft-tissue swelling of the distal interphalangeal joints of the right second and fourth fingers and left thumb, although no significant bony abnormalities were observed. There is asymmetric narrowing of the joint space in the interphalangeal joints. Laboratory findings reveal an erythrocyte sedimentation rate of 35 mm/h, negative for rheumatoid factor, negative for antinuclear antibody, and C-reactive protein level of 9 mg/dL.

What is the likely diagnosis?

Psoriatic arthritis



Rheumatoid arthritis


The diagnosis for this case is psoriatic arthritis (PsA). The 2018 American College of Rheumatology/National Psoriasis Foundation guidelines offer current treatment recommendations for this condition. For patients with active PsA who are treatment-naive, treatment recommendations are:

  • Tumor necrosis factor (TNF) inhibitors are preferred over oral small molecules (OSMs), interleukin (IL)–17 inhibitors, or IL-12/23 inhibitors
  • OSMs are recommended over IL-17 inhibitors or IL-12/23 inhibitors
  • Methotrexate is recommended over nonsteroidal anti-inflammatory drugs
  • IL-17 inhibitors are recommended over IL-12/23 inhibitors

Treatment recommendations for patients with active PsA despite the use of OSMs are:

  • Switching to a TNF inhibitor over another OSM, IL-17 or IL-12/23 inhibitors, abatacept, or tofacitinib
  • Switching to an IL-17 inhibitor over another OSM, IL-12/23 inhibitor, abatacept, or tofacitinib
  • Switching to an IL-12/23 inhibitor over another OSM, abatacept, or tofacitinib.

International groups, such as the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) and the European League Against Rheumatism (EULAR), have published treatment recommendations as well. These address both PsA and, to a lesser extent, psoriasis. The GRAPPA recommendations consider six domains of involvement (peripheral arthritis, axial disease, enthesitis, dactylitis, skin psoriasis, and nail psoriasis) and use a grid approach to account for various levels of disease activity and severity. The EULAR recommendations use an algorithmic approach that focuses mainly on musculoskeletal manifestations, specifically peripheral arthritis; manifestations, such as dactylitis, enthesitis, and skin and nail involvement, are considered separately.

Psoriasis precedes the onset of PsA in 60%-80% of patients (sometimes by up to 20 years but usually by less than 10 years); but in as many as 15%-20% of patients, arthritis appears before psoriasis. On occasion, arthritis and psoriasis appear simultaneously.

Patients with PsA are typically seronegative for rheumatoid factor and antinuclear antibody; antinuclear antibody titers in persons with PsA do not differ from those of age- and sex-matched controls. C-reactive protein may be elevated but is often normal. Lack of C-reactive protein elevation, however, does not mean that systemic inflammation is absent but rather indicates that a different type of systemic inflammation may be at play for those patients.

Herbert S. Diamond, MD, Professor of Medicine (retired), Temple University School of Medicine, University of Pittsburgh; Chairman, Department of Medicine Emeritus, Western Pennsylvania Hospital, Pittsburgh, PA.

Herbert S. Diamond, MD, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

More Challenges For You

Stiffness in the distal joints
Psoriatic Arthritis Comorbidities
Psoriatic Arthritis Treatment Guidelines
Fatigue and overall stiffness