Photo Quiz

Acute Onset of Polyarthralgia and Skin Plaques

MARIA LAPLANTE, MD, and RICHARD USATINE, MD, University of Texas Health Science Center, San Antonio, Texas

Am Fam Physician. 2015 May 15;91(10):723-724.

A 52-year-old Hispanic man presented with two weeks of severe pain and swelling in his knees and wrists that affected his ability to walk. He had a rash on his thighs, knees, hands, and lower back. He did not have fever, dysuria, or eye pain. He had no significant medical history.

His vital signs were normal. He had red-purple, round plaques with scale on his bilateral lower extremities, dorsum of his hands, over the sacral region of his lower back, and in the inguinal region (Figure 1). His palms were normal, but the soles of his feet had a thick, yellow, keratotic scale. There was no fingernail pitting. There was prominent joint swelling and effusion in his wrists and knees (Figure 2), with mild tenderness and limited range of motion. There was diffuse swelling of the right thumb with nail dystrophy.

Laboratory studies revealed an elevated C-reactive protein level of 222 mg per L (2,114.33 nmol per L) and erythrocyte sedimentation rate of 113 mm per hour. Serology tests were positive for Chlamydia trachomatis immunoglobulin M and G.

Figure 1.

Figure 2.

Question

Based on the patient's history, physical examination, and laboratory findings, which one of the following is the most likely diagnosis?

A. Psoriatic arthritis.

B. Reactive arthritis.

C. Rheumatoid arthritis.

D. Systemic lupus erythematosus.

Discussion

The correct answer is B: reactive arthritis. Reactive arthritis is a syndrome that classically involves polyarthritis, urethritis, uveitis, and psoriasiform skin findings in response to a genitourinary or gastrointestinal infection. The acute onset of two of these features, along with testing positive for chlamydia and human leukocyte antigen B27 (HLA-B27) and high inflammatory markers, established the diagnosis in this patient. Only about one-third of patients with the condition present with the classic triad.1 Symptoms typically develop within four weeks of the infection. The most commonly associated pathogens are Chlamydia trachomatis, Shigella, Campylobacter, Salmonella, Yersinia, and Clostridium difficile.1 The mechanism by which these organisms trigger the arthritis and associated symptoms is not well understood.1 The disease is usually self-limited, with most patients symptom-free within 12 months.1

Patients with reactive arthritis may present with a wide variety of symptoms. The skin findings in this patient included plaques of scale, thick keratotic scaling of the plantar feet (keratoderma blennorrhagicum), and nail dystrophy. The arthritis typically presents as an asymmetric polyarthritis, most commonly affecting the knees and ankles. Back and heel pain are also common.1 Conjunctivitis is the most common ophthalmologic finding, affecting approximately 30% to 60% of patients. Uveitis occurs in 12% to 37% of patients and may result in permanent vision loss if untreated.2 The psoriasiform skin findings occur in 5% of patients and present as red plaques with scale on the extensor surfaces of the lower extremities and dorsum of hands and fingers.2

The diagnosis of reactive arthritis is based on history and clinical examination findings. Testing is positive for HLA-B27 in about 70% to 80% of patients with reactive arthritis, and may indicate more serious disease.1 Elevated erythrocyte sedimentation rate and C-reactive protein measurements are common. The patient should be tested for C. trachomatis, and stool cultures should be evaluated for gastrointestinal infection. Joint aspiration can show leukocytes. Radiographs of the affected joints may show soft tissue swelling associated with joint effusions.1

Psoriatic arthritis is a chronic inflammatory, immune-mediated disease that can have clinical findings similar to those of reactive arthritis, especially the skin manifestations. The condition commonly affects the hands, feet, knees, and/or spine, and patients often have a family history of psoriasis. Chlamydia and HLA-B27 are not commonly associated with psoriatic arthritis. Inflammatory markers may be elevated but typically not as high as with a reactive arthritis.

Rheumatoid arthritis is a chronic inflammatory disease that presents with polyarthralgias and polyarthritis, typically affecting the proximal interphalangeal and metacarpophalangeal joints of the hands. Radiographs often show joint deformities and erosive changes. Subcutaneous (rheumatoid) nodules are the typical skin finding.3 Serologic testing is usually positive for rheumatoid factor.

Systemic lupus erythematosus is a chronic inflammatory disease with polyarthralgias of the hands, wrists, and knees. Skin manifestations are usually in photodistributed areas, such as a malar rash across the cheeks, sparing the nasolabial folds.3 Systemic lupus erythematosus is associated with positive antinuclear antibody test results.

Summary Table

Condition Characteristics Test results

Psoriatic arthritis

Chronic inflammatory polyarthritis affecting the hands, feet, knees, and/or spine; personal or family history of psoriasis is common

No specific serologic testing; erosions with "pencil in cup" deformity on radiography; may be positive for HLA-B27, but this is less common

Reactive arthritis

Acute polyarthritis, urethritis, uveitis, psoriasiform skin lesions; develops within four weeks of infection

Positive for genitourinary or gastrointestinal infection; positive for HLA-B27

Rheumatoid arthritis

Chronic inflammatory polyarthritis; typically affects the proximal interphalangeal and metacarpophalangeal joints of the hands; associated with joint deformities and erosive changes; subcutaneous (rheumatoid) nodules

Positive for rheumatoid factor; deformities and erosive changes on radiography

Systemic lupus erythematosus

Chronic polyarthritis of hands, wrists, and knees; malar rash across the cheeks, sparing the nasolabial folds

Positive for antinuclear antibody

To see the full article, log in or purchase access.

Address correspondence to Maria LaPlante, MD, at laplante@uthscsa.edu. Reprints are not available from the authors.

Author disclosure: No relevant financial affiliations.

REFERENCES

1. Wu IB, Schwartz RA. Reiter's syndrome: the classic triad and more. J Am Acad Dermatol. 2008;59(1):113–121.

2. Bolognia J, Jorizzo JL, Schaffer JV, eds. Dermatology. 3rd ed. Edinburgh, Scotland: Elsevier Saunders; 2012.

3. Usatine R, ed. The Color Atlas of Family Medicine. 2nd ed. New York, NY: McGraw-Hill; 2013.

This series is coordinated by John E. Delzell, Jr., MD, MSPH, Assistant Medical Editor.

A collection of Photo Quiz published in AFP is available at https://www.aafp.org/afp/photoquiz.

Previously published Photo Quizzes are now featured in a mobile app. Get more information at https://www.aafp.org/afp/apps.

The editors of AFP welcome submissions for Photo Quiz. Guidelines for preparing and submitting a Photo Quiz manuscript can be found in the Authors' Guide at https://www.aafp.org/afp/photoquizinfo. To be considered for publication, submissions must meet these guidelines. E-mail submissions to afpphoto@aafp.org.

Copyright © 2015 by the American Academy of Family Physicians.
This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP. Contact afpserv@aafp.org for copyright questions and/or permission requests.

MOST RECENT ISSUE

Dec 2021

Access the latest issue of American Family Physician

Read the Issue


Email Alerts

Don't miss a single issue. Sign up for the free AFP email table of contents.

Sign Up Now