Reactive Arthritis Differential Diagnoses

Updated: Oct 05, 2022
  • Author: Carlos J Lozada, MD; Chief Editor: Herbert S Diamond, MD  more...
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Diagnostic Considerations

Gonorrhea and other types of infectious urethritis must be ruled out by means of microbiologic cultures of the urethral exudate. Gonococcal arthritis does not involve the spine. If reactive arthritis (ReA) occurs in a child as a result of a sexually transmitted disease, child protective service evaluation is mandatory.

Rheumatoid arthritis and psoriatic arthritis, as well as ankylosing spondylitis, must be differentiated from ReA. A disease flare of ankylosing spondylitis prompted by a minor diarrheal illness has been described as showing features of ReA. [84]

Septic arthritis and pyogenic arthritis also can mimic ReA. Septic arthritis must be ruled out if suspected before a diagnosis of ReA is made. Oligoarticular and asymmetrical involvement, together with the clinical course, may contribute to the diagnostic suspicion. Failure to treat septic arthritis appropriately in a timely manner could result in joint destruction.

Other seronegative arthritides can be present. The question of how to differentiate these conditions from ReA is academic because they share a common pathophysiologic pathway and similar treatment.

Rheumatic fever and serum sickness are characterized by a course that is more acute than that of ReA.

Cutaneous lesions of ReA can mimic the following, but the characteristic clinical picture must raise a suspicion of ReA: Norwegian scabies, mycosis fungoides, subcorneal pustulosis of Sneddon-Wilkinson, atopic dermatitis, acute exanthematic pustulosis, and other causes of erythroderma.

Syphilis may mimic ReA, especially secondary syphilis in its so-called malignant form with polymorphic vesicular pustules covered with thick crusts. [85]

Other conditions to be considered include the following:

  • Immunotherapy/immunization–related arthropathy

  • Synovitis, acne, pustulosis, hyperostosis, and osteomyelitis (SAPHO) syndrome

  • Pyogenic arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome

  • Systemic autoinflammatory disorders


Atopic Dermatitis

Balanitis Circumscripta Plasmacellularis

Balanitis Xerotica Obliterans


Behçet Disease

Campylobacter Infections




Contact Dermatitis, Irritant


Crohn Disease

Glaucoma, Drug-Induced

Glaucoma, Uveitic

Gout and Pseudogout

HLA-B27 Syndromes

Inflammatory Bowel Disease

Iritis and Uveitis

Juvenile Rheumatoid Arthritis

Kawasaki Disease

Lupus Erythematosus, Acute

Lyme Disease

Mycoplasma Infections


Psoriasis, Guttate

Psoriasis, Plaque

Psoriasis, Pustular

Red Eye Evaluation

Salmonella Infection



Synechia, Peripheral Anterior



Tick-Borne Diseases, Lyme

Uveitis, Anterior, Nongranulomatous

Ulcerative Colitis

Yersinia Enterocolitica Infection