What Is Reactive Arthritis?

Reactive arthritis (formerly called Reiter’s syndrome) is an inflammatory arthritis that develops in response to an infection elsewhere in the body—most commonly gastrointestinal infections (Salmonella, Shigella, Campylobacter, Yersinia) or sexually transmitted infections (Chlamydia trachomatis). The arthritis is not caused by the infection spreading to the joints but by an abnormal immune reaction triggered by the infection. Symptoms typically appear 1–6 weeks after the triggering infection, at a time when the infection itself may have already resolved or been treated.

The foot is disproportionately affected in reactive arthritis. The classic triad—joint inflammation, urethritis (urinary tract symptoms), and eye inflammation (conjunctivitis or uveitis)—is the historical description, but most patients do not present with all three components. The foot and heel manifestations are often the most prominent and disabling feature, and reactive arthritis should be considered whenever a patient develops sudden-onset inflammatory heel pain or foot joint swelling weeks after a gastrointestinal or genitourinary illness.

How Reactive Arthritis Affects the Foot

Enthesitis—inflammation at tendon and ligament insertion sites—is a hallmark of reactive arthritis and the seronegative spondyloarthropathies (the family of inflammatory conditions that includes reactive arthritis, ankylosing spondylitis, and psoriatic arthritis). In the foot, enthesitis produces severe heel pain at the insertion of the Achilles tendon (posterior heel) and the plantar fascia (plantar heel). For specialized treatment, see our heel pain treatment at Balance Foot & Ankle. This can closely mimic mechanical plantar fasciitis—the pain is at the same location—but inflammatory enthesitis is typically present at rest, worse in the morning with prolonged stiffness (lasting more than 30 minutes), and associated with warmth and swelling at the insertion sites rather than simply with activity.

Arthritis in reactive arthritis typically affects the joints of the lower extremities asymmetrically—the knee, ankle, and foot joints (particularly the metatarsophalangeal and toe joints) are most commonly involved. Dactylitis (“sausage toe”)—diffuse swelling of an entire toe from inflammation of all its joints and tendon sheaths simultaneously—is a characteristic finding that strongly suggests a spondyloarthropathy. Keratoderma blennorrhagica (thickened, warty plaques on the soles) and circinate balanitis are specific cutaneous manifestations that may be present.

Diagnosis and Treatment

Diagnosis is clinical—there is no definitive laboratory test for reactive arthritis. Workup typically includes: inflammatory markers (ESR, CRP—usually elevated), HLA-B27 typing (positive in approximately 50–80% of reactive arthritis patients—a genetic marker associated with spondyloarthropathies), testing for triggering organisms (Chlamydia PCR, stool cultures if recent GI illness), and joint aspiration to rule out septic arthritis (infection in the joint). Imaging (X-ray, MRI) assesses joint involvement and enthesitis severity.

NSAIDs (ibuprofen, naproxen, indomethacin) are the first-line treatment for reactive arthritis, providing significant symptom control in most patients. Corticosteroid injections at inflamed entheses (heel injection) provide targeted relief. For persistent arthritis beyond 3–6 months, disease-modifying antirheumatic drugs (sulfasalazine, methotrexate) are used. Biologic agents (TNF inhibitors) are reserved for severe refractory cases. Treating the triggering infection (if still active) is important but does not consistently accelerate joint recovery. Most cases of reactive arthritis resolve within 3–12 months; approximately 15–20% develop chronic recurrent arthritis.

Frequently Asked Questions

Medical References & Sources

• American College of Rheumatology — Reactive Arthritis
• PubMed Research — Reactive Arthritis Foot Manifestations
• PubMed Research — Enthesitis in Spondyloarthropathy

Dr. Tom Biernacki, DPM is a board-certified podiatric surgeon at Balance Foot & Ankle in Howell and Bloomfield Hills, Michigan. He evaluates inflammatory heel pain and foot arthritis, coordinates with rheumatology for spondyloarthropathy management, and provides local treatment including joint injections.

Dr. Tom Biernacki, DPM

Dr. Tom Biernacki, DPM is a double board-certified podiatrist and foot & ankle surgeon at Balance Foot & Ankle Specialists in Southeast Michigan. With over a decade of clinical experience, he specializes in heel pain, bunions, diabetic foot care, sports injuries, and minimally invasive surgery. Dr. Biernacki is a member of the APMA and ACFAS, and his patient education content on MichiganFootDoctors.com and YouTube has reached over one million views.