= REITER SYNDROME

[Hans Conrad Julius Reiter (1881–1969), German bacteriologist and hygienist in institute of hygiene in Königsberg and Berlin-Dahlem convicted of war crimes at the Nürnberg trials for his medical experiments in the concentration camp at Buchenwald]

= noninfectious, asymmetric inflammatory oligoarthropathy characterized by the triad of

1. Postinfectious peripheral arthritis
2. Uveitis / conjunctivitis
3. Urethritis / cervicitis

with characteristic skin lesions

M÷F = 98÷2

Types:

1. endemic (venereal): Chlamydia + Ureaplasma (males)
2. epidemic (postdysenteric): Shigella, Salmonella, Yersinia, Campylobacter (males + females)

Trigger: within a few weeks after infection of GU / GI tract; skeletal manifestations typically appear after urethral and ocular inflammation have subsided

• history of sexual exposure / diarrhea 3–11 days before onset of urethritis
• mucocutaneous lesions of coalescing pustules, vesicles, erosions (in up to 50%):
• balanitis circinata sicca (male)
• ulcerative vulvitis (females)
• keratosis blennorrhagicum = well-demarcated scaly hyperkeratotic + pustular papules coalescing to plaques

Location: palm, sole

• seronegative spondyloarthritis
• positive HLA-B27 in 76% → greater propensity for chronicity

Location: asymmetric mono- / pauciarticular with predilection for lower extremity (small joints of foot, calcaneus, ankle)

Spectrum: enthesitis, joint effusion, synovitis, bursitis, erosive + proliferative bone changes, diffuse soft-tissue edema with tenosynovitis of finger + toe

• polyarthritis
• articular soft-tissue swelling + joint space narrowing in 50% (particularly knee, ankle, foot)
• widening + inflammation of Achilles + plantar fascial tendons → heel swelling + retrocalcaneal bursitis (frequent)
• “fluffy” periosteal reaction (DISTINCTIVE) at metatarsal necks, proximal phalanges, calcaneal spur, tibia + fibula at ankle and knee
• juxtaarticular osteoporosis (rare in acute stage)

Chronic changes:

• recurrent joint attacks in a few cases
• calcaneal spur at insertion of plantar fascia + Achilles tendon
• periarticular deossification
• marginal erosions, loss of joint space
• bilateral sacroiliac changes indistinguishable from ankylosing / psoriatic spondylitis (in 10–40%)
• paravertebral ossification = isolated “floating osteophyte” usually in thoracolumbar area

Cx: gastric ulcer + hemorrhage; aortic incompetence; heart block; amyloidosis

DDx: Psoriasis (radiographically indistinguishable; no predilection for lower extremities, asymmetric involvement, clinical findings)