Triggered by chlamydial urethritis and enteric pathogens like shigella, salmonella, Yersinia, campylobacter, and HIV infection (Bull Rheum Dis 1990;39[5]:1). Associated with HLA B27-like ankylosing spondylitis (Ann IM 1976;84:8). Male:female 9:1
Sx:2- to 4-wk incubation after trigger (see above). First urethritis (85%), cervicitis, and/or prostatitis; then red eye (conjunctivitis); then weeks later, arthritis and arthralgias (99%), esp peripheral and in lower extremities, esp heels, knees, ankles, low back
Si:Peripheral arthritis and purulent urethral discharge (95%); red eye from conjunctivitis (40%) or uveitis (8%); fever (37%); painless skin or mucous membrane lesions (32%), esp circinate balanitis and keratoderma blennorrhagica (looks like pustular psoriasis)
Aortitis (1%); heart block (1%)
r/o chronic Lyme arthritis, gonorrhea, erythema multiforme variants, Behçets syndrome, psoriasis, ankylosing spondylitis
Lab:
Joint fluid:WBC = 5000-50 000, mostly polys but lower % than gonorrhea with more monos
Serol:RA titer negative; HLA B27 60-75% sensitivity, 8% specificity
Xray:Periosteal new bone formation along shafts, eg, of phalanges
Rx: Tetracycline rx of presumed chlamydia of patient and partner (Bull Rheum Dis 1992;40[6]:1) NSAIDs as in ankylosing spondylitis (Ankylosing Spondylitis)