In the pathogenesis of spondyloarthropathies, infection and gut inflam
mation are the most important external triggering factors. Early antim
icrobial therapy to treat urethritis caused by Chlamydia trachomatis i
s effective in preventing a recurrent reactive arthritis: When the art
hritis appear, a short term conventional antimicrobial therapy is unab
le to modify its course. In acute chlamydia arthritis, patients benefi
t from a prolonged (3-month) treatment with tetracycline, while such a
treatment has not proved to be effective in enteroarthritis or in chr
onic forms of reactive arthritis, The role of sulfasalazine in the tre
atment of patients with spondyloarthropathies is controversial. It mig
ht modify the disease course during acute and chronic reactive arthrit
is, and is working for patients with ankylosing spondylitis, especiall
y patients with peripheral arthritis. Data showing an effect of sulfas
alazine in the prevention of chronic spondyloarthropathy or in modific
ation of the long-term prognosis of ankylosing spondylitis are, howeve
r, lacking.