Gonococcal arthritis
Gonococcal arthritis is inflammation of a joint due to a gonorrhea infection. Gonococcal arthritis starts when Neisseria gonorrhoeae are passed through vaginal, anal, or oral sex.
In contrast to nongonococcal bacterial arthritis, gonococcal arthritis usually occurs in otherwise healthy individuals. Host factors, however, influence the expression of the disease: gonococcal arthritis is two to three times more common in women than in men, is especially common during menses and pregnancy, and is rare after age 40.
Gonococcal arthritis is also common in men who have sex with men, whose high incidence of asymptomatic gonococcal pharyngitis and proctitis predisposes them to disseminated gonococcal infection.
Recurrent disseminated gonococcal infection should prompt testing of the patient’s CH50 level to evaluate for a congenital deficiency of a terminal complement component (C5, C6, C7, or C8).
Symptoms and Signs
One to 4 days of migratory polyarthralgias involving the wrist, knee, ankle, or elbow are common at the outset. Thereafter, two patterns emerge.
The first pattern is characterized by tenosynovitis that most often affects wrists, fingers, ankles, or toes and is seen in 60% of patients.
The second pattern is purulent monoarthritis that most frequently involves the knee, wrist, ankle, or elbow and is seen in 40% of patients.
Less than half of patients have fever, and less than one-fourth have any genitourinary symptoms.
Most patients will have asymptomatic but highly characteristic skin lesions that usually consist of 2 to 10 small necrotic pustules distributed over the extremities, especially the palms and soles.
Diagnosis
The peripheral blood leukocyte count averages about 10,000 cells/mcL and is elevated in less than one-third of patients. The synovial fluid white blood cell count usually ranges from 30,000 to 60,000 cells/mcL. The synovial fluid Gram stain is positive in one-fourth of cases and culture in less than half. Positive blood cultures are uncommon. Urethral, throat, cervical, and rectal cultures should be done in all patients, since they are often positive in the absence of local symptoms. Urinary nucleic acid amplification tests have excellent sensitivity and specificity for the detection of Neisseria gonorrhoeae in genitourinary sites.
Radiographs are usually normal or show only soft tissue swelling.
Differential diagnosis
Reactive arthritis can produce acute monoarthritis, urethritis, and fever in a young person but is distinguished by negative cultures and failure to respond to antibiotics.
Lyme disease involving the knee is less acute, does not show positive cultures, and may be preceded by known tick exposure and characteristic rash. The synovial fluid analysis will exclude gout, pseudogout, and nongonococcal bacterial arthritis.
Rheumatic fever and sarcoidosis can produce migratory tenosynovitis but have other distinguishing features.
Infective endocarditis with septic arthritis can mimic disseminated gonococcal infection.
Meningococcemia occasionally presents with a clinical picture that resembles disseminated gonococcal infection; blood cultures establish the correct diagnosis.
Early hepatitis B infection is associated with circulating immune complexes that can cause a rash and polyarthralgias. In contrast to disseminated gonococcal infection, the rash in hepatitis B is urticarial.
Treatment
In most cases, patients in whom gonococcal arthritis is suspected should be admitted to the hospital to confirm the diagnosis, to exclude endocarditis, and to start treatment. The recommendation for initial treatment is to give azithromycin (1 g orally as a single dose) and a third-generation cephalosporin: ceftriaxone, 1 g intravenously daily (or every 12 hours if concomitant meningitis or endocarditis is suspected); or cefotaxime, 1 g intravenously every 8 hours; or ceftizoxime, 1 g intravenously every 8 hours. Azithromycin enhances eradication of gonorrhea and covers potential coinfection with Chlamydia