The most common type of nontraumatic acute monoarthritis in young, sexually active persons
a) Lyme disease
b) Nongonococcal septic arthritis
c) Gonococcal arthritis
d) gout
e) Spontaneous osteonecrosis
Answer:
c) Gonococcal arthritis
Explanation
Gonococcal arthritis is the most common type of nontraumatic acute monoarthritis in young, sexually active persons in the United States. It is three to four times more common in women than in men.
Nongonococcal septic arthritis, the most destructive type, generally is monoarticular (80 percent of cases) and most often affects the knees (50 percent of cases).
Staphylococcus aureus is the most common pathogen in nongonococcal septic arthritis (60 percent in some series), but non-group-A beta-hemolytic streptococci, gram-negative bacteria, and Streptococcus pneumoniae can be present. Anaerobic and gram-negative infections are common in immunocompromised persons. Inflammation of a single large joint, especially the knee, may be present in Lyme disease. Mycobacterial, fungal, and viral infections are rare. Monoarticular inflammation can be the initial manifestation of human immunodeficiency virus (HIV) infection.
Many types of crystals can trigger acute monoarthritis, but monosodium urate (which causes gout) and calcium pyrophosphate dihydrate (CPPD, which causes pseudogout) are the most common. Calcium oxalate (especially in patients who are receiving renal dialysis), apatite, and lipid crystals also elicit acute monoarthritis. Transient arthritis sometimes results from intra-articular injection of corticosteroids. Osteoarthritis may worsen suddenly and manifest as pain and effusion. Spontaneous osteonecrosis may occur in patients with risk factors such as alcoholism or chronic corticosteroid use. Aseptic loosening is often the source of pain in a prosthetic joint. Infection, commonly from a skin source, is also possible and requires urgent attention.