Infectious disorders D. mycobacterial, fungal, and parasitic arthritis

Osteoarticular involvement occurs in about 5% of patients with tuberculosis (TB), with estimated percentage ranging from about 2% of all TB cases in the United States to more than 6% in developing countries. Pott's disease (spinal tuberculosis) is the most common form of osteoarticular infection with Mycobacterium tuberculosis. Articular TB is usually due to reactivation of a hematogenously seeded focus and need not be associated with active disease elsewhere; it can also spread from adjacent osteomyelitis. Lengthy delays in diagnosis-on the order of 3 to 4 years-are reported. Poncet's disease is a form of reactive arthritis occurring during active TB. Mycobacterium marinum infection is often associated with such aquatic exposures as fish tank water, fish hook lacerations, skin punctures by fish spines, and cuts from boat motor propellers. The syndrome of erythema nodosum leprosum, manifested as crops of subcutaneous nodules, fever, and arthralgia or arthritis, occurs in patients with lepromatous leprosy. Valley fever (or desert rheumatism) are terms used for an immune complex-mediated syndrome associated with cocciodiomycosis infection. This syndrome, which is self-limited, is characterized by joint complaints, fever, rash, erythema nodosum, erythema multiforme, eosinophilia, and hilar adenopathy. Sporotrichosis, which usually presents as a painful erythematous nodule at the site of a skin wound. Inoculation of the organism Sporothrix schenckii into the skin through gardening or landscape exposures to soil or plant material is the mode of pathogenesis (the classic exposure is to a rose thorn).