Bacteria can enter the joint by:

The bloodstream from an infection elsewhere (most common)
Direct penetration into the joint (arthrocentesis, arthroscopy, trauma)
A surrounding infection in the bone or tissue (uncommon, from osteomyelitis, septic bursitis, abscess).Microorganisms in the blood may come from infections elsewhere in the body such as wound infections, urinary tract infections, meningitis or endocarditis. Sometimes, the infection comes from an unknown location. Joints with preexisting arthritis, such as rheumatoid arthritis, are especially prone to bacterial arthritis spread through the blood. In addition, some treatments for rheumatoid arthritis can also increase a persons risk by causing an immunocompromised state. Intravenous drug use can cause endocarditis that spreads bacteria in the bloodstream and subsequently causes septic arthritis. Bacteria can enter the joint directly from prior surgery, intraarticular injection, trauma or joint prosthesis. Risk factors
In children, although septic arthritis occurs in healthy children and adolescents with no co-occurring health issues, there are certain risk factors that may increase the likelihood of acquiring septic arthritis. For example, children with renal osteodystrophy or renal bone disease, certain hematological disorders and diseases causing immune suppression are risk factors for childhood septic arthritis.The rate of septic arthritis varies from 4 to 29 cases per 100,000 person-years, depending on the underlying medical condition and the joint characteristics. For those with a septic joint, 85% of the cases have an underlying medical condition while 59% of them had a previous joint disorder. Having more than one risk factor greatly increases risk of septic arthritis. Age over 80 years
Diabetes mellitus
Osteoarthritis
Rheumatoid arthritis.
Nasal vestibulitis is the diffuse dermatitis of nasal vestibule. It is often caused by Staphylococcus aureus. It may be secondary to chronic rhinorrhea, nose picking or viral infections. In acute vestibulitis, the skin is red, swollen and tender. In chronic vestibulitis, induration of vestibular skin and crusting is seen. Antibiotic steroid ointment is sometimes helpful. Chronic fissures can be cauterized with Silver Nitrate. == References ==