What is the most common cause of infectious arthritis in young adults?

What is the most common cause of infectious arthritis in young adults?

• A. Staphylococcus aureus
• B. Neisseria gonorrhoeae
• C. Streptococcus pneumoniae
• D. Borrelia burgdorferi

Answer: (B)

Neisseria gonorrhoeae is the most common cause of infectious arthritis in young, sexually active adults because gonorrheal infection often disseminates after a mucosal infection and seeds the joints. This population has higher rates of gonorrhea, so disseminated gonococcal infection presenting with migratory joint pain, tenosynovitis, and sometimes purulent arthritis becomes the leading cause of septic arthritis in this age group. It’s important to contrast with the broader pattern: Staphylococcus aureus is the single most common cause of septic arthritis across all ages, but in young adults the gonococcal form predominates. Other organisms like Streptococcus pneumoniae and Borrelia burgdorferi can cause arthritis but are less typical in this age group and clinical context.

Neisseria gonorrhoeae is the most common cause of infectious arthritis in young, sexually active adults because gonorrheal infection often disseminates after a mucosal infection and seeds the joints. This population has higher rates of gonorrhea, so disseminated gonococcal infection presenting with migratory joint pain, tenosynovitis, and sometimes purulent arthritis becomes the leading cause of septic arthritis in this age group. It’s important to contrast with the broader pattern: Staphylococcus aureus is the single most common cause of septic arthritis across all ages, but in young adults the gonococcal form predominates. Other organisms like Streptococcus pneumoniae and Borrelia burgdorferi can cause arthritis but are less typical in this age group and clinical context.