Infectious Arthritis Flashcards
Acute bacterial arthritis is a medical emergency that requires what 3 things?
1) Rapid, accurate Dx
2) Immediate treatment
3) Appropriate consultation with additional specialists as needed
What are most instances of native joint infection the result of?
Bacteremic seeding
What is the most frequent microorganism in adult nongonococcal septic arthritis?
Staphylococcus aureus
The initial selection of an Abx regimen should be what? and why?
Broad enough to take into account host factors, clinical characteristics, likely causative microorganism, and regional antibiotic sensitivity data pending confirmation of bacteria by culture and sensitivities.
An infection joint is treated how?
Adequate drainage and an Abx course that is sufficiently long to cure the infection
When is surgical drainage of a joint indicated?
Only if needle aspirations are unsuccessful or impractical
What are poor prognostic factors in bacterial joint infection? (3)
Old age, underlying rheumatoid arthritis, and infection of a prosthetic joint
What is a reasonable option for selected patients with early prosthetic joint infections?
DAIR - Debridement, abx, implant retention
What do late prosthetic joint infections require?
Abx treatment that is directed at the isolated microorganism and the complete removal of the infected prosthesis before reimplantation of a new prosthesis in a one-stage or two-stage operation
What reduces the risk of a prosthetic joint infection?
Thorough pre-op eval, perioperative use of abx, careful use of abx prophylaxis when a patient with a prosthesis is exposed to transient bacteremia
Clinical evidence does not support the use of antibiotic prophylaxis in what?
Most dental procedures
Lyme dz is caused by infection with what?
Tick-transmitted spirochetes of the genus Borrelia Burgdorferi sensu alto; worldwide distribution
Lyme dz has characteristic pattern os signs and sx’s, starting with what?
Expanding macular skin lesion erythema migrans
Earlier recognition and treatment of lyme dz has led to a decline in the incidence of?
Carditis, acute necrologic dz, late dz manifestations
Musucloskeletal manifestations occur in more than 50% of lyme dz patients and at all stages of the infection, what is a sign of late dz and uncommon? (<10% of patients)
Frank Arthritis
The dx of Lyme Dz should be suspected in what type of a patient?
Patient who lives, works, or vacations in an endemic area the presents with signs and symptoms of B. Burgdorferi (duh)
What can be negative in early infection but become positive in most patients? When will they become positive?
Two-tiered serologic tests (enzyme-linked immunosorbent assay and immunoblot); become positive in most patients >1 month duration
Most patients are cured within 2-4 weeks of abx therapy but what may happen with lyme disease resolution?
Disease resolution may take longer than the duration of therapy and irreversible damage may occur
Abx-refractory arthritis occurs in less than 10% of patients with Lyme arthritis, how is it treated and how long til resolution?
It responds to disease modifying antirheumatic drugs, and typically resolves within 4-5 years
What is post-lyme dz syndrome?
Persistent debilitating complaints of fatigue, mild cognitive dysfunction, and musculoskeletal pain after antibiotic tx (minority of patients)
What cannot be detected in patients with post-lyme dz syndrome? How is it treated?
B. Burgdorferi; Controlled tx trials show no benefit of prolonged abx over placebo
Why is the global incidence of TB increasing?
Expanding human HIV pandemic and growing problem of antituberculous drug resistance; rheumatologists have seen an increase in TB dz in response to the expanded use of anti-TNF agents
What does MSK TB usually present as?
Chronic localized infection, most commonly involving the spine, less often the hip or knee
How is Dx of MSK TB made?
May be very difficult and may require Bx for histopathology and culture of bone/synovium; rapid dx test techniques have not yet proven reliable in bone and joint specimens
What is the tuberculin skin test helpful with? What is it limited by? What may be better?
In identifying latent TB before treatment with anti-TNF agents, but it is limited by false + and false - results; availability of interferon gamma release assays may be a more useful screening procedure
What does tx require for MSK TB?
Multiple agents selected on the basis of susceptibility testing for 6-9 months and has been complicated by the increasing incidence of drug resistance
What is becoming and important pathogen to recognize in the face of biologic therapy for rheumatic dzs?
Nontuberculous Mycobacteria
What is an infrequent but clinically important infection due to bone and joint involvement?
Fungi
Fungal infections are often described as what in regards to inset?
Indolent in onset and may masquerade as other disorders
Travel and immigration means what in regard to fungal etiologies?
It affects the geographic localization of fungal infections, which may now be seen in nonendemic areas
Diagnosis may be assisted by clinical presentation and serologic testing, but what is key for fungal infections?
Examination and culture of infected tissue
New antifungal therapies have broadened effective otions, but what 3 things must be considered in treating a fungal infection?
Choice of drugs, duration of treatment, and surgical debridement for optimal outcomes
What predisposes patients to fungal infections that often result in more acute and widely disseminated dz?
Immunocompromised including antirheumatic biologic therapies
What is not useful in fungal infection?
Screening and/or prophylactic therapy for ICP patients; so a high index of suspicion must be maintained when patients present with an acute febrile illness
In patients with HIV living longer as a result of effective tx, what is increasing?
The challenges of HIV-associated rheumatic manifestations
Certain dzs tend to be particular to an HIV infection like what?
HIV-associated arthritis, diffuse infiltrative lymphocytosis syndrome (DILS), HIV associated polymyositis
CD4 mediated diseases such as RA and SLE go into remission with what condition and then flare with what condition?
Remission with disease activity and flare with antiretroviral tx
Effective antiretroviral tx has resulted in dzs like DILS and late opportunistic infection doing what but what happens because of this?
They decrease in prevalence but it is now associated with new side effecs like osteonecrosis, mypoathy, and rhabdo
What has led to a new spectrum of AI and autoinflammatory diseases that require special attention?
Immune reconstitution after antiretroviral therapy
Acute-onset, symmetric polyarthritis can be caused by viral infections, what is this often accompanied with?
Rash
In regards to viral infections what must you always take?
Exposure, travel, occupation, and vaccination hx
What is the most common viral arthritis in the US?
Parvo B19
In adults with parvo B19 what can be subtle or absent?
Rash
Rubella arthritis occurs in what group of people?
Young athletes
Rubella vaccination has reduced the overall incidence of rubella infection but did what?
Shifted the people incidence of rubella infections to young adults
What can occur after rubella vaccination?
Arthralgia, Arthritis, or neuropathic pain; usually self limited
Alphaviruses are mosquito-borne causes of arthritis and rash, how do outbreaks occur? Who should this be considered in?
In endemic areas associated with rising mosquito populations and should be considered in travelers entering the US
How does Hep B virus infection present?
Arthritis-urticaria syndrome
Hep C virus infection causes what? How does this present?
Cryoglobulinemia and vasculitis, usually with palpable purport of the lower legs
The history of risk behaviors associated with infection of what virus may be remote?
Hep C (stupid question..)
ARF is a delayed nonsupparative sequel of a pharyngeal infection with what?
Group A Streptococci
Even though a dramatic decline in the severity and mortality of ARF has been noted, what has been reported?
Resurgence in the US
How can the incidence of subsequent ARF after streptococcal pharyngitis be decreased? What can be done to prevent recurrence?
Adequate treatment; Appropriate antimicrobial prophylaxis prevents recurrence of disease in known patients with ARF.
What is the clinical presentation of ARF?
It varies (Got ya! Nichols style)
How is ARF diagnosed? Why is this done?
Because of the lack of a single pathognominic feature, the development of the revised Jones criteria are used for diagnosis
What are the terms migratory and migrating used for? What do they mean?
To describe the polyarthritis of ARK, but these designations do not signify that inflammation disappears in one joint when it appears in another, it means that the various localizations usually overlap in time, and the onset, as opposed to the full course, migrates from joint to joint.
What have many investigators suggested about poststreptococcal migratory arthritis (PMA) in both children and adults?
That PMA in absence of carditis might be an entity distinct from ARF, although these features may be seen.
What should migratory arthritis without evidence of other major Jones criteria but supported with two minor be considered?
ARF, in children specifically
Antibiotic prophylaxis with penicillin should be started immediately after resolution of the acute episode of ARF, what is the optimal regimen?
Oral Penicillin VK (250,000 U twice a day) or parenternal penicillin G, 1.2 million U IM every 4 weeks.
