65: Psoriatic Arthritis and Reactive Arthritis

Question 1

What are the classification criteria for Psoriatic Arthritis (PsA) according to CASPAR?

Answer 1

The CASPAR criteria include:
1. Psoriasis (must be current) - 2 points
2. Personal history of psoriasis - 1 point
3. Family history (first- or second-degree relative) - 1 point
4. Nail dystrophy typical of psoriasis (onycholysis, pitting, hyperkeratosis) - 1 point
5. Negative rheumatoid factor (any method except latex) - 1 point
6. Dactylitis (current or historical) - 1 point
7. Juxtaarticular new bone formation (defined ossification near joint margins excluding osteophytes) - 1 point

A total score of 3 or more points is required for diagnosis.

Question 2

What is the prevalence of Psoriatic Arthritis (PsA) in the general population?

Answer 2

PsA prevalence is highly variable, estimated to be between 0.02% to 0.25% in the general population. It occurs most frequently in individuals with psoriasis, with a prevalence of 3.2% to 41% in that population.

Question 3

What are the clinical predictors of Psoriatic Arthritis (PsA)?

Answer 3

Clinical predictors of PsA include:
- Nail psoriasis
- Severe psoriasis
- Scalp psoriasis
- Intergluteal or perianal psoriasis
- Presence of uveitis

These factors are associated with a higher risk of developing PsA.

Question 4

What are the cutaneous findings associated with Psoriatic Arthritis (PsA)?

Answer 4

Cutaneous findings associated with PsA include:
- Scalp and intergluteal psoriasis are more likely to be associated with PsA risk.
- Nail disease has a prevalence of 40% in psoriasis and is a known risk factor for PsA, with an overall prevalence of 80%.
- Both nail plate and nail matrix are affected, with nail pitting being the most common finding.
- There is an association between nail psoriasis and distal interphalangeal joint arthritis.

Question 5

What are the key clinical predictors of Psoriatic Arthritis (PsA) and their significance?

Answer 5

Key clinical predictors of PsA include:
- Nail Psoriasis: Indicates a higher risk of developing PsA.
- Severe Psoriasis: Associated with increased risk.
- Scalp, Intergluteal, or Perianal Psoriasis: These areas are linked to higher PsA risk.
- Presence of Uveitis: Also a significant predictor.

These predictors help in early diagnosis and treatment, which are crucial for preventing damage and improving long-term outcomes.

Question 6

How does the prevalence of nail disease relate to Psoriatic Arthritis in patients with psoriasis?

Answer 6

Nail disease prevalence in psoriasis patients is significant:
- Prevalence of Nail Disease: 40% in psoriasis patients.
- Known Risk Factor for PsA: Nail disease is a recognized risk factor for developing PsA.
- Overall Prevalence of PsA: 80% of patients with nail disease may develop PsA.

This relationship highlights the importance of monitoring nail health in psoriasis patients for early intervention.

Question 7

What is the estimated prevalence of Psoriatic Arthritis in the general population and among those with psoriasis?

Answer 7

The estimated prevalence of Psoriatic Arthritis (PsA) is:
- General Population: 0.02% to 0.25%.
- Among People with Psoriasis: 3.2% to 41%.

This variability underscores the need for awareness and screening in populations at risk, particularly those with psoriasis.

Question 8

What are the implications of early diagnosis and treatment of Psoriatic Arthritis?

Answer 8

Early diagnosis and treatment of Psoriatic Arthritis (PsA) are crucial for:
1. Preventing Damage: Early intervention can prevent joint and tissue damage.
2. Improving Function: Timely treatment helps maintain mobility and quality of life.
3. Long-term Outcomes: Effective management can lead to better long-term health outcomes for patients.

These factors highlight the importance of recognizing symptoms and risk factors early in the disease process.

Question 9

A patient with psoriasis presents with nail pitting and distal interphalangeal joint arthritis. What is the significance of these findings in the context of Psoriatic Arthritis (PsA)?

Answer 9

Nail pitting and distal interphalangeal joint arthritis are significant as they are strongly associated with PsA. Nail psoriasis is a known risk factor for PsA, with a prevalence of 80% in PsA patients.

Question 10

A patient with PsA has a history of scalp psoriasis and severe nail disease. How do these factors influence the risk of developing PsA?

Answer 10

Scalp psoriasis and severe nail disease are significant risk factors for PsA. Nail disease has a prevalence of 80% in PsA patients and is strongly associated with distal interphalangeal joint arthritis.

Question 11

What are the common noncutaneous findings preceding the diagnosis of Psoriatic Arthritis (PsA)?

Answer 11

PsA is preceded by nonspecific musculoskeletal and systemic symptoms such as:
- Joint pain
- Fatigue
- Stiffness

These symptoms typically occur in the year prior to diagnosis.

Question 12

What is the prevalence of dactylitis in Psoriatic Arthritis and what does it indicate?

Answer 12

Dactylitis has a prevalence of 20% to 59% in PsA and is a sign of disease severity associated with radiographic damage. It involves full-thickness inflammation of a digit (finger or toe) and affects the joints, entheses, and subcutaneous tissues of the digits.

Question 13

What is enthesitis and its clinical significance in Psoriatic Arthritis?

Answer 13

Enthesitis refers to the tenderness at the insertion sites of tendons, ligaments, and joint capsules on bone. It occurs clinically in 35% of people with PsA, with an annual incidence of 0.9%. The most common sites of involvement include:
- Achilles tendons
- Plantar fascia
- Lateral epicondyles at the elbows.

Question 14

What are the risk factors associated with axial Psoriatic Arthritis?

Answer 14

Risk factors for axial PsA include:
- Presence of onycholysis
- Inflammatory back pain symptoms
- PsA duration or young age at onset
- Positive HLA-B27
- Inflammatory bowel disease

Axial PsA with isolated spondylitis is about 4 times more likely to be asymptomatic than axial PsA with sacroiliitis.

Question 15

What are the eye diseases associated with Psoriatic Arthritis?

Answer 15

Eye diseases in PsA include:
- Blepharitis
- Dry eye
- Conjunctivitis
- Uveitis
- Episcleritis
- Scleritis
- Keratoconjunctivitis sicca
- Keratitis

Uveitis occurs in 7% to 25% of people with PsA, which is less than in ankylosing spondylitis (AS) but higher than in psoriasis.

Question 16

What is the prevalence of dactylitis in patients with Psoriatic Arthritis and its significance?

Answer 16

Dactylitis has a prevalence of 20% to 59% in PsA and is a sign of disease severity associated with radiographic damage, affecting joints, entheses, and subcutaneous tissues of the digits.

Question 17

How is enthesitis clinically diagnosed in patients with Psoriatic Arthritis?

Answer 17

Enthesitis is clinically diagnosed as tenderness to pressure at entheseal insertion sites, occurring in 35% of people with PsA, with an annual incidence of 0.9%.

Question 18

What are the risk factors associated with axial Psoriatic Arthritis?

Answer 18

Risk factors for axial PsA include the presence of onycholysis, inflammatory back pain symptoms, PsA duration/young age at onset, positive HLA-B27, and inflammatory bowel disease.

Question 19

What is the estimated prevalence of eye disease in patients with Psoriatic Arthritis compared to those with psoriasis?

Answer 19

A third of people with PsA experience eye disease, while only 10% of people with psoriasis do. Uveitis is estimated at 7% to 25% in PsA, which is higher than in psoriasis but lower than in ankylosing spondylitis (AS).

Question 20

A patient with PsA has axial involvement. What are the clinical and genetic risk factors for this subtype?

Answer 20

Risk factors include inflammatory back pain symptoms, onycholysis, young age at onset, positive HLA-B27, and inflammatory bowel disease.

Question 21

A patient with PsA reports inflammatory back pain and has a history of onycholysis. What is the likely subtype of PsA, and what are the risk factors?

Answer 21

The likely subtype is axial PsA. Risk factors include onycholysis, inflammatory back pain symptoms, PsA duration, young age at onset, positive HLA-B27, and inflammatory bowel disease.

Question 22

A patient with PsA presents with dactylitis. What imaging findings would support this diagnosis?

Answer 22

Imaging findings supporting dactylitis include diffuse extracapsular soft tissue edema, diffuse or focal increased bone marrow edema, enthesitis at the collateral ligament and extensor tendon insertions, flexor tenosynovitis, and synovitis.

Question 23

What is the relationship between psoriasis, PsA, and inflammatory bowel disease in terms of genetic determinants?

Answer 23

Psoriasis, PsA, and inflammatory bowel disease partially overlap in their genetic determinants, immune effectors, and therapeutics.

Question 24

What are some medical risk factors and comorbidities associated with PsA?

Answer 24

Medical risk factors and comorbidities associated with PsA include:
- Cardiovascular risk (myocardial infarction, congestive heart failure)
- Cerebrovascular events
- Obesity, type 2 diabetes mellitus, non-alcoholic fatty liver disease, and metabolic syndrome.

Question 25

What is the prevalence of PsA in first-degree relatives and the significance of HLA-B27?

Answer 25

The prevalence of PsA in first-degree relatives is **5.5%**, which is around **100 times higher** than in the general population. **HLA-B27** has the strongest evidence for being a genetic risk factor for PsA, with a prevalence in PsA ranging from **19% to 35%**.

Question 26

What are the key components of the adaptive immune system responses in PsA?

Answer 26

The adaptive immune system responses in PsA are characterized by: - Selective transcription of mediators favoring **Th1** and **Th17** cells. - **IL12/Tbet signaling** leading to Th1 cell differentiation and proliferation. - **RORγt signaling** in the presence of **IL23** leading to Th17 cell differentiation and proliferation.

Question 27

What are the implications of delayed diagnosis in early PsA?

Answer 27

Studies indicate that a delay in diagnosis of **6 months or more** is linked to significantly more **disability** in people with PsA. Early diagnosis is crucial to manage associated manifestations such as lower extremity arthritis, uveitis, and enthesitis, as well as health risk factors like cardiovascular disease and metabolic syndrome.

Question 28

What criteria are used for the classification of PsA?

Answer 28

The **CASPAR criteria** are used for the classification of PsA and for participant inclusion in PsA clinical trials. Additionally, laboratory tests for **rheumatoid factor** and **anticyclic citrullinated peptides** are also utilized.

Question 29

What are the implications of delaying the diagnosis of PsA for more than 6 months?

Answer 29

Delaying the diagnosis of PsA for more than 6 months is linked to significantly more disability in affected individuals. This delay can lead to worsening symptoms and complications, including associated manifestations such as lower extremity arthritis, uveitis, sacroiliitis, and enthesitis, as well as increased health risk factors like cardiovascular disease and metabolic syndrome.

Question 30

How do genetic factors contribute to the risk of developing PsA?

Answer 30

Genetic factors contribute to the risk of developing PsA through several mechanisms: 1. **HLA-B27**: This allele has the strongest evidence as a genetic risk factor, with a prevalence of 19% to 35% in PsA patients. 2. **Family History**: The prevalence of PsA is significantly higher (around 100 times) in first-degree relatives, with a baseline risk of 5.5%. 3. **Other Genetic Factors**: Factors encoding immune system functions, including antigen presentation and processing, also play a role in the pathogenesis of PsA.

Question 31

What role does the adaptive immune system play in PsA?

Answer 31

The adaptive immune system in PsA is characterized by selective transcription of mediators that favor the differentiation and proliferation of specific T cell subsets: - **Th1 Cells**: Mediated by IL12/Tbet signaling, leading to Th1 cell differentiation. - **Th17 Cells**: Mediated by RORγt signaling in the presence of IL23, leading to Th17 cell differentiation. These responses are crucial for the inflammatory processes observed in PsA.

Question 32

What are the CASPAR criteria and their significance in PsA?

Answer 32

The CASPAR criteria are a set of classification criteria used for diagnosing PsA and determining participant inclusion in clinical trials. These criteria help ensure that individuals diagnosed with PsA meet specific clinical and laboratory parameters, facilitating more accurate research and treatment approaches.

Question 33

A patient with PsA has severe enthesitis. What genetic and immune factors contribute to this condition?

Answer 33

Genetic factors include HLA-B27. Immune factors involve TNF-induced NF-kB signaling and adaptive immune responses favoring Th1 and Th17 cells, mediated by IL12/Tbet and RORγt signaling.

Question 34

A patient with PsA has metabolic syndrome. What comorbidities are commonly associated with PsA, and how do they impact management?

Answer 34

Comorbidities include cardiovascular risk (myocardial infarction, congestive heart failure), cerebrovascular events, obesity, type 2 diabetes mellitus, and non-alcoholic fatty liver disease. These comorbidities necessitate a multidisciplinary approach to management.

Question 35

A patient with PsA has a family history of the disease. What is the prevalence of PsA in first-degree relatives, and what genetic marker is most strongly associated?

Answer 35

The prevalence of PsA in first-degree relatives is 5.5%, with a 100-fold increased risk. The genetic marker most strongly associated is HLA-B27.

Question 36

A patient with PsA has been diagnosed with inflammatory bowel disease (IBD). What is the relationship between PsA and IBD, and how does it influence treatment?

Answer 36

PsA and IBD partially overlap in genetic determinants, immune effectors, and therapeutics. Treatment may involve TNF inhibitors like adalimumab and infliximab, which are effective for both conditions.

Question 37

What is the significance of genotyping for HLA-B27 in patients with psoriasis?

Answer 37

Genotyping for **HLA-B27** has clinical and prognostic value because **HLA-B27-positive individuals** are at higher risk for early PsA, axial PsA, severe enthesitis, and uveitis.

Question 38

What are the common differential diagnoses to consider in patients with psoriasis?

Answer 38

Common differential diagnoses include: 1. **Rheumatoid arthritis** - usually positive for rheumatoid factor or anti-CCP.

Question 39

What is the significance of genotyping for HLA-B27 in patients with psoriasis?

Answer 39

Genotyping for HLA-B27 has clinical and prognostic value because HLA-B27-positive individuals are at higher risk for early PsA, axial PsA, severe enthesitis, and uveitis.

Question 40

What are the common differential diagnoses to consider in patients with psoriasis?

Answer 40

Common differential diagnoses include: 1. Rheumatoid arthritis - usually positive for rheumatoid factor or anti-CCP. 2. Reactive arthritis - more likely to occur after a GI or sexually transmitted infection. 3. Gout - more common in people with psoriasis due to increased skin turnover and cardiovascular comorbidities. 4. Osteoarthritis (OA) - high prevalence and overlapping comorbidities, usually less inflammatory than PsA, and lacks PsA-specific manifestations like dactylitis, enthesitis, and/or spondylitis.

Question 41

What is the clinical significance of delayed PsA diagnosis and treatment?

Answer 41

Delayed PsA diagnosis and effective treatment are associated with disability and radiographic damage. There is a critical window of opportunity of about 6 months to initiate therapy to maximize chances of minimal disease damage.

Question 42

What are the current treatment recommendations for PsA?

Answer 42

Current treatment recommendations for PsA include: 1. Begin treatment according to the clinical phenotype. 2. Assess disease activity every 3 months at least in the beginning or until the treatment target is achieved. 3. The goal of therapy is to achieve minimal or low disease activity and escalate therapy until this goal is achieved. 4. Disease-modifying antirheumatic drugs (DMARDs) such as methotrexate, sulfasalazine, and leflunomide are recommended as standard of care.

Question 43

What is the window of opportunity for initiating therapy in PsA to minimize disease damage?

Answer 43

There is a window of opportunity of about 6 months to initiate therapy in PsA to maximize the chances of achieving minimal disease damage.

Question 44

What genetic marker is associated with uveitis in PsA?

Answer 44

The genetic marker HLA-B27 is associated with uveitis in PsA. HLA-B27-positive individuals are at higher risk for early PsA, axial PsA, severe enthesitis, and uveitis.

Question 45

What are the potential consequences of delayed diagnosis in PsA?

Answer 45

Delayed diagnosis can lead to increased disability, radiographic damage, and missed opportunities to initiate therapy during the critical six-month window to minimize disease damage.

Question 46

What is the preferred DMARD for peripheral spondyloarthritis in the treatment of psoriatic arthritis?

Answer 46

Sulfasalazine has been shown to improve psoriatic joint swelling with no effect on psoriasis or enthesitis, making it the preferred DMARD in peripheral spondyloarthritis.

Question 47

Which class of medications is generally considered first-line biologic agents for psoriatic arthritis?

Answer 47

TNF inhibitors (adalimumab, certolizumab, golimumab, etanercept, infliximab) are generally the first-line biologic agents and have been used for PsA for almost 2 decades.

Question 48

What are the effects of Apremilast in the treatment of psoriatic arthritis?

Answer 48

Apremilast is a selective inhibitor of the enzyme phosphodiesterase 4 (PDE4) and is a targeted synthetic disease-modifying medication with moderate effects for PsA affecting skin, nails, arthritis, enthesitis, and dactylitis.

Question 49

What is the role of IL17 inhibitors in the treatment of psoriasis and psoriatic arthritis?

Answer 49

IL17 inhibitors are the most efficacious medication class approved for psoriasis. Secukinumab and ixekizumab are both IL17 inhibitors, with Secukinumab labeled for PsA and AS, in addition to psoriasis.

Question 50

What is the significance of Tofacitinib in the treatment of psoriatic arthritis?

Answer 50

Tofacitinib, a jak/stat inhibitor, was recently labeled for psoriatic arthritis and ulcerative colitis, indicating its role in managing these conditions.

Question 51

Which medications are effective for PsA-associated manifestations of uveitis and inflammatory bowel disease?

Answer 51

Adalimumab and infliximab are effective for PsA-associated manifestations of uveitis and inflammatory bowel disease.

Question 52

What is the role of sulfasalazine in the treatment of peripheral spondyloarthritis?

Answer 52

Sulfasalazine has been shown to improve psoriatic joint swelling with no effect on psoriasis or enthesitis. It is considered the preferred DMARD in peripheral spondyloarthritis.

Question 53

How do TNF inhibitors compare to other treatment options for PsA?

Answer 53

TNF inhibitors (adalimumab, certolizumab, golimumab, etanercept, infliximab) are generally the first-line biologic agents for PsA and have been used for almost 2 decades. They are effective for both PsA and associated conditions like uveitis and inflammatory bowel disease.

Question 54

What are the clinical implications of using IL17 inhibitors for psoriasis and psoriatic arthritis?

Answer 54

IL17 inhibitors, such as secukinumab and ixekizumab, are the most efficacious medication class approved for psoriasis. Secukinumab is labeled for both PsA and AS, while ixekizumab is approved for psoriasis and psoriatic arthritis and is being evaluated in phase III clinical trials for AS.

Question 55

What is the significance of apremilast in the management of PsA?

Answer 55

Apremilast is a selective inhibitor of the enzyme phosphodiesterase 4 (PDE4), and it is a targeted synthetic disease-modifying medication with moderate effects for PsA, particularly for skin, nails, arthritis, enthesitis, and dactylitis.

Question 56

What are the potential risks associated with using antimalarials like hydroxychloroquine in patients with PsA?

Answer 56

Antimalarials, such as hydroxychloroquine, are not used in PsA due to the potential for worsening or precipitating the development of psoriasis.

Question 57

What alternative treatment options are recommended for a patient with PsA showing no improvement with methotrexate?

Answer 57

Alternative treatments include TNF inhibitors (e.g., adalimumab, certolizumab) and IL17 inhibitors (e.g., secukinumab, ixekizumab), which are effective for enthesitis.

Question 58

What are the first-line biologic agents for a patient with PsA being considered for biologic therapy?

Answer 58

First-line biologic agents include TNF inhibitors (e.g., adalimumab, infliximab). These agents are also effective for PsA-associated uveitis and inflammatory bowel disease.

Question 59

What are the limitations of sulfasalazine in the treatment of PsA?

Answer 59

Sulfasalazine improves psoriatic joint swelling but has no effect on psoriasis or enthesitis. It is the preferred DMARD for peripheral spondyloarthritis.

Question 60

What is the mechanism of action of apremilast, and what symptoms does it target?

Answer 60

Apremilast is a selective inhibitor of the enzyme phosphodiesterase 4 (PDE4). It targets symptoms of PsA, including skin, nails, arthritis, enthesitis, and dactylitis.

Question 61

What are the approved drugs in the IL17 inhibitor class, and what conditions do they treat?

Answer 61

Approved IL17 inhibitors include secukinumab and ixekizumab. They treat psoriasis, PsA, and ankylosing spondylitis (AS).

Question 62

What is the mechanism of action of ustekinumab, and what conditions does it treat?

Answer 62

Ustekinumab inhibits the common p40 subunit of IL12 and IL23. It is approved for the treatment of psoriasis and PsA.

Question 63

What is the mechanism of action of tofacitinib, and what conditions does it treat?

Answer 63

Tofacitinib is a JAK/STAT inhibitor. It is labeled for the treatment of psoriatic arthritis and ulcerative colitis.

Question 64

What is the mechanism of action of abatacept, and what condition is it labeled for?

Answer 64

Abatacept is an anti-T cell therapy/CTLA4 inhibitor. It is labeled for the treatment of psoriatic arthritis.

Question 65

What are the benefits and limitations of methotrexate in the treatment of PsA?

Answer 65

Methotrexate is a first-line DMARD effective for joint symptoms but has limited efficacy for enthesitis and dactylitis.

Question 66

What is the mechanism of action of secukinumab, and what conditions does it treat?

Answer 66

Secukinumab is an IL17 inhibitor. It is labeled for the treatment of psoriasis, PsA, and ankylosing spondylitis.

Question 67

What are the benefits and limitations of leflunomide in the treatment of PsA?

Answer 67

Leflunomide is effective for both psoriasis and PsA, providing mild to moderate improvements.

Question 68

What is reactive arthritis and how is it classified?

Answer 68

Reactive arthritis (ReA) is an oligoarthritis that develops 1 to 4 weeks following an enteric or urethral infection. It is classified as a type of spondyloarthritis (SpA) and is associated with conditions like PsA, AS, and inflammatory bowel disease.

Question 69

What are the common infectious agents implicated in reactive arthritis?

Answer 69

The infectious agents most commonly implicated in reactive arthritis include: - GI pathogens: Yersinia, Shigella, Salmonella, Campylobacter, Clostridium difficile - Venereal infections: Chlamydia trachomatis (urogenital infection)

Question 70

What are the clinical features of reactive arthritis?

Answer 70

The clinical features of reactive arthritis include: 1. Development of oligoarthritis (2 to 4 joints) that is asymmetric within 1 to 4 weeks after infection. 2. Predominant symptoms: - Bloody diarrhea in enteric infections. - Dysuria with purulent urethral discharge in urogenital infections. 3. The classic triad of urethral, ocular, and articular inflammation is rarely present together. 4. The condition may be self-limited or may extend beyond six months (chronic ReA).

Question 71

What are the cutaneous manifestations associated with reactive arthritis?

Answer 71

Cutaneous manifestations of reactive arthritis include: - Circinate balanitis: Develops on the shaft or glans penis, moist and generally painless. - In circumcised patients, lesions may harden to a hyperkeratotic dry crust resembling a psoriatic plaque, which can be painful and lead to scarring. - Rarely, female patients may develop erythematous vulvar ulcerative lesions.

Question 72

What is the epidemiology of reactive arthritis in relation to chlamydial infections?

Answer 72

The epidemiology of reactive arthritis shows that: - The post-venereal urogenital type typically presents in younger adults in their third to fifth decade of life, with a male predominance. - Up to 8% of patients with chlamydial infections may develop reactive arthritis. - The overall prevalence is estimated at 20 to 40 per 100,000, with a yearly incidence of 25 per 100,000.

Question 73

What is the typical time frame for the development of oligoarthritis following the triggering infection in reactive arthritis patients?

Answer 73

Oligoarthritis typically develops 1 to 4 weeks following the triggering infection.

Question 74

What is the classic triad of symptoms in reactive arthritis, and how often does it present together?

Answer 74

The classic triad of symptoms includes urethral, ocular, and articular inflammation, but it is rarely present together in the majority of patients.

Question 75

What is the male predominance in the epidemiology of post-venereal urogenital reactive arthritis?

Answer 75

The post-venereal urogenital type typically presents in younger adults in their third to fifth decade of life, with a male predominance.

Question 76

What are the cutaneous manifestations associated with reactive arthritis?

Answer 76

Cutaneous manifestations include keratoderma blenorrhagicum, circinate balanitis, aphthous ulcers, and nail changes.

Question 77

What is Keratoderma blenorrhagicum and where is it typically found?

Answer 77

Keratoderma blenorrhagicum resembles a pustular psoriasis and is generally found on the palms and soles. These skin lesions occur in 10% to 30% of cases.

Question 78

What are the characteristics of stomatitis associated with Psoriatic Arthritis?

Answer 78

A typically self-limited stomatitis may rarely develop, characterized by superficial ulcerations or erythematous grayish plaques involving the buccal mucosa, palate, and tongue. It is painless but may bleed.

Question 79

What is the typical pattern of joint involvement in Psoriatic Arthritis?

Answer 79

The typical pattern of joint involvement is an asymmetric peripheral oligoarthritis that may also involve the axial skeleton, presenting with inflammatory back and buttock pain. Oligoarthritis in the lower extremities is the most common pattern of peripheral joint involvement.

Question 80

What is enthesitis and how does it manifest in Psoriatic Arthritis?

Answer 80

Enthesitis includes inflammation of tendons, fascia, and ligaments with a predilection for insertions onto bone. It can lead to swelling and discomfort of the heel, known as Lover's heel, resulting from Achilles tendon involvement.

Question 81

What is dactylitis and what causes it in Psoriatic Arthritis?

Answer 81

Dactylitis is the result of enthesitis involving the toes and fingers, leading to a diffuse swelling.

Question 82

What is dactylitis and what causes it in Psoriatic Arthritis?

Answer 82

Dactylitis is the result of enthesitis involving the toes and fingers, leading to a diffuse swelling of the entire digit, commonly referred to as sausage digit.

Question 83

What ocular symptoms are associated with Psoriatic Arthritis?

Answer 83

Ocular symptoms include conjunctivitis and inflammatory eye diseases such as keratitis, scleritis, episcleritis, and iritis. Presenting symptoms may include photophobia and visual clouding, with potential relapse leading to chronic uveitis and visual loss.

Question 84

What cardiac complications can arise from Psoriatic Arthritis?

Answer 84

Cardiac complications can include aortic insufficiency and heart block, which may develop if there is involvement of the atrioventricular node or conducting pathway.

Question 85

What genetic factor is associated with an increased risk of Reactive Arthritis?

Answer 85

HLA-B27 is seen as a risk factor in 30% to 40% of patients with Reactive Arthritis (ReA).

Question 86

What infectious agents are commonly implicated in Reactive Arthritis?

Answer 86

Infectious agents most commonly implicated are the GI pathogens such as Yersinia, Shigella, Salmonella, Campylobacter, and C. difficile, as well as venereal urogenital infections with C. trachomatis. Other agents include Chlamydia pneumoniae, Ureaplasma urealyticum, and intravascular Bacille Calmette-Guérin.

Question 87

What are the clinical features of Keratoderma blenorrhagicum and its prevalence in cases?

Answer 87

Keratoderma blenorrhagicum resembles pustular psoriasis and is generally found on the palms and soles. These skin lesions occur in 10% to 30% of cases.

Question 88

Describe the typical pattern of joint involvement in patients with asymmetric peripheral oligoarthritis.

Answer 88

The typical pattern of joint involvement in asymmetric peripheral oligoarthritis may also involve the axial skeleton with symptoms of inflammatory back and buttock pain. The lumbar spine is more frequently involved than the cervical and thoracic spine, and oligoarthritis in the lower extremities is the most common pattern of peripheral joint involvement.

Question 89

What are the criteria for diagnosing arthritis that predominantly involves the lower limb?

Answer 89

The criteria include: 1. The arthritis should predominantly involve the lower limb, involve one or only a few joints, and not equally involve both sides of the body (asymmetric). 2. There should be evidence or a history of preceding infection, with laboratory confirmation not required if the patient has documented diarrhea or urethritis in the prior 4 weeks. 3. The patient should not have evidence that the joint itself is infected (i.e., septic arthritis), and other causes of monoarthritis or oligoarthritis should be ruled out.

Question 90

What laboratory findings are associated with the diagnosis of Reactive Arthritis?

Answer 90

Laboratory findings include: - No definitive laboratory test. - Nonspecific acute-phase reactants (e.g., erythrocyte sedimentation rate, C-reactive protein, platelet count) may be elevated. - No association with known autoantibodies such as rheumatoid factor or antinuclear antibody. - HLA-B27 haplotype can be seen in up to half of the patients who develop sacroiliitis. - Synovial fluid analysis typically shows evidence of sterile inflammation. - Cultures should be obtained for C. trachomatis in cases of urethritis and for Shigella, Salmonella, Yersinia, Campylobacter, and C. difficile for gastroenteritis.

Question 91

What imaging findings are characteristic of Reactive Arthritis?

Answer 91

Imaging findings include: - Axial imaging can demonstrate sacroiliac erosions that are frequently unilateral. - Formation of syndesmophytes where the longitudinal spinal ligaments calcify, leading to ankyloses and the development of a 'bamboo spine.'

Question 92

What are some differential diagnoses for Reactive Arthritis?

Answer 92

Differential diagnoses include: - Disseminated gonococcal infection, Lyme disease, and subacute bacterial endocarditis, which present with oligoarthritis and different skin manifestations. - Viral infections such as HIV and parvovirus B19, which present as polyarthritis. - Septic arthritis, which is generally a monoarthritis where the infectious agent can be cultured directly from the joint. - Microcrystalline diseases like gout or pseudogout, which generally present with severe monoarthritis or oligoarthritis. - Systemic lupus erythematosus and rheumatoid arthritis, which usually present with symmetric and progressive small joint polyarthritis.

Question 93

What is the initial treatment approach for acute Reactive Arthritis (ReA)?

Answer 93

The initial treatment for acute ReA involves a symptomatic approach with nonsteroidal antiinflammatory drugs (NSAIDs), as many symptoms are self-limiting.

Question 94

What role do corticosteroids play in the treatment of Reactive Arthritis?

Answer 94

Corticosteroids can be used for short-term relief of joint inflammation through intraarticular injections. They are also used topically for treating extrarheumatic features of ReA, such as inflammatory eye disease and keratoderma blenorrhagicum.

Question 95

What is the prognosis for patients with Reactive Arthritis?

Answer 95

The majority of patients with Reactive Arthritis have a self-limited course. However, relapses can occur, leading to complications such as recurrent uveitis, urethritis, or erosive arthritis.

Question 96

What is the significance of disease-modifying antirheumatic drugs in chronic Reactive Arthritis?

Answer 96

In chronic Reactive Arthritis, sulfasalazine has shown some benefit in clinical trials, while there have been no trials for methotrexate, azathioprine, and cyclosporine.

Question 97

What is the initial treatment approach for acute Reactive Arthritis (ReA) when the infectious agent is identified?

Answer 97

The initial treatment approach for acute ReA, when the infectious agent is identified, is to treat it aggressively with antibiotics.

Question 98

What role do nonsteroidal antiinflammatory drugs (NSAIDs) play in the treatment of acute Reactive Arthritis (ReA)?

Answer 98

NSAIDs are used as a symptomatic approach for initial therapy in acute ReA, as many symptoms are self-limiting.

Question 99

How are corticosteroids utilized in the management of Reactive Arthritis (ReA)?

Answer 99

Corticosteroids are used through intraarticular injections for short-term relief of joint inflammation and topically for treating extraarticular features of ReA, such as inflammatory eye disease and keratoderma.

Question 100

What is the significance of sulfasalazine in the treatment of chronic Reactive Arthritis (ReA)?

Answer 100

Sulfasalazine has been shown in clinical trials to provide marginal benefit in overall response for chronic ReA.

Question 101

A patient with chronic ReA has recurrent uveitis and erosive arthritis. What should be monitored?

Answer 101

Recurrent uveitis and erosive arthritis should be monitored in patients with chronic ReA.

Question 102

What is the significance of sulfasalazine in the treatment of chronic Reactive Arthritis (ReA)?

Answer 102

Sulfasalazine has been shown in clinical trials to provide **marginal benefit** in overall response for chronic ReA.

Question 103

What is the prognosis for patients with Reactive Arthritis (ReA)?

Answer 103

The prognosis for the majority of patients with ReA is that it has a **self-limited course**, although relapses can occur, leading to recurrent uveitis, urethritis, or erosive arthritis.

Question 104

What treatment options are available for managing recurrent uveitis and erosive arthritis in chronic ReA?

Answer 104

Treatment options include sulfasalazine for chronic ReA, corticosteroids for short-term relief of joint inflammation, and topical corticosteroids for inflammatory eye disease.

Question 105

What are the common infectious agents in urethritis for patients with ReA, and how is it managed?

Answer 105

Common infectious agents include Chlamydia trachomatis. Management involves aggressive antibiotic treatment of the inciting infectious agent.