Psoriatic arthritis and reactive arthritis Flashcards
What is psoriatic arthritis?
Psoriatic arthritis is an inflammatory arthritis affecting the joints and connective tissue and is associated with psoriasis of the skin or nails.
Occasionally psoriatic arthritis may occur in the absence of skin disease, or there may only be an insignificant rash which may not be noticed.
Psoriatic arthritis may involve not only the joints in the sense of arthritis but also the tendons surrounding the joints, leading to swelling of whole digits (dactylitis), or it may lead to inflammation of the entheses (enthesitis)
Affect 5-25% of people with psoriasis
What are the risk factors for PA?
Psoriatic arthropathy is much more common in the western white population than in other races.
Men are more commonly affected by the spondylitic subtype, with higher incidence of the ‘rheumatoid’ pattern of disease among women.
It is most common in middle age (35-55) but may be seen in patients of any age.
What is the presentation of PA?
An annual assessment for psoriatic arthritis should be offered to people with any type of psoriasis.
The characteristics of psoriatic arthritis include joint stiffness, pain and swelling, and tenderness of the joints and surrounding ligaments and tendons. Symptoms can range from mild to very severe. The arthritis tends to be relapsing and remitting.
Usually the rash precedes the arthritis by a few years but the opposite is occasionally true.
The condition can present in those with minimal or no obvious rash. Occult rash should be looked for on the scalp, on extensor aspects of the forearms/elbows and in the umbilicus and natal cleft.
Some patients will only have nail changes rather than rash. Nails may show pitting, yellowing, transverse ridges or destruction (onycholysis).
Enthesopathy affecting the Achilles tendon and plantar fascia is frequently seen. Tenosynovitis tends to affect the flexor rather than extensor tendons (both commonly affected in rheumatoid arthritis).
Ocular involvement may be seen with conjunctivitis (20-30% of cases) and anterior uveitis (5% or so). Sacroiliitis and HLA-B27 positivity are commonly associated with ocular disease.
Rarely aortitis, similar to that seen in ankylosing spondylitis or reactive arthritis, and secondary amyloidosis are features of the disease.
What are the differentials of PA?
RA Reactive arthritis Ankylosing spondylitis Enteropathic arthropathy Gout Septic arthritis Juvenile idiopathic arthritis
What are the investigations for PA?
ESR and/or CRP will often be elevated.
It is not unusual for serum urate to be elevated in the acute phase and gout may co-exist with psoriatic arthritis.
Synovial fluid aspirate should not show evidence of any crystals; however, the white cell count (predominantly neutrophils) is often significantly high.
Serum immunoglobulin A (IgA) is elevated in about two thirds of sufferers
X-ray changes classically associated with psoriatic arthritis include:
MRI/CT scan
What are the X-ray changes seen in PA?
Mild bony erosion at the edge of cartilage.
Asymmetric erosive changes in the small joints of the hands and feet.
DIP or proximal interphalangeal (PIP) involvement - more common than metatarsophalangeal (MTP) or MCP changes.
DIP cases may have erosion and deformity with bony ankylosis of the joint and subluxation.
Erosion of the distal tuft of the distal phalanx.
What is the management of PA?
Referral to a rheumatologist.
In patients with psoriasis and psoriatic arthritis, monotherapy that addresses both skin and joint disease should be used in preference to multiple therapies.
Methotrexate, retinoids and psoralen combined with ultraviolet A (PUVA) treatment appear to be most effective at treating skin and joints together.
In patients with psoriatic arthritis, non-steroidal anti-inflammatory drugs (NSAIDs) may be used to relieve musculoskeletal symptoms.
Local injections of corticosteroids should be considered as adjunctive therapy in psoriatic arthritis
DMARDs:
- Leflunomide is recommended for the treatment of active peripheral psoriatic arthritis.
- Sulfasalazine may be considered as an alternative in the treatment of peripheral psoriatic arthritis.
- Methotrexate may be considered in the treatment of psoriatic arthritis, especially when associated with significant cutaneous psoriasis.
- Antimalarial derived DMARDs such as hydroxychloroquine are usually avoided, as they may cause exfoliative dermatitis, worsening psoriasis.
Biologics
-TNF inhibitors (adalimumab, etanercept, golimumab and infliximab) should be considered:
In patients with active arthritis and an inadequate response to at least one synthetic DMARD, such as methotrexate.
In patients with active enthesitis and/or dactylitis and insufficient response to NSAIDs or local steroid injections.
Surgery to treat deformed joints.
Physical exercise to maintain mobility and reduce stiffness.
What are the complications of PA?
These include joint destruction, finger destruction, disability, extra-articular complications such as eye disease and, rarely, aortitis (causes aortic insufficiency).
Psoriatic arthritis can affect people’s ability to work and carry out daily activities, which can have a substantial impact on quality of life.
Atlanto-axial subluxation with attendant neurological complications can occur.
Psoriatic arthritis is associated with an increased risk of cardiovascular disease
What is reactive arthritis?
Reactive arthritis is a form of seronegative spondyloarthritis clinically associated with inflammatory back pain, additive or migratory oligoarthritis and extra-articular symptoms that typically follow a gastrointestinal or urogenital infection by a minimum of 1 to a maximum of 3-6 weeks.
What is reiter’s syndrome?
The presence of large joint oligoarthritis, urogenital tract infection and uveitis characterises a syndrome (formerly named after the doctor who first described it as a clinical subtype of reactive arthritis).
What is the classification of reactive arthritis?
There appears to be a strong association with HLA B27 (~75%) and the seronegative arthropathies.
The syndrome is sometimes subdivided into two subgroups:
- Post-enteric: the three most commonly associated enteric pathogens are Campylobacter, Salmonella and Shigella species.
- Post-venereal: following Chlamydia trachomatis infection or with human immunodeficiency virus (HIV).
What is the presentation of reactive arthritis?
Reactive arthritis usually develops 2-4 weeks after a genitourinary or gastrointestinal infection. About 10% of patients do not have a preceding symptomatic infection.
The onset is most often acute, with malaise, fatigue, and fever.
An asymmetrical, predominantly lower extremity, oligoarthritis (usually no more than six joints) is the major presenting symptom.
Low back pain often occurs.
Heel pain is common because of inflammation of the Achilles or plantar aponeurosis insertions on the calcaneus.
The complete triad of urethritis, conjunctivitis, and arthritis may occur.
Skin (eg, erythema nodosum, circinate balanitis), nails (dystrophic changes) and mucous membranes (mouth ulcers) may all be affected.
Other features include:
- Eyes: uveitis, episcleritis, keratitis, and corneal ulcerations.
- Gastrointestinal: some patients have intermittent bouts of abdominal pain and diarrhoea - and show lesions on colonoscopy, similar in appearance to inflammatory bowel disease.
- Cardiovascular: aortitis with or without aortic regurgitation (2%), conduction defects.
What are the differentials for reactive arthritis?
Ankylosing spondylitis and undifferentiated spondyloarthropathy. Gonococcal arthritis. Gout. Inflammatory bowel disease. Psoriatic arthritis. Rheumatic fever. Rheumatoid arthritis. Septic arthritis.
What are the investigations for reactive arthritis?
Once arthritis is observed, microbial tests and blood or synovial fluid cultures are negative, and only serum antibodies are detected.
ESR and CRP are usually very high.
FBC: normocytic normochromic anaemia, mild leukocytosis and thrombocytosis during the acute phase.
HLA-B27 is positive in the majority of those affected. Rheumatoid factor and antinuclear antibodies are absent.
Joint aspiration may be required to rule out septic or crystalline arthritis. Synovial fluid analysis in patients with reactive arthritis shows a high white blood cell count (mostly polymorphonuclear leukocytes in acute phase).
Culture of stools, throat and urogenital tract samples in order to identify the causative organism.
Serology for detection of chlamydia - eg, polymerase chain reaction (PCR). Refer to a sexual health clinic for further genitourinary investigation in sexually active patients.
Serology for other possible infectious triggers - eg, Yersinia, Campylobacter, Salmonella and Shigella species.
X-rays: normal in early stages of disease. In advanced or long-term disease, they may show periosteal reaction and proliferation at sites of tendon insertion, plantar spurs, marginal erosions with adjacent bone proliferation in the hands and feet and, less often, features of sacroiliitis and ankylosing spondylitis.
ECG: in patients with prolonged disease to assess for conduction disturbances.
What is the management of reactive arthritis?
In the acute phase, rest affected joints, aspirate synovial effusions.
Physiotherapy.
Non-steroidal anti-inflammatory drugs (NSAIDs).
Corticosteroids:
-These can be used as either intra-articular injections or systemic therapy. Joint injections can help avoid the use of other systemic therapy. Sacroiliac joints can be injected, usually under fluoroscopic guidance.
-Systemic corticosteroids can be used (particularly in patients unresponsive to NSAIDs or who develop adverse effects).
Antibiotics to treat an identified causative organism. Antibiotic treatment does not change the course of reactive arthritis, even when an infective cause is identified.
