Rheumatology Flashcards
Most common complication of uveitis associated with oligoarticular JIA?
Cataracts
Oligoarthritis or dactylitis, family history of psoriasis?
Juvenile psoriatic arthritis
- psoriasis rash may not develop for up to 10 years after joint involvement
- nail pitting is another common feature
Heel spurs are often associated with which conditions?
Plantar fasciitis and ankylosing spondylitis
What is enthesitis?
Inflammation where joint capsules, ligaments and tendons attach to bone
- is the hallmark of ankylosing spondylitis
Mechanism of action of tocilizumab?
= recombinant humanised anti-human monoclonal antibody against the IL6 receptor
Used in treatment of systemic onset JIA and polyarticular JIA
Given via infusion
Mechanism of action of infliximab?
= chimeric monoclonal antibody that binds to TNF alpha
Used in treatment of refractory Kawasaki disease
(Etanercept also binds to TNF alpha but is a recombinant protein, not shown to be effective in KD)
Mechanism of action of anakinra?
= IL1 inhibitor, administered daily
Used in the treatment of systemic JIA
Canakinumab is also an IL1 inhibitor but given monthly, and rilonacept is also an IL1 inhibitor but given weekly
Overview of hydroxychlorquine?
Anti-malarial drug, used in treatment of cutaneous rheumatological disease such as SLE and dermatomyositis
- can lead to reversible corneal toxicity
- retinal toxicity is a rare but irreversible side effect
- most common SE is nausea
- toxicity is dose related, therefore lowest effective doses are administered
6 week history of arthritis, two week history of fever, rash which is worse when febrile, lymphadenopathy and hepatosplenomegaly?
JIA
- can be very unwell initially and can be misdiagnosed with septic arthritis or osteomyelitis, but fail to respond to ABx
- should always also consider malignancy
Differences between pseudoporphyria and porphyria cutanea tarda (PCT)?
Pseudoporphyria has normal porphyrin levels in plastma/erythrocytes/urine and stool (abnormal suggests PCT)
10% of children with JIA who are taking naproxen will develop pseudoporphyria, and increased risk with pale skin/if also taking chloroquine
PCT is associated with hyperpigmentation and hypertrichosis, but pseudoporphyria is not
Skin lesions take ~6 months to heal
Ankylosing spondylitis presentation?
Usually presents with SEA syndrome
- Rh factor seronegativity
- enthesitis around foot and knee
- oligoarthritis: legs >arms (esp hips), SI joint and axial skeleton usually affected later in the course
Overview of familial mediterranean fever (FMF)?
Caused by mutations in MEFV (most are missense)
Present with 1-3 days of fever, serositis, arthritis and an erysipeloid rash (appears over ankle or dorsum of the foot is characteristic)
90% of cases present before the age of 20
Most serious complication of FMF?
Amyloidosis
- colchicine is given as prophylaxis
- usually presents with proteinuria
- if untreated, leads to renal failure in 3-5 years
What is pyoderma gangrenosum associated with?
PAPA (pyogenic sterile arthritis, pyoderma gangrenosum and acne)
Role of complement C4a and C5a?
Anaphylatoxins - promote inflammation, stimulate smooth muscle contraction, increase vascular permeability and encourage mast cell degranulation to release further inflammatory mediators
Relevance of C5a with regards to leukocytes?
Chemotactic for monocytes and neutrophils, and stimulates leukocyte adherence to blood vessel walls at the site of infection, phagocytosis and bactericidal activities
Role of IL-1 and IL-2?
Produced by macrophages and polymorphs, and have a target effect on T/B/NK cells. Interleukins are generally produced by macrophages, neutrophils, Th1 and Th2 cells. Their target effect is usually on T/B/NK cells to proliferate, differentiate and class switch
Overview of TNF alpha
TNF alpha is produced by macrophages, mast cells and NK cells, and act on macrophages and tumour cells. The main effect is to direct macrophages to produce cytokines and cause cell death
Overview of TNF beta
TNF beta is produced by Th1 cells and acts on phagocytes and tumour cells, causing phagocytosis, NO production and cell death
What is ANCA?
Antineutrophil cytoplasmic autoantibodies - directed against antigens mainly within granules of neutrophils and monocytes, whereby they cause tissue damage
Subtypes of ANCA?
Typical immunofluorescence on fixed neutrophils using serum containing proteinase 3 (PR3)-ANCA reveals a cytoplasmic pattern (C-ANCA).
Serum containing anti-myeloperoxidase (MPO)-ANCA shows a perinuclear pattern (P-ANCA)
What type of autoantibodies is microscopic polyangiitis (MPA) associated with?
Primarily associated with anti-myeloperoxidase (MPO)-ANCA
What type of autoantibodies is eosinophilic granulomatosis with polyangiitis (EGPA)/Churg-Strauss associated with?
Almost always positive for MPO-ANCA