Rheumatology: Juvenile idiopathic arthritis; HSP; Ehlers-Danlos syndrome Flashcards
What are the 5 types of juvenile idiopathic arthritis? [5]
Systemic JIA
- aka Stills disease
Polyarticular JIA
- 5+ joints
- rheumatoid factor (RF)-positive or RF-negative subtypes
Oligoarticular JIA
- 4 joints or less
Enthesitis related arthritis
- seronegative spondyloarthropathy
Juvenile psoriatic arthritis
Describe the presentation of systemic JIA (Still’s disease) [5]
Subtle salmon-pink rash
elevated serum ferritin
arthalgia
Swinging fevers
- typically rises in the late afternoon/early evening in a daily pattern and accompanies a worsening of joint symptoms and rash
lymphadenopathy
Mx for Stills?
What is a key complication of systemic JIA? [1]
What is the typical presentation of this complication? [4]
What is a key investigational finding? [1]
A key complication is macrophage activation syndrome (MAS)
- Where there is severe activation of the immune system with a massive inflammatory response.
It presents with an acutely unwell child with disseminated intravascular coagulation (DIC), anaemia, thrombocytopenia, bleeding and a non-blanching rash.
- It is life threatening. A key investigation finding is a low ESR.
TOMTIP: In children that have fevers for more than 5 days, the key non-infective differentials to remember are [4]
Kawasaki disease, Still’s disease, rheumatic fever and leukaemia.
Describe the general presentation of polyarticular JIA [2=
How do RF +ve and -ve polyarticular JIA present differently? [2]
Polyarticular JIA involves idiopathic inflammatory arthritis in 5 joints or more.
- mild fever, anaemia and reduced growth.
RF-positive polyarticular JIA
- is characterized by symmetric joint involvement, particularly in the small joints of the hands and feet.
RF-negative polyarticular JIA
- typically involves larger joints such as the knee, hip, and shoulder.
Which type of JIA is commonly associated with anterior uveitis? [1]
oligoarticular JIA
- Patients should be referred to an ophthalmologist for management and follow up of uveitis.
What is another indication that a patient has oligoarthritis JIA? [1]
Patients tend not to have any systemic symptoms and inflammatory makers will be normal or mildly elevated.
Antinuclear antibodies are often positive, however rheumatoid factor is usually negative.
Which joints are most commonly affected by enthesitis-related arthritis? [+]
Enthesitis is inflammation of this insertion point
* Interphalangeal joints in the hand
* Wrist
* Over the greater trochanter on the lateral aspect of the hip
* Quadriceps insertion at the anterior superior iliac spine
* Quadriceps and patella tendon insertion around the patella
* Base of achilles, at the calcaneus
* Metatarsal heads on the base of the foot
Describe some key clinical and investigation features of ERA? [2]
The majority of patients with enthesitis-related arthritis have the HLA B27 gene.
Patients with enthesitis-related arthritis are prone to anterior uveitis,
Medical treatment of JIA depends on the severity and response, and involves: [5]
NSAIDs, such as ibuprofen
Steroids, either oral, intramuscular or intra-artricular in oligoarthritis
Disease modifying anti-rheumatic drugs (DMARDs), such as methotrexate, sulfasalazine and leflunomide
Biologic therapy, such as the tumour necrosis factor inhibitors etanercept, infliximab and adalimumab
Describe the pathophysiology of HSP [+]
Antigenic stimulus (such as infections, drugs, or toxins) triggers IgA antibody production.
IgA antibody immune complexes deposits in vascular walls, stimulating complement activation.
Immune complex deposition causes vessel necrosis which results in organ-specific symptoms.
- Deposition in renal mesangium may result in mild proliferative to severe crescentic glomerulonephritis.
- Deposition in the gastrointestinal tract may result in abdominal pain or gastrointestinal haemorrhage.
- Deposition in the skin may result in palpable purpura and petechiae.
What is the clasic tetrad of HSP? [4]
The classical tetrad includes
* Palpable purpura
* Arthritis/arthralgia
* Abdominal pain
* Renal disease
Other Sx:
- Vary from mild (i.e., asymptomatic haematuria and/or proteinuria) to severe (i.e., rapidly progressive nephritis, nephrotic syndrome, and renal failure) renal symptoms
- Bloody stools or melena
- N&V
- Knee arthralgia
- Rash in buttocks, elbows and knee
- Rash starts as erythematous, macular, or urticarial wheals and later may coalesce and evolve into the typical ecchymoses, petechiae, and palpable purpura.
[] is the most common gastrointestinal complication of HSP
Intussusception is the most common gastrointestinal complication.
What Ix would you conduct for HSP?
Blood tests
- Coagulation studies: prothrombin time, partial thromboplastin time, and fibrinogen - Should be normal in HSP. Helps in ruling out other diagnoses such as thrombocytopenia
- Serum creatinine and electrolyte levels: ?renal failure
- Raised ESR
Urine test:
- May show hematuria, proteinuria or casts
Biopsy:
- confirmation of the diagnosis in patients with an unusual presentation (e.g., headaches, seizures, or pulmonary haemorrhage) is made via biopsy of an affected organ such as skin or kidney.
- renal biopsy: the immunofluorescence shows IgA deposition in the mesangium hence resembling IgA nephropathy.
What renal bx findings might you see in HSP? [4]
The findings may include
* Mesangial proliferation with hypercellularity
* Focal necrosis
* Segmental capillary collapse
* Epithelial crescent formation associated with more severe inflammatory damage
How do you differentiate between HSP and ITP? [2]
Idiopathic thrombocytopenic purpura (ITP)
Similarities:
- the rash of ITP also have petechiae similar to HSP.
Differences:
- arthralgias and abdominal pain are uncommon. The platelet level is low in ITP but normal in HSP.
Describe the management of HSP [+]
Treatment of pain:
- Mild to moderate JOINT pain can typically be managed with either ibuprofen or paracetamol.
- Mild to moderate ABDOMINAL pain is managed with paracetamol and supportive care.
- Oral glucocorticoid therapy is used to manage severe abdominal pain in HSP patients. If abdominal pain is accompanied by nausea and vomiting, intravenous corticosteroids may be used.
Renal involvement:
- Specific treatment with intravenous corticosteroids (pulse dosing) is recommended only in patients with nephrotic-range proteinuria and/or those with declining renal function.
- A combination of corticosteroids, immunosuppressants, and plasmapheresis is used in the patient with rapidly progressive nephritis.
- Renal transplant is reserved in patients who develop end-stage renal disease.’
What would indicate hospitalisation for HSP? [5]
- Inability to maintain adequate hydration with oral intake
- Severe abdominal pain
- Notable gastrointestinal bleeding
- Altered mental status
- Renal involvement (elevated creatinine), hypertension, and/or nephrotic syndrome
How do you monitor HSP? [1]
Patients should be followed for at least 6 months with periodic urinalysis and BP monitoring.
Define Ehler-Danlos syndrome [1]
Ehler-Danlos syndrome is an autosomal dominant connective tissue disorder that mostly affects type III collagen.
This results in the tissue being more elastic than normal leading to joint hypermobility and increased elasticity of the skin.
Describe the different types of Ehlers-Danlos syndromes [4]
Hypermobile Ehlers-Danlos syndrome
- is the most common and least severe type of Ehlers-Danlos syndrome (although it still causes significant disability and psychosocial issues).
- The key features are joint hypermobility and soft and stretchy skin.
- A single gene for hypermobile EDS has not been identified. It appears to be inherited in an autosomal dominant pattern.
Classical Ehlers-Danlos syndrome
- features remarkably stretchy skin that feels smooth and velvety.
- There is severe joint hypermobility, joint pain and abnormal wound healing.
- Lumps often develop over pressure points, such as the elbows. Patients are prone to hernias, prolapses, mitral regurgitation and aortic root dilatation. Inheritance is autosomal dominant.
Vascular Ehlers-Danlos syndrome
- is the most severe and dangerous form of EDS, where the blood vessels are particularly fragile and prone to rupture.
- Patients have characteristic thin, translucent skin. Other features include gastrointestinal perforation and spontaneous pneumothorax.
- Patients are monitored for vascular abnormalities and told to seek urgent medical attention for sudden unexplained pain or bleeding. Inheritance is autosomal dominant.
Kyphoscoliotic Ehlers-Danlos syndrome
- is characterised initially by poor muscle tone (hypotonia) as a neonate and infant, followed by kyphoscoliosis as they grow.
- There is significant joint hypermobility. Joint dislocation is common.
- Inheritance is autosomal recessive.
TOM TIP: It is worth being familiar with relatively common hypermobile Ehlers-Danlos syndrome and remembering some key features of the other types to spot them in your exams.
Which features are typical for classic EDS? [2]
Which features are typical for vascular EDS? [1]
Classical EDS:
- Extremely stretchy skin
- Severe joint hypermobilitiy
Vascular EDS:
- Thin translucent skin
- Blood vessel rupture
Hypermobile Ehlers-Danlos syndrome is associated with which pathology? [1]
Describe the symptoms [3]
Postural orthostatic tachycardia syndrome (POTS)
- Significant tachycardia occurs on sitting or standing, and symptoms include presyncope (lightheadedness), syncope (loss of consciousness), headaches, disorientation, nausea and tremor.
TOM TIP: It is worth learning and remembering to use the [] score to assess patients for hypermobility.
TOM TIP: It is worth learning and remembering to use the Beighton score to assess patients for hypermobility.
recurrent joint dislocation, easy bruising, elastic skin
A 25-year-old man is admitted following a shoulder dislocation. He has a history of joint hypermobility and is noted to have elastic, ‘stretchy’ skin on examination with multiple bruises - Ehler-Danlos syndrome
TOM TIP: Marfan syndrome is a critical differential diagnosis for hypermobility and needs to be excluded. Key features of Marfan syndrome are [4]
TOM TIP: Marfan syndrome is a critical differential diagnosis for hypermobility and needs to be excluded. Key features of Marfan syndrome are a high arch palate, arachnodactyly (long fingers) and increased arm span to body height ratio.
TOM TIP: It is worth being familiar with relatively common hypermobile Ehlers-Danlos syndrome and remembering some key features of the other types to spot them in your exams.
Remember the [2] associated with classic EDS, and the [2] with vascular EDS.
TOM TIP: It is worth being familiar with relatively common hypermobile Ehlers-Danlos syndrome and remembering some key features of the other types to spot them in your exams
. Remember the extremely stretchy skin and severe joint hypermobility associated with classic EDS, and the thin translucent skin and blood vessel rupture associated with vascular EDS.
