Chapter 16 - Rheumatology Flashcards
1
Q
Henoch-Schonlein Purpura
A
- an IgA-mediated vasculitis affecting the skin, joints, GI tract, and kidneys
- typically presents following a viral syndrome
- features include an erythematous maculopapular rash which progresses to petechiae and palpable purpuric lesions concentrated on the buttocks and lower extremities; arthrlagias or arthritis most often affecting the knees and ankles; colicky abdominal pain, GI bleeding, and risk for intussusception; and nephritis syndrome
- labs may find elevated serum IgA; platelet count is normal despite petechiae and purpura; get a UA and BUN/creatinine to evaluate renal involvement
- treatment involves steroids and supportive care; most patients recover in 4 weeks
2
Q
Kawasaki Disease
A
- an acute, febrile vasculitis of childhood
- most commonly presents in males, younger than 5 years old, of Asian ethnicity
- diagnosis is based on fever lasting more than five days plus four of the following: bilateral conjunctivitis; oropharyngeal changes such as red, cracked, swollen lips; cervical adenopathy, which is typically unilateral and nonsuppurative; a rash affecting the trunk; and changes in the distal extremities including edema, erythema, or peeling around the nail beds
- other features may include coronary aneurysms, urethritis, aseptic meningitis, hydrops of the gallbladder with RUQ pain, or anterior uveitis
- the course is triphasic: the acute phase lasts 1-2 weeks with most of the symptoms beginning and ESR/CRP elevated; the subacute phase then lasts weeks to months during which the distal extremity changes usually occur and coronary artery aneurysms occur if they are going to while ESR and CRP decline and platelet count rises; the convalescent phase which takes weeks to years with gradual resolution of aneurysms and normalization of all findings
- during the acute phase, high-dose IVIG is used in conjunction with high dose aspirin to prevent aneurysms and limit inflammation, respectively; in the subacute phase, low dose aspirin is used for its anti platelet effect and can be continued through the convalescent phase only if aneurysms remain; steroids are contraindicated in all phases
3
Q
Juvenile Rheumatoid Arthritis
A
- chronic joint inflammation in children with or without extra-articular involvement
- diagnostic criteria include younger than 16 years old and arthritis in one or more joints lasting longer than 6 weeks
- typically presents in females but males are more likely affected by the systemic and late-onset pauciarticular subtypes
- classification is based on the clinical features during the first 6 months of the disease as either pauciarticular, polyarticular, or systemic
- labs are nonspecific but typically demonstrate microcytic anemia (of chronic disease) and elevated ESR and CRP; the presence of rheumatoid factor and ANA depend on the subtype
- should be managed with NSAIDs, stronger immunomodulatory medications for severe symptoms, physical and occupational therapy, selective splinting to minimize joint contractures, and pscyhosocial support
4
Q
Pauciarticular Juvenile Rheumatoid Arthritis
A
- juvenile arthritis affecting four or fewer joints
- the early-onset subtype affects predominantly females between 1-5 years old; usually spares the hips and sacroiliac joints; patients are at high risk for developing chronic uveitis and must be monitored with regular slit-lamp evaluations; ANA is typically positive as are ESR and CRP
- the late-onset subtype affects predominately males older than 8 years old who are HLA-B27 positive; it typically does involve the hips and sacroiliac joints; and it carries a risk of spondyloarthropathy
5
Q
Polyarticular Juvenile Rheumatoid Arthritis
A
- juvenile arthritis affecting more than four joints, typically without or with only mild extra-articular features
- subclassified based on the presence of rheumatoid factor: RF-negative disease presents both early and late in childhood while RF-positive disease presents in those older than 8 years and tends to be more severe
- the joint involvement affects both large and small joints; children may suffer from deforming arthritis
6
Q
Systemic-Onset Juvenile Rheumatoid Arthritis
A
- juvenile arthritis with severe systemic symptoms
- these may include high spiking fevers, most commonly in the late afternoon or evening; transient, non-pruritic, salmon-colored rash on the trunk and proximal extremities; hepatosplenomegaly; lymphadenopathy; and constitutional symptoms, serositis, CNS involvement, and myositis
- males and females are equally affected
- 50% of patients recover completely while the other half develop chronic destructive arthritis
7
Q
Systemic Lupus Erythematosus
A
- an immune complex-mediated vasculitis
- typically presents in adolescence
- features include constitutional symptoms, CNS involvement, malarkey rash, photosensitivity, alopecia, Raynaud’s phenomenon, arthritis and arthralgia, libman-sacks endocarditis, pericarditis, pleuritic, diffuse proliferative glomerulonephritis, anemia, and thrombocytopenia
- neonates born to mothers with SLE may have congenital heart block due to the activity of anti-SSA antibodies which cross the placenta
- ANA is a sensitive but non-specific marker; anti-dsDNA is more specific and can be used as a marker for disease activity; anti-Sm is also specific but cannot be used as a marker for disease activity
- antiphospholipid antibodies which increase the risk for thrombotic events may also be presents and there may be diminished levels of complement
- treated with NSAIDs, glucocorticoids, and stronger immunomodulators; anticoagulation may be needed for those with antiphospholipid antibodies; manage renal complications to prevent failure and fluid/electrolyte imbalances
- major causes of mortality are infection, renal complications, or CNS involvement
8
Q
What are the classic findings of SLE?
A
- non-specific: fever, weight loss, Raynaud phenomenon
- malar or discoid rash, especially upon exposure to sunlight
- painless nasopharyngeal ulcers
- arthritis
- serositis
- psychosis
- renal damage (diffuse proliferative glomerulonephritis is the most common nephritic syndrome, membranous glomerulonephritis the most common nephrotic syndrome)
- anemia, thrombocytopenia
- Libman-Sacks endocarditis (small vegetations on both sides of the mitral valve)
- ANA (sensitive but not specific)
- anti-dsDNA (specific, indicates poor prognosis) or anti-Sm antibodies (specific, not an indicator of prognosis)
9
Q
Dermatomyositis
A
- an inflammatory disorder of the skin and skeletal muscle
- most often affects females 5-14 years of age
- presents with constitutional symptoms, bilateral proximal muscle weakness (positive Gower’s sign) as well as three types of rash: affecting the upper eyelids (heliotrope), malar rash, and red papules on the elbows, knuckles, and knees known as Gottron papules; other symptoms may include calcinosis, constipation, dysphagia, or cardiac involvement
- may be complicated by aspiration pneumonia, intestinal perforation, and osteopenia
- labs find positive ANA and elevated creatine kinase but most important is anti-Jo-1 antibody; also anti-SRP and anti-Mi-2 antibodies
- histology demonstrates perimysial inflammation (CD4) with perifascicular muscle fiber atrophy
- treat with corticosteroids followed by long-term immunosuppression like methotrexate; supplement vitamin D and calcium to repair osteopenia
- unlike with adults, there is no associated malignancy
10
Q
Rheumatic Fever
A
- a systemic complication of pharyngitis due to a group A B-hemolytic strep (increase in anti-Streptolysin O titers)
- due to molecular mimicry of the bacterial M protein (type II hypersensitivity)
- arises 2-3 weeks after an episode of strep throat
- presents with migratory polyarthritis (migratory swelling and pain in large joints), pancarditis, subcutaneous nodules, erythema marginatum (annular, nonpuritis rash with erythematous borders), and sydenham chorea (rapid, involuntary muscle movements) - the so-called “JONES criteria” (joints, heart, nodules, erythema marginatum, and sydenham chorea)
- endocarditis affects the mitral valve more than the aortic with small vegetations along the lines of closure leading to regurgitation
- myocarditis with Aschoff bodies (foci of chronic inflammation, reactive histiocytes with slender, wavy nuclei called Anitschkow cells, giant cells, and fibrinoid material)
- pericarditis presents with friction rub and chest pain
- myocarditis is the most common cause of death in the acute phase
- treat with penicillin to eradicate strep infection; use NSAIDs or corticosteroids to control the inflammation and haloperidol for severe sydenham’s chorea
- usually resolves, but repeat exposure to group A B-hemolytic strep results in relapse of the acute phase and increase the risk of progression to chronic rheumatic heart disease
11
Q
Describe the cardiac features of acute rheumatic fever.
A
there is a pancarditis, but myocarditis is the most common cause of death in the acute phase
- endocarditis preferentially affects the mitral valve over the aortic valve and small vegetations along the closure lines lead to regurgitation
- there is a distinct myocarditis with Aschoff bodies characterized by foci of chronic inflammation, Anitschokow cells (reactive histiocytes with slender, wavy nuclei), giant cells, and fibrinoid material
- pericarditis presents with a friction rub and chest pain
12
Q
What mechanism serves to bring about acute rheumatic fever?
A
molecular mimicry between the bacterial M protein of group A beta-hemolytic strep and human tissue
13
Q
Lyme Disease
A
- caused by a spirochetal infection with Borrelia burgdorferi, transmitted by the Ixodes tick bite if attached for more than 36-48 hours
- most prevalent in the New England states
- early localized disease presents with erythema migrans, a target-like rash, which may be asymptomatic, pruritic, or painful, and constitutional symptoms of fever, headache, myalgia, etc.
- early disseminated disease is characterized by facial nerve palsy and heart block; late disseminated disease is characterized by arthritis
- ELISA is a highly sensitive screening test that should be confirmed with western blot
- treat with doxycycline for children over 9 or amoxicillin if younger; may require ceftriaxone or penicillin if there is carditis or meningitis
14
Q
What features are shared by seronegative spondyloarthropathies?
A
- involves joints of the axial skeleton
- absent rheumatoid factor, ANA, or other disease-specific serologic marker
- association with HLA-B27
15
Q
What is reactive arthritis?
A
a seronegative spondyloarthropathy characterized by arthritis, urethritis, and conjunctivitis, usually triggered by C. trachomatis infection
