fever and immune mediated disease Flashcards
fever vs hyperthermia
fever- raised thermoregulatory setpoint
hyperthermia- abnormalities of heat production/dissipation
causes of fever
neoplasia, infection, immune mediated disease, inflammation
define fever of unknown origin
fever lasting long enough that self limiting causes are r/o, initial diagnostics dont reveal cause, may not respond to abx
approach to working up fever
C/S, hx, PE, dx
important history questions for fever
travel hx, recent meds, hx trauma/fighting, recent heat, other animals/huamsn showing signs?
thing to look for on PE for fever workup
heart murmur, joint effusion, spinal pain, bone pain, bite wounds
renal pain, organ enlargement, rectal, masses, URT signs, lung auscultation
lymphadenopathy, 3rd spacing, oral exam, ocular exam, derm lesions
name some first tier diagnostics for fever
CBC w blood smear, chem, UA, urine culture, imaging
name some second tier diagnostics for fever
serial PE, blood culture, imaging, joint taps, 4DX, FNA, CSF, biopsy
autoimmune diseases are mediated by
Th2 cells, autoAb
- autoAb production
-opsonized cells cleared by macrophages/complement
- inflammatory cytokines
primary vs secondary immune mediated disease
primary- idiopathic, dx of exclusion
secondary- underlying cause/infection
systemic lupus erythematosus
signalment
multisystemic autoimmune disorder-> Ab against nucleus-> opsonization, immune complexes
middle aged dogs, GSD, duck toller
lupus C/S
fever, lameness, joint swelling, proteinuria (glomerulonephritis)
cutaneous- UV exposure, mucocutaneous junction
lupus diagnosis
difficult to dx, r/o underlying disorders
antinuclear antibody test (ANA)-> can have false +ve in normal animals so make sure C/S line up
LE cells-> not sensitive but specific (seen in joint fluid, blister fluid)
positive signs + ANA test, or 3+ signs w negative ANA
lupus tx and prognosis
immunosuppressives, tx IMHA, PLN
supportive care
prognosis variable, relapse possible
joint disease types (2 basic ones)
inflammatory (infectious or immune mediated)
non-inflammatory (DJD, degenerative, trauma, tumour)
septic vs sterile inflammatory joint disease?
septic- single swollen painful joint, hx trauma, current infection
sterile- multiple joints, hx of abx, vx
when to tap joint?
solitary joint disease with signs of inflammation/illness
evidence of polyarthritis
FUO
normal vs abnormal joint fluid
normal: clear, colourless, viscous
low cells <2/hpf, <10% neutrophils
abnormal: turbid/cloudy, discoloured
high cells, >20% neutrophils, bacteria
types of fluid for:
normal
sterile inflammatory
septic
degenerative/traumatic
low cells, mononuclear
high cells (>3000), non degenerative neutrophils
high cells (150000), degenerate neutrophils, bacteria
low, slightly increased, mononuclear
types of immune mediated joint disease
erosive, non erosive
erosive polyarthritis
uncommon
subchondral bone destruction, carpus affected
sm middle aged dogs
types of non erosive immune mediated polyarthritis
primary (idiopathic)-> no inciting cause, middle aged dogs most common
reactive-> infectious, medication rxn, neoplasia, dietary (uncommon)
IMPA clinical signs
lameness, stiff gait, walking on eggshells
joint pain/swelling
inappetence, lethargy, weight loss, weakness, v+, fever
polysystemic signs-> derm signs, ulcers
IMPA PE findings
fever (FUO), stiff gait, joint effusion
neck/back pain
IMPA diagnosis
joint tap- neutrophilic in mutliple joints, negative culture
check for underlying disease->CBC/chem/UA, tick borne disease testing (4DX), cultures (urine, blood), imaging
IMPA tx and monitoring
pred
monitor C/S (lameness, etc)
joint taps (1m before tapering pred)- if still inflammed add second line (cyclosporine)
