Masquerades/Mimics Flashcards
MC rheum cause of FUO
giant cell arteritis (large vessel arteritis)
most specific test for SLE
anti-smith Ab
(anti dsDNA also quite specific)
(ANA very sensitive, but not specific)
anti-Ro/SSA
anti-La/SSB
Sjogren
c-ANCA
GPA
p-ANCA (antimeyloperoxidase)
eosinophilic granulomatosis w/ polyangiitis
fever
arthralgia/myalgia
extremity claudication
weak pulses
discrepant BP
takayasu (large vessel)
F, peripheral neuropathy, A/M, abd pn
cutaneous disease: nodules, ulcers, palpable purpura
multiorgan ischemia: look for GI, renal, and CNS (stroke-like) presentation
mimics IE w/ septic embolization
multiple aneurysms
polyarteritis nodosa (medium-vessel)
palpable purpura in LEs (any pressure or gravity-dep area)
arthritis/arthralgia
recurrent abd pain (can be severe)
glomerulonephritis
testicular pain (mimics epididymitis)
consider IgA vasculitis (formerly Henoch-Schonlein purpura)
recurrent F (lasts 1-3 days)
+
serositis (signs of peritonitis and pleuritis)
+
erysipelas-like erythema on legs
think of FMF
recurrent F (lasts >7 days)
migratory rash
eye involvement common (periorbital edema, conjunctivitis)
think TRAPS
elevated IgD (often IgA as well)
recurrent F (lasts 3-7 days)
usually presents 1st yr of life
triggered by vaccines
HyperIgG Syndrome (HIDS)
brief episodes of fever, conjunctivitis, and urticarial rash after cold exposure
cryopyrin-associated periodic syndrome (CAPS)
fever w/ aphthous ulcers, pharyngitis, and adenitis
3-6 days every 3-4wks like clockwork
PFAPA
50yo
daily fevers
chronic urticarial rash, skeletal hyperostosis, LAD
Schnitzler’s syndrome
F + cervical LAD in young (usually Asian) female
think Kikuchi’s disease
DX: bx w/ necrosis and significant histiocytic inflammation
TX: steroids
Non-infectious causes of pathergy
sweet’s syndrome
pyoderma gangrenosum
Behcet syndrome
(ALL demonstrate neutrophilic dermatosis on skin bx)
Indolent, fever rare
Papule at site of trivial trauma –> painful ulcer w/ violaceous/red border and necrotic base
dx? and what assoc syndromes?
pyoderma ganrenosum
- IBD MC
- also inflammatory arthritis
- solid organ/heme malignancy
- recurrent cellulitis (cartilage inflammation - not true cellulitis)
- saddle-nose
- cauliflower ear
- sparing of ear lobe
- parasternal joint involvement
buzz words for relapsing polychondritis
- evanescent, salmon-colored rash
- multi-system illness
- elevated ferritin
- pharyngitis
- Koebner (rash elicited by stroking skin/areas of pressure)
Adult Still’s buzz words
- acute onset
- always febrile
- neutrophilic dermatosis
- Esp in setting of malignancy (AML), IBD, recent URI, vaccination, pregnancy
Sweet syndrome buzz words
- self-limited fever + cervical LAD (esp unilateral/posterior)
- morbiliform exantham
- variably leukopenic with atypical lymphocytes
LN bx: necrotizing histiocytic infiltrate (not neutrophils)
consider kikuchi disease
young women w/o racial/ethnic proclivity
- morning stiffness in proximal muscles (shoulder and hip)
- difficulty initiating movement after prolonged immobility
buzzwords for PMR
Infections a/w HLH
- EBV (other herpesviridae)
- HIV
- histo
- Ehrlichia
triad: hilar LAD, acute arthritis (ankles MC), erythema nodosum
Lofgren sydnrome (Sarcoid)
***uveitis, aseptic meningitis w/ basilar enhancement, non-caseating granulomas
Presentations of Behcets
mucosal ulcers on mouth/genitals
+
GI (vs CMV)
Aseptic meningitis (vs HSV)
Visual changes
Pathergy (needle/IV site)
Minor Criteria for Still’s
- sore throat
- LAD
- HM/SM
- abnormal LFTs
- negative ANA/RF
pustule at site of venipuncture
Behcets
HLH clues
- EBV (or other infection with progressive sx)
- massively elevated ferritin
- cytopenia with negative ID w/u
periodic episodes of fevers + serositis PLUS
colchicine responsiveness
mediterranean ethnicity
FMF buzz words
Causes of EN
“NODOSUM”
- NO cause >50%
- Drugs: sulfonamides, PCNs
- Oral contraceptives
- Sarcoid (Lofgren’s syndrome)
- Ulcerative colitis (or Crohn’s or Behcets)
- Microbes (EBV, HBV/HCV, strep, bartonella, TB, endemic fungi)
Major criteria for Still’s
- Fever >39C for 1+ week
- Arthritis/arthralgia >2wk
- typical rash (during fevers) - salmon-evanescent
- WBC >10k (>80% PMNs)
syndromes a/w saddle-nose deformity
- Relapsing polychondritis
- Lepromatous leprosy
- Congenital syphilis
- Leishmaniasis
- GPA
- Cocaine use
young woman (asian ancestry)
carotidynia (pn w/ palpation)
decreased pulses
extremity claudication
visual changes
TIA
Takayasu arteritis
dx via arteriography
longstanding asthma
new infiltrates and eosinophilia as steroids tapered
rash (tender nodules on extensor surfaces, purpura, ecchymosis, necrosis)
fever uncommon
buzz words for Churg-Strauss
