Diagnosis Flashcards
(43 cards)
Chronic skin ulcers (15)
- -Anthrax (eschar, lots of edema)
- -Diphtheria (gray membrane)
- -Leishmania (sand fly bite)
- -Nocardia (soil inoculation)
- -Sporotrichosis (thorny plant)
- -Diphtheria (mainly in the homeless)
- -Mycobacteria marinum or chelonae (water)
- -Mycobacteria ulcerans (often Africa)
- -Dracunculiasis (Guinea worm countries)
- -Mycetoma, such as Madurella species (mainly tropical and subtropical areas without much rainfall)
- -Rickettsial species (eschar if not RMSF)
- -Mycobacteria leprae
- -Ecthyma gangrenosum (Pseudomonas bacteremia in immunocompromised)
- -Endemic mycoses (especially with lung lesions)
- -Malignancy: SCC, BCC, mycosis fungoides, T cell lymphoma
Eosinophilic meningitis (21)
Non-infectious
Lymphoma (especially Hodgkins)
MS
Drug-induced (NSAIDs)
Helminths Angiostrongylus (nematode) Baylisascaris (nematode) Gnathostoma (nematode) Toxocara (nematode) Trichinella (nematode) Strongyloides (nematode) Loa Loa (nematode) Schistosoma (trematode) Paragonimus (trematode) Fascioliasis (trematode) Echinococcus (cestode) Neurocysticercosis (cestode)
Fungi
Coccidioidomycosis
Cryptococcus
Bacteria
TB
Syphilis
RMSF
Viruses
LCMV
Eosinophilic pnuemonia (12)
- -Paragonimiasis
- -Coccidioidomycosis
- -M. tuberculosis
- -Hodgkin’s lymphoma
- -Hypereosinophilia syndrome
- -Entamoeba histolytica
- -Ascaris lumbricoides
- -Strongyloides stercoralis
- -Ancylostoma duodenale
- -Necator americanus
- -Toxocara canis
- -Churg-Strauss syndrome
Lung abscess (16)
Anaerobic bacteria only (46%)
- -Fusobacterium necrophorum
- -Prevotella
- -Peptostreptococcus
- -Bacteroides
- -Actinomyces (facultative anaerobe)
Aerobic bacterial only (11%)
- -Staph aureus
- -Klebsiella oxytoca and pneumoniae
- -Pseudomonas
- -Strep anginosus group
- -Strep pneumoniae (rare)
Mixed infection (43%)
Other considerations if immunocompromised
- -Rhodococcus
- -Nocardia
- -Fungi
- -Mycobacteria
Non-infectious causes of similar radiography
- -Neoplasm
- -Vasculitis (like Wegener’s)
Saddle nose deformity (4)
- -Leprosy
- -Syphilis
- -Wegener’s granulomatosis
- -Relapsing polychondritis
Umbilicated rash (5)
- -Molluscum contagiosum
- -Cryptococcus
- -Varicella (primary; usually with lesions in different stages of healing)
- -Varicella (reactivation) and HSV → usually when immunosuppressed
- -Penicillium
Vasculitis and stroke (6)
- -VZV: median 4mo after zoster, no cutaneous lesions in 33%, diagnose with CSF PCR and treat with acyclovir +/- steroids
- -TB
- -Fungi
- -Sarcoid
- -Syphilis
- -Autoimmune disease (SLE, giant cell arteritis, etc.)
Vesicular rash (6)
- -HSV
- -VZV
- -Rickettsial pox (R. akari)
- -African tick bite fever (R. africae)
- -Smallpox
- -Other pox (Monkeypox)
Diagnostics for osteomyelitis and diabetic foot
Diagnosis for general osteomyelitis:
- -Plain films: usually don’t see changes until 10-14d
- -MRI: preferred; 95% sensitive, 88% specific
- -Tagged WBC scan: 88% sensitive, 85% specific
- -Bone scan: 95% sensitive, 33% specific
- -CT-guided biopsy and cx of vertebral infection is 50% sensitive
Diagnosis for diabetic foot:
- -Plain films: 54% sensitive, 68% specific
- -MRI: preferred; 90% sensitive, 79% specific
- -Tagged WBC scan: 74% sensitive, 68% specific
- -Bone scan: 81% sensitive, 28% specific
ID mimics - relapsing polychondritis: C, D
C: saddle-nose deformity, inflammation of cartilaginous structures that can be mistaken for infection depending on the location → ears (looks like cellulitis, spares the ear lobe and no regional adenopathy), nose (nasal congestion), eyes, joints (stiffness), respiratory tract
D: clinical
ID mimics - adult Still’s disease: C
C:
- -Major: fever > 39 for > 1wk; arthralgias for > 2wks; non-pruritic maculopapular rash over trunk or extremities during fevers; leukocytosis > 10,000 with > 80% granulocytes
- -Minor: sore throat; LAD; hepatomegaly and/or splenomegaly; abnormal AST, ALT, LDH; negative ANA and RF
ID mimics - Bechets disease: E, C, D, T
E: more in Asians and those of Eastern Mediterranean descent
C: recurrent aphthous oral ulcers, genital ulcers, eye or skin lesions, pathergy (red papule or pustule > 5mm at 24-48hrs after skin prick
D: recurrent aphthous oral ulcers and at least two of the above findings
T: colchicine
ID mimics - Sweet’s syndrome: E, C, D, T
E: 50% have underlying illness and 1/2 of these are malignancies (especially AML and other lymphoproliferative disorders)
C: abrupt appearance of papules or plaques (often with central yellow areas; mainly on face and extremities like the dorsum of the hands); biopsy with neutrophilic dermal infiltrates w/o vasculitis); sometimes antecedent fever, leukocytosis with bands
D: bx in right clinical context
T: steroids
ID mimics - temporal arteritis: E, C, D, T
E: elderly patients
C: fever, HA, jaw or tongue claudication, scalp tenderness, fatigue, diplopia, transient visual loss, high ESR
D: bx with granulomatous vasculitis
T: if suspecting start steroids immediately to prevent blindness (won’t affect bx for 2wks)
ID mimics - Takayasu’s arteritis: E, C, D, T
E: young women more commonly affected
C: fever, weight loss, sweats, arthralgias, myalgias, extremity claudication, visual changes, TIA/CVA, asymmetrical BP, carotid tenderness, diminished pulses
D: arteriography
T: steroids
ID mimics - Familial Mediterranean fever: E, C
E: autosomal recessive disorder often seen in Armenians, Turks, Jews, North Africans, Arabs, Greeks, Italians
C: paroxysmal fever and serositis (peritonitis, pleuritis, sometimes arthritis), can have leukocytosis
ID mimics - Kikuchi’s disease: E, C, D
E: young adults (women»>men)
C: acute onset fever, cervical LAD (most often posterior and unilateral); sometimes with arthritis, aseptic meningitis, HSM, rash, uveitis; usually normal CBC but can have leukopenia or atypical lymphocytes
D: bx of LN w/ preserved architecture with necrotizing histiocytic infiltrate (not neutrophils) and fragments of nuclear debris
ID mimics - Churg-Strauss syndrome: E, C
E: typical flare when steroids are tapered for asthma
C: allergic rhinitis, asthma, peripheral lung infiltrates, peripheral eosinophilia, skin lesions (rarely cardiac, GI, and neuropathy); p-ANCA can be positive
ID mimics - Wegener’s granulomatosis: C, D
C: upper and lower respiratory tracts (nasal sx and pulmonary nodules which can be cavitary) and kidneys (latter spared in 25%); may also involve joints, eyes, skin, CNS; rarely saddle nose
D: clinical picture w/ ANCA and supporting bx
ID mimics - anticonvulsant hypersensitivity syndrome: E, C, T
E: if taking carbamazepine, phenytoin, primidone, phenobarbital; usually 2-4wks after starting
C: fever (90-100%), rash (90%), LAD (70%), multiorgan involvement (60%), hepatitis (50%), facial edema (25%), eosinophilia (20%)
T: stop the drug and don’t start it again
Atypical bacterial pnuemomias (9)
Legionella Mycoplasma Strep pyogenes Fusobacterium Q fever Tularemia Bordatella H. flu Moraxella
Paralysis syndromes (6)
- -Guillain Barré syndrome (ascending paralysis)
- -myasthenia gravis (responds to edrophonium)
- -Eaton-Lambert (responds to edrophonium, has increased strength with repetition)
- -tick paralysis (has paresthesias)
- -inflammatory myopathy (elevated CPK)
- -botulism: descending flaccid paralysis with normal mental status, bulbar symptoms
Non infectious causes of vegetations (3)
- -acute rheumatic fever
- -Libman-Sacks endocarditis (APL Ab syndrome)
- -atrial myxoma
Hyperpyrexia syndromes (fever >41.5)
- -Malignant hyperthermia: after anesthesia, lead pipe rigidity and somnolence
- -NMS: after antipsychotics or parkinsonian drug withdrawall, rigid, agitated, autonomic instability
- -Serotonin syndrome: SSRIs, TCA, agitated, hyperreflexive, clonus, tremor, autonomic instablity
