Infections Flashcards
Bacteria - other
1. DDx for eschar
2. Gram positive cocci
3. GP bacilli (rods)
4. Bacteria with branchiing filaments
5. Gram neg cocci
6. Gram neg bacilli
- Burn, anthrax, cutaneous diphtheria, tick bite, ecthyma, ecthyma gangrenosum
- GPC - Staph, Strep
- GP bacilli - Corynebacterium, Clostridium, Bacillus anthracis, Erysipelothrix
- Nocardia, Actinomyces
- Neisseria gonorrhoea, Neisseria meningitidis
- Pseudomonas, Bartonella, Burkholderia pseudomallei
Bacteria - Staph
1. Cx/serious disorders a/w Staph
2. Re impetigo
- Risk factors
- DDx non bullous impetigo
- DDx bullous impetigo
- Mgmt measures
2. Ecthyma
- who gets it
- clinical pres
- Rx
3. Staph folliculitis - mgmt
4. SSSS
- cause
- presentation
- mgmt
- compare SSSS vs TEN
5. TSS
- Risk factors
- Which staph toxin
- Which strep toxin
-Criteria
- In strep, associated with?
- Bacteraemia / sepsis, OM, septic arthritis, IE, TSS, SSSS
- Impetigo - see page
- Non B: IBR, eczema, HSV, candida, tinea
- B: bullous IBR, thermal burn, HSV, acute contact derm
- Decolonisation. Hygiene. Bleach baths. Return to school 24hr after Rx (cover sores) - see page
- ssss page
- RF: tampon use, post partum, diaphragm contraception, extremes of age. Nasal packing, surgical mesh
- TSST1
- SPE A, B, C
- 1) fever >38.9, 2) BP <90, 3) diffuse macular erythema, 4) desquamation 1-2/52 later, 5) involvement 3+ organs (GIT, MSK, renal, liver, plt, cns), 6) negative Ix for other causes (cultures)
- A/W soft tissue infection eg nec fasc
Bacteria - Strep
1. Cx/serious disorders a/w Strep
2. Invasive GAS - mgmt household contacts and why
3. Examples of iGAS infections
4. Scarlet fever
- typical presentation
- Cx
5. General strep Ix
6. Perianal/VV strep
- can you get general strep Cx?
- will also swab positive where?
- Rx?
- clinical presentation
7. Cellulitis - risk factors for recurrence
- Scarlet fever, rheumatic fever, post strep GN, guttate psoriasis. TSS. Bacteraemia / sepsis, OM, septic arthritis, IE
- rch - at risk of iGAS within 7/7. Empiric Rx - cefalex 10/7, azithro 500 5/7
3.Bacteraemia, STSS, nec fasc, pneumonia, empyema, OM, meningitis - high fever. Sandpaper like fine erythema, ‘sunburn with goosebumps’. Transverse red lines in skin folds ‘pastia lines’. Bright red tongue ‘strawberry tongue’. Resolves w desquamation
- myocarditis, hepatitis, arthritis, meningitis, OM, RF, GN
- ASOT (repeat 2/52 later), anti DNAse B. Urinalysis - RBC, casts. Throat swab
- yes can get strep Cx
- throat
- cefalex 5/7
- bright well demarcated erythema. Pain w defecation. Constipation
- Cellulitis: lymphoedema, DVT, PVD, chronic venous insufficiency, oedema, prev venectomy
Infection - other
1. Sporotrichoid spread
2. DDx widespread maculopapular rash
- Bacterial: Staph, Strep, Nocardia, Tularaemia
Fungal: Sporotrichosis, chromoblastomycosis
Typical mycobacterial: leprosy, TB
Atypical mycobacterial: M marinum
Parasitic: Leishmaniasis
Viral: cowpox - Viral - measles, rubella, EBV CMV, roseola, dengue, RRV, BFV
Bacterial - scarlet fever, TSS, secondary syphilis
Inflam - Kawasaki, GVHD, Stills
Drugs
Bacteria - other
1. Nec fasc
- types
- Risk factors
- immediate mgmt
2. IE
- Osler vs Janeway lesions
3. Clostridium
- Organisms (TBD)
- Gas gangrene. When to think about it. mgmt
4. Erythrasma
- Organism
- Woods, reason
- RF
5. Pitted keratolysis
- RF
- Wood’s fluorescence
1
- Polymicrobial, monomicrobial (GAS), marine organisms, fungal
- Diabetes, immunosuppression, cardiac or PVD, renal failure, penetrating injury, IVDU, recent surgery, preexisting ulcers
- see notes
2.
- Osler: painful papules fingers
Janeway: nontender erythematous papules palms. Can culture organism
3. Clostridium
- Tetani, Botulinum, Diphtheria
- Gas gang. Trauma, penetrating inj. Pain, swelling, d/c. Crepitus. XR - gas. Mgmt - debride. IV penicillin
4.
- C minutissimum
- Coproporphyrin III. Coral red fluoresce
- RF: obesity, humidity, hygiene, hyperhidrosis, diabetes
5.
- RF: occlusion, humidity, hyperhidrosis
- No fluoresce
Meningococcaemia
1. Microscopy appearance
2. Transmission, incubation
3. Clinical presentations
4. Cx
5. Urgent mgmt
6. Close contact mgmt
7. Vaccines
- GN diplococcus
- Respiratory. 2-10 days
- Meningococcal meningitis. Headache, neck stiff, photophob. Systemic
- Meningococcaemia. Petechiae, MP rash, purpuric lesions. Systemic Sx. Haemorrhagic bullae
- Sepsis, arthritis, DIC, pericarditis, deafness, peripheral neuropathy, MSK problems
- Hospital. Admission. LP. ABx - IV ceftriaxone 2g BD. Isolation, droplet precautions. Notifiable
- Empiric cipro 500mg stat
- 3 vax, diff serovars
Pseudomonas
1. Microscopy
2. Clinical presentations
- Gram neg rod
- Green nails. Folliculitis (hot tub folliculitis). Ecthyma gangrenosum. Pseudomonas hot foot. Otitis externa. Pseudomonas pyoderma
Bartonella
1. Organisms and their diseases
2. Tell me a bit about bartonellosis / Carrion disease
3. Tell me a bit about cat scratch disease
- B henselae -cat scratch
B quintana - trench fever
B bacilliformis - Carrion disease - Acute - Oroya fever. Systemically unwell, drop Hb from haemolysis, immunodeficiency. Recover ~10 wks
Chronic - varruga peruana. Vascular lesions, red papules and nodules. Painless - Recent bit or scratch. lNopathy can last weeks to months. May suppurate. Red papule at site
Cx: arthritis, osteolytic lesions, LNopathy, encephalopathy, pneumonia
Rx azithro
Bacillary angiomatosis
1. Organism/s
2. Who gets it
3. Clinical pres
4. Ix
5. Mgmt
- B henselae or quintana
- HIV
- Violaceous angiomatous papules and nodules
- Swab bacterial. Bartonella serology. Tissue bartonella PCR. Biopsy hhisto
- Doxy or erythro
or
azithro
Melioidosis
1. Exposure/transmission
2. Risk factors
3. Clinical pres
- how many have skin Sx
- how many present w sepsis
4. Ix/workup
5. Rx
6. Systemic sites which can be affected
- Soil, surface water. Occupational, recreational.
Wet weather - more inhalational. Military - Diabetes, immunosuppressed, male, CKD, pulmonary disease, malignancy
- Nonspecific. ‘Great mimicker’. 10-20% have skin Sx. ~50% p/w sepsis.
Skin - solitary nonhealing ulcer or inflamed skin patch - Swab. Biopsy. culture.
Ix for other involvement - BC, CXR, abdominal imaging - Initial IV 10-14/7 ceftazidime or mero then 12/52 oral eradication (bactrim). Consider surg drainage
- Pulm - pneumonia, abscess
MSK - OM, septic arthritis
CNS - encephalomyelitis
GU - renal, prostate
Non venereal treponematoses
1. Forms of disease. Brief description
2. Organism
3. does serology differentiate?
4. Rx
- Bejel: primary: papule or ulcer. Secondary: MP eruption, LNlpathy. Tertiary: gumma
Yaws: Primary - mother yaw, papule ulcerates heals w scar. Secondary - daughter yaws. Crops, near orifices. Infectious ++
Tertiary: abscesses, necrotic, ulcerate
Pinta: primary - papules/plaques at inoculation. Secondary - widespread pintids, dyspigmentation, scaly papules.
Tertiary: vitiligo like lesions - T pallidum
- No. Clinical Dx
- Azithro 30mg/kg max 2g stat
Actinomycosis
1. RF
2. Clin presentation
3. Key path features
- Dental procedures
- Lumpy jaw. Nodules, abscess. Drain ‘sulfur granules’ - clumps of bacteria
- Sulphur granules
Leprosy
1. Likelihood of acquiring infection if exposed?
2. Lepromatous leprosy - clinical features
3. Tuberculoid leprosy - clinical features
4. What would you look for O/E
5. Classification systems
6. Types of lepra reactions
7. Types of Ix
8. Pt workup Ix
9. Histopath lepromatous vs tuberculoid
10. Mgmt principles
- 5-20% (MJA)
- SMILES G CORP
- SHAG
- Sensation - pain, temperature, touch.
Neuropathic changes - muscle atrophy, vasomotor alterations, flexion contractures
Peripheral nerve enlargement
Motor power - reduced
Clinical signs above - WHO - pauci and multibacillary
Ridley Jopling - spectrum - Type 1 - reversal/upgrading. Acute neurology. Rx - pred
Type 2- ENL - type of vasculitis. Rx - thalidomide - Slit skin smear. Biopsy histo, IHC for PGL1. PCR. Serology - antiPGL Ab
Histamine; pilocarpine; lepromin - USS nerve, NCS. Nerve Bx. MRI nerve. touch testing. Sweat test
- Lepromatous: widespread infiltrate. Virchow cells - foamy macrophages. Sheets of histiocytes. ONion skin appearance of nerves.
Tuberculoid: perineural granulomas. Lymphocytic infiltrate - Multi vs pauci bacillary (12 vs 6/12)
clofazimine, rif, dapsone.
Notifiable.
F/U 5yrs, risk relapse
Cutaneous TB
1. How many infections lead to clinical disease?
2. How common is cutaneous tb?
3. Risk factors
4. True cutaneous TB:
- Endogenous (LSMOG)
- Exogenous (T/VC)
5. Tuberculids (3)
6. New pt workup
7. Path stains
8. Path features, how to differentiate from sarcoid
9. Rx
- 5-10%
- Uncommon. 8-24% cases are extrapulmonary. 1.5-3% of these are cutaneous
- HIV. Kids. Immunosuppression. diabetes, malnutrition, overcrowding
- Endogenous:
-Lupus vulgaris: most common. Red brown plaque, scale, fibrosed. Endogenous or ex.
-Scrofuloderma: contiguous spread from lN. Painless swellings, ulcers
-Miliary: unwel pts. Multiple papules, pustules, necrosis, umbilication
-Orificial: autoinoculation around orifices. Immsupp pts
-Gumma: uncommon. Fluctuating nodules
Exogenous:
- TB chancre: no prior exposure. Papulonodule -> ulcer
- TBVC: prev exposure. Verrucous plaque - Immune reactions to haematogenous dissemination of TB
EI: lobular panniculitis
Lichen scrofulosorum: numerous erythematous perifollicular papules
Papulonecrotic tuberculid:cyclic eruptions painless papules, pustules. Resolve w scarring - Palpate lNopathy. LNbx
- Lungs - cxr, ct, sputum
- Abdo - USS, CT, MRI
- Bones - XR
- Breast granulomatous mastitis
- Bloods. Biopsies - culture, AFB. PCR
Tuberculin skin test
- ZN, Fite
- Tuberculoid epithelioid granulomas, giant cells, caseation necrosis.
Sarcoid - won’t have peripheral rim lymphocytes. ZN neg - RIPE
Rif 600mg daily, Izoniaz 300mg daily, pyrazinamide 30mg/kg/day, ethambutol 15mg/kg/day for 2/12. THEN RI for 4/12
M ulcerans
1. Features suspicious for infection
2. Mgmt
- Long incubation. Painless ulcer. Deep necrotic base. Undermined edges. Solitary. can involve bone
- ID ref
Abx - rif 600mg OD + clarithro 500mg BD 8/52
Notifiable
Paradoxical worsening (stops mycolactone) - mgmt with pred
+/-: hyperbaric. Surgical
M marinum
1. Clinical
2. Incubation
3. ix
4. Mgmt
- Nodule, pustule. Solitary red to violaceous papule, nodule, plaque. Crusted ulcer
- Average 2-3/52. Can be up to 8/52
- Tissue - PCR, culture
- Clarithro 500mg BD, continue Rx 1-2/12 after resolution of lesions
Rickettsial
1. Important ones in Australia
2. General disease course
3. Complications
4. Typical histopath
5. type of organism
6. Tick paralysis - mechanism, Sx
7. Ix for Dx and Cx
8. Rx
9. How to remove a tick
10. Tell me about alpha gal
- Rickettsia australis - QLD tick typhus. Spotted fever. Ixodes holocyclus
Orientia tsutsugamushi - scrub typhus. Larval trombiculid mite
R honei - FISF - Bite -> fever in first few days. headache, myalgias, N/V, abdo pain -> D3-6 rash, MP, petechial. Eschar. LNopathy
- Pneumonitis, encephalitis, hypotension, DIC, death, renal failure, thrombocytopaenia
- Lymphocytic vasculitis, RBC extravasation
- GN rod
- Tick inject holocyclotoxins. Diplopia, lethargy, nystagmus, flulike Sx, unsteady gait. Must be attached for days for enough toxin in adults
- Paired serology and PCR from swab, Bx. Bx. Basic, ESR CRP
Cx: CXR, CT chest, MRI B. LP. USS abdomen
Convalescent serology 2-4/52 post, increase in titre 4fold - doxy 100mg BD 7/7 OR azithro 250-500mg 7/7. Ix don’t delay Rx
- see notes
- see notes
HIV
1. Examination features to support Dx of acute HIV1
2. Features of established HIV
3. Ix you would do
4. What is IRIS?
- Fever, LN, weight loss
Myalgia, arthralgia. Night sweats, pharyngitis
Morbilliform exanthem. Oral and genital ulcers. Acute retroviral syndrome resembles mono - HIV related infections
Bacterial. Viral. Fungal. Parasitic. Ectoparasites
Noninfectious (seb derm, psoriasis)
Pruritic papular eruption - Confirm Dx - HIV serology (window period, false neg, can last up to 3/12), PCR
Exclude DDx - EBV, CMV, other viral
Assoc - full sti screen - Immune reconstitution inflammatory syndrome. After starting ART - paradoxical exacerbation of infection, inflamamtory diseases, neoplasm. ~15% pts.