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Skin & MSk

Amaal Salhieh POD Professional Inglés 104 fichas

Fichas del conjunto (104)

1Cellulitis predominant causesGroup A strep and S. aureus
2Cellulitis TreatmentIf nonpurulent, Penicillinase-resistant PCN (naf and ox)
If risks of MRSA, vanc, linezolid, ceftaroline
Other options include clindamycin, TMP-SMX, doxycycline
3Erysipelas etiologyGAS
4Erysipelas TreatmentPenicillin
Macrolide as an alternative
5Furuncles & Carbuncles etiologyS. aureus
6Furuncles & Carbuncles TreatmentApply heat to facilitate drainage of pus
Antistaph antibiotic (naf, oxa), unless MRSA risks
7Impetigo etiologyGAS & S. aureus
8Impetigo TreatmentPenicillinase-resistant PCNs (naf, oxa, amoxicillin-clavulanate)
Add coverage if risks for MRSA
9Necrotizing Fasciitis EtiologyType I: Polymicrobial (usually anaerobe & GAS)
Type II: GAS
10Nec. Fasciitis TreatmentDebridement
Broad spectrum antibiotics
11Lymphangitis acuteGAS, S. aureus, Pasteurella
Use a GPS to track the cute lymph channels
12Lymphangitis ChronicFungal (sporothrix schenckil)
Mycobacterial (M. marinum)
13What is lymphadenitis?Acute or chronic inflammation of the lymph node
14What is lymphangitis?Inflammation of lymphatic channels
15Infectious arthritis etiologyS. aureus most common
Strep, gram neg possible
N. gonorrhoeae (~3%)
16Osteomyelitis most common etiologyS. aureus
17Osteomyelitis If IVDU, think..S. aureus or Pseudomonas
18Osteomyelitis If sickle cell, think..Salmonella
19Osteomyelitis If jaw, think..Actinomyces
20Osteomyelitis Mechanism of Infection_Hematogenous seeding
_Contiguous spread from adjacent infection
_Direct inoculation (trauma/surgery)
21S. aureus causes.. (under skin category)COFS
Cellulitis, Osteomyelitis, Furuncles, Septic arthritis
Staph-enie always COFS
22SSSS caused by...Exfoliative Toxin A & B from S. aureus
You better exfoliate that skin or you'll be scalded
23SSSS TreatmentNafcillin
24Nikolsky's signLight pressure to skin separates upper epidermis with wrinkling of skin
SSSS
25Group A Strep causes... (skin related conditions)LICE.N
Lymphangitis, Impetigo, Cellulitis, Erysipelas, Necrotizing Fasciitis
Strep(pers) have Nasty LICE
26M proteinGAS
Binds and stabilizes factor H to prevent complement fixation
27StreptokinaseGAS
Binds plasminogen to form plasmin
GAS with plasmin allows GAS to spread through fibrin
28Streptolysins S & OGAS
Hemolysins contribue to soft tissue damage
29SpeStreptococcal pyrogenic exotoxins
Superantigens
_Nec. Fasc, TSS, Scarlet Fever
30Scarlet FeverGAS
31GAS TreatmentPenicillins usually adequate
32C. perfringens microGram positive, spore-forming, obligatory anaerobic, bacilli
"I'm so positively perfect. Don't breath on me"
33C. perfringens PathAlpha toxin (lecithinase)
_lyses RBCs, leukocytes, endothelial cells
_tissue destruction, hemolysis, bleeding
Beta, Epsilon, lota and an enterotoxin
_Iota toxin has necrotic activity & increases vascular permeability
34Alpha toxinC. perfringens
aka lecithinase
_lyses RBCs, leukocytes, endothelial cells
_tissue destruction, hemolysis, bleeding
35Iota toxinGAS
_Iota toxin has necrotic activity & increases vascular permeability
36C. perf clinical manifestations (skin related)GM Mega Car (GMMC) are perf(ect)
Gas gangrene, Myositis, Myonecrosis, Celulitis
37C. perfringens TreatmentSurgical derbidement
Penicillin
Can try hyperbaric oxygen
38C. tetani microspore former, gram positive, anaerobic bacilli
39C. tetani PathogenesisTetanospasmin - plasmid-encoded, heat-labile neurotoxin
40TetanospasminB binds to lower
Goes to CNS via retrograde axonal transport
"A" subunit cleaves/inactivates ptns that regulate the release of GABA, so inc. in excitatory NT
-Spastic paralysis
41Lockjaw (masseter muscles) tetanustrismus
42Facial muscle contraction tetanusRisus sardonicus
My face looks like that because someone put Reeses on Sardines
43Back spasms tetanusOpisthotonos
"(O)h, my back. It feels like I (pis)sed tho ton(os)"
44C. tetani TreatmentSurgical debridement
Penicillin or metronidazole
Tetanus Ig
Vaccination
45C. tetani vaccineToxoid
46P. aeruginosa PathETA
Pyocyanin
Pyoverdin
LasA & LasB
47LasA and LasBproteases
degrade eLAStin
48Pyocyaninproduction of superoxide and H2O2
49Pyoverdinsiderophore
50Pseudomonas Clinical ManifestationsO PUBEES
(PseudoMONA was naked and you could see her PUBEES)
Osteochondritis, Pneumonia, UTI, Bacteremia, Ecthyma gangrenosum, Ear infections, Skin infections
51Pseudomonas Skin InfectionsBurn wounds
_vascular damage, tissue necrosis, bacteremia
Folliculitis
Ecthyma gangrenosum
52Vibrio microComma-shaped gram negative rods
Oxidase/catalase +
Grow in salt & TCBS
53V. vulnificusLiver disease patients in particular
- Infections of wounds contaminated by salt water
• Progressive & severe wound infections
• Vesicles form followed by necrosis
- Also gastroenteritis after shellfish
54V. parahemolyticus- Primarily gastroenteritis after shellfish/oysters
- Occasionally wound infections
55Pasteurella multocida microGram neg. coccobacilli
Grow on blood/choc, not MAC
56Pasteurella multocida TreatmentPenicillin
57Capnocytophaga microFilamentous, gram neg rods
Grows on blood/choc, not MAC
Requires higher CO2
58Capnocytophaga TreatmentAmoxicillin-clavulanate
59M. marinum from...wound suffered/contaminated in water
60M. marinum clinical manifestationsPapules on extremity
Ulcerate and form scare
"Fish tank granuloma"
Can have nodular lymphangitis (Sporotrichoid spread)
61Mycobacterium leprae Good CMITuberculoid leprosy (paucibacillary)
62Mycobacterium leprae Poor CMILepromatous leprosy (multibacillary)
63Tuberculoid leprosy- Localized hypopigmented or erythematous skin lesions
- May have nerve involvement with palpable nerves
• Sensory loss
Low infectivity
64Lepromatous leprosy- Numerous erythematous lesions of skin
- Diffuse nerve involvement with patchy sensory loss
- Tissue destruction (often of face/ears)
- Leonine facies & saddle nose
- Infectivity is high
65Tuberculoid leprosy Treatment• Dapsone & Rifampin x6-12 months
66- Lepromatous leprosy Treatment• Dapsone, Rifampin & Clofazimine x2 years
67- Dapsone• Interferes with folic acid synthesis (PABA antagonist)
68- Clofazimine• Binds to guanine bases in DNA
• May cause hyperpigmentation & phototoxicity
69Malassezia furfur MicroRequires olive oil (FAs) to grow
Can grown on blood agar or fungal agars (potato dextrose agar) with olive oil
70Potato dextrose agarMalassezia furfur
71—Malassezia furfur
72—Malassezia furfur
"Spaghetti and meatballs"
73Malassezia furfur Clinical Man.Tinea (Pityriasis) Versicolor
_Hypo/Hyperpigmented macules on upper body usually
Asymptomatic otherwise – rare pruritis
Occasionally TPN (Total Parenteral Nutrition)-related sepsis
_Lipids in TPN promote growth of yeast
74Malassezia furfur TreatmentTopical azoles
Selenium sulfide
75—Malassezia furfur
76—Malassezia furfur
77Dermatophytes Treatment for localized and not affecting hair or nailsTopical (azoles, terbinafine)
78Dermatophytes Treatment affecting hng hair, nails, groin or diffuseOral agents (griseofulvin, terbinafine, azoles)
Hair is full of grease (griseofulvin)
79—Dermatophyte
Tinea barbae
80—Dermatophyte
onychomycosis (Tinea unguium)
81—Dermatophyte
Tinea corporis
82Dermatophytes invade..skin, hair & nails – keratinophilic & keratinolytic
Primarily involve stratum corneum
83—Dermatophytes
H&E biopsy
84—Sporothrix schenckii
85—Sporothrix schenckii
(Donald Trump size hands)
86Sporothrix schenckii MicroDimorphic fungus
Ubiquitous in soil & vegetation
Daisy/floret-like conidia as mold in culture at 25ºC
Cigar-shaped (and oval) yeasts in tissue
87Sporothrix schenckii Clinical Man.“Rose-gardener’s disease”
Nodule at site of inoculation (+/- ulceration)
Nodules form along lymphatic channels ~2 weeks later
88If you see "Sporotrichoid spread", think...S. schenckii,
M. marinum, & Nocardia
89Sporothrix schenckii TreatmentPotassium iodide
Itraconazole often used instead
90—Ancylostoma braziliense
91—Ancylostoma braziliense
92Ancylostoma braziliense EpidemiologyWidespread
Often children in contact with feces-contaminated soil/sand
Larvae penetrate intact skin
93Ancylostoma braziliense Clinical Man.Pruritis
Erythematous or vesicular reaction to serpentine tunnels
94Ancylostoma braziliense TreatmentAlbendazole or Ivermactin
95Dracunculus medinensis Epidem.Isolated areas in Africa
96Dracunculus medinensis Transmission & Life Cycle*Larvae in water infect small crustaceans
*Ingestion of unfiltered water may contain crustaceans
*Larvae released in stomach & small bowel
*Get into abdominal cavity & retroperitoneum where they mate
*Males die, females move to subcutis & release larvae
*Forms blister on skin which ruptures
97Dracunculus medinensis Clinical Man.Painful ulcer with emergence of worm
Gross...
98Dracunculus medinensis TreatmentRemove the worm. Duh.
99—- Dracunculus medinensis
100Trichinella spiralis Epidem.Worldwide, including US
Associated with pork consumption (haram!)
101Trichinella spiralis Life Cycle*Pigs contain adult worms & encysted larvae
*Humans ingest encysted larvae in undercooked meat
*Larvae develop into adults in small intestine
*After mating, females release larvae
*The released larvae get into blood stream and lodge in muscle
*Can get cardiac, CNS, lung involvement
102Trichinella spiralis Clinical Man.Periorbital & facial edema, conjunctivitis
Fevers, myalgias & weakness
Rarely myocarditis, CNS involvement & pneumonitis
Eosinophilia
103Trichinella spiralis TreatmentAlbendazole
104—Trichinella Spiralis