Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

microbiology year 2 > skin infections > Flashcards

skin infections Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

epidemiology of skin disease

A

15% of GP consultations are skin related

6% of hospital out patient attendances are skin related

In Europe

  • 1% of population is referred to a dermatologist per year
  • 20% of population have a skin disease requiring medical intervention
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

epidemiology of skin infections *

A

High rates in hot humid conditions and poor populations

Low rates in dry temperate conditions and rich populations

in uk:

  • 25% of GP skin consultations
  • 5% of dermatologist consultations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

describe staphylococcus aures *

A

bacteria

gram +ve - purple on gram stain

makes toxins

has a capsule (AB destroy this capsule)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are medical considerations for staph aures *

A

it is commensal on body in nose armpit and groin

most common cause of skin infections

MRSA - no more severe form, just harder to treat because it is resistant to flucloxacillin

causes bone joint and jung infections - especially after flu - causes pneumonia

can cause sepsis

makes toxins

  • Panton Valentine Leuocidin (PVL)
    • virulence factor
    • means more agressive form - necrotising soft tissue infection, inflammatory, form absess
  • Exfoliative toxin
    • cleavage and blister formation in skin
  • TSST-1 (Toxic Shock Syndrome Toxin 1)
    • more toxic - septicaemia features
  • Enterotoxin
    • cause diarrhoea if contaminates food
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

describe the manifestations of s aures skin infection *

A

impetigo - infection of the subcorenal layer of the epidermis

folliculitis - infection of the mouth of hair follicle

ecthyma - infection and necrosis of full thickness of the epidermis

boil - abscess of hair follicle (ie a folliculitis with pus)

carbuncle - abcess of several adjacent hair follicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

describe impetigo *

A

staph aures

honey coloured crusting erosion

crusty

common in children around the nose and mouth, easily transmitted

can get impigotised eczema - ie s. aures on top of eczema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

describe bullous impetigo *

A

staph aures

expholiated toxin cause split of skin at higher levels of the epidermis = bulli formation

in the bulli are bacteria that are producing pus

(same enterotoxin will cause blisters all over in Staphylococcal scalded skin syndrome)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

describe ecthyma *

A

s aures

full thickness infection of the epidermis

crusted thick lesion

surface of skin is necrotic = thick and adherent scar

get from an infected insect bite/in people who are immunosuppressed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

describe an abcess *

A

same as boil

collection of pus underneath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe staphyloccocal scaleded skin syndrome

A

staph aures in body

toxin = cleavage of skin in children <5yrs

there is an immune reaction against the toxin

get AB in hospital - flucluxocillin (if resistant = MRSA)

diagnose with swap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

describe trephonema pallidum *

A

gram -ve spirochaete

cause of syphillis - STD

12 million new cases per year worldwide

Increases transmission of HIV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the clinical signs of syphilis *

A

Primary (at 3-8 weeks after initial innoculation)

  • Painless ulcer at inoculation site (Genital or oral)
  • then this disappears, maybe with a scar

Secondary (at 6-12 weeks)

  • Disseminated infection and rapid proliferation
  • Generalised rash and lymphadenopathy

Latent syphilis (no clinical signs) - but have syphilis so can be transmitted especially in pregnancy

Tertiary syphilis (usually years later)

  • Skin, neurological and vascular manifestations

Congenital

  • Acquired perinatally - transfer over placenta
  • Early and late manifestations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

describe primary syphilis *

A

ulcer is called a chancre

blood test will be -ve, need to swap at the region q

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what do you see in dark field microscopy of chancre sample (

A

spirochates - ie spiral shaped bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

describe secondary syphilis *

A

maculopapular rash - widespread, red and blotchy

condyloma lata - warts in perianal, armpit and groin

palms and soles typically involved

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

describe tertiary syphilis *

A

rare

inflammatory destructive lesions of the bone and the skin

can get thoracic aneurysms - dilated thoracic aorta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the effects of neurosyphilis *

A
  • Miscarriage
  • Still birth
  • Prematurity
  • Rashes - like secondary syphilis
  • Brain and neurological problems - like tertiary
  • Bone disease
  • saddle shape nose
  • peg like teeth
  • blind
  • skin lesions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

diagnosis and treatment of syphylis

A

primary - swab

secondary - serology will be positive

plasma cell on rash biopsy suggests syphylis

treatment - penicillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

describe herpes simplex virus *

A

lay latent in certain tissues eg nerves - can reactivate

type 1 - oral herpes, common at the Vermilion border

type 2 - urogenital herpes

clinical presentation

  • Vesicular rash - 2 weeks - painful, tingle, burn - break down and form ulcer
  • Eczema herpeticum
  • Herpes encephalitis

blisters at early stages are vesicles, at later stages are crusty and pustular like vesicles

can get stomatitis - inflammation of whole mouth

can be anywhere in body - not just mouth/orogenital

20
Q

describe eczema herpceticum *

A

eczema means suseptible to staph aures and HSV

can get very ill - need IV acyclovir and supportitive treatment

have punched out ulcers

21
Q

what happens when HSV reactivates *

A

have symptoms in the same place

22
Q

treatment and diagnosis for HSV

A

swab, PCR - 48hr result

acyclovir

councilling about recurrance

23
Q

describe varicella zosta *

A

chickenpox

common in children - mild

more severe in adult - effect brain (encaphalitis), pneumonia in elderly with high mortality

incubation period of about a week

24
Q

what are the clinical sympotms of varicella zoster *

A

2 week crust and then get better

malaise, fever, sore throat

rash, vesicles (groups all over body)

lesions in mouth

25
Q

where are latent varicella zoster *

A

live in dorsal route ganglia

can reactivate

26
Q

describe reactivation of varicella zosta *

A

shingles

rash of pox down a dermatome

erythemetous base

can be bullus - blister

if affect branch of trigeminal will affect the face = painful blister and rash = blindness and chronic pain

27
Q

treatment and diagnosis of herpez zosta

A

diagnosis with swab and pcr

get better by self but give acyclovir

should have shingles vaccination at 70yrs

28
Q

describe EBV

A

infectious mononucleosis

latent in B cell

targets B cells

29
Q

describe CMV

A

infectious mononucleous like syndrome, retinitis

targets monocytes and epithelial cells

latent in lymphocytes

30
Q

describe roseola virus

A

target cell lymphocyte

cause roseola - chilfhood rash

latent in lymphocytes

31
Q

describe HHV7

A

target cell T cell

pityriasis rosea - rash

latent cell lymphocyte

32
Q

describe KS ass herpes virys

A

target - lymphocytes

disease KS - skin cancer from endothelial cells of lymphatics

latency - B cell

33
Q

what are the 2 types of superficial fungal infections *

A

dermatophytes - type of mould

yeast

34
Q

summarise dermatophytes *

A

eg Trichophyton rubrum

Grow in keratin

Long hyphae, grow from tip

35
Q

summarise yeast infections *

A

eg Candida

Grow on warm wet surfaces

single cell and bud

36
Q

describe tinea unguium *

A

dermatophyte infection - trichophyton rubrum

yellow and crumbly nail

to make diagnosis would take clippings and scrape undernail

37
Q

describe tinea capitis *

A

dermatophyte

widespread

prepubertal children - post puberty the sebrum has changed so not effected

if bulky mass with pustules it is a kerion - afrocarribeans are more suseptible because of the shape of hair

can get from people or from animals

38
Q

describe tinea manuum *

A

dematophytes

39
Q

describe tinea pedis *

A

common in people with chronically wet feet

common in toes

40
Q

describe tinea cruris *

A

in groin

scrotum not affected

41
Q

describe tinea facei *

A

fungal infection on face

42
Q

describe candida intertigo *

A

in hot sweaty env

have dots around called satellite lesions

43
Q

how do you diagnose tinea infections

A

scrapings, cuttings, pluckings of hair

can be cultured/PCR

culture takes 4 wks, PCR days

drug for dermatophytes- tibinofine as a cream or tablets

treatment for candida - antifungal creams eg clotrimazole

44
Q

describe scabies - sarcoptes scabei *

A

mite

females burrow into your skin and lay eggs in the stratum cornum

can see little line with black dot at end - dot is the head of the mite

take scrapings and look down microscope and see mite

when 1st infected you are asymptomatic, then after 4 wk - get wide spread eczema because developed allergy to scabies

can get secondary bacterial infection if you have had it for a long time and no treatment - get glomerulonephritis by streptococcus

spread by skin contact for long time

45
Q

what are the sites of the burrows in scabies *

A

finger webs, toe webs

genitals - here get inflammatory nodules rather than burrows

axilla

tummy

flexures of arm

46
Q

treatment for scabies

A

insecticide cream all over body, wash off after 12 hours repeat 5 days later

there is a tablet alternative

microbiology year 2 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions