Brainscape's Knowledge GenomeTM

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


See full index

brs2 > derm - infections and infestations > Flashcards

derm - infections and infestations Flashcards

1
Q

what conditions can staph aureus infection cause

A 
ecthyma
impetigo
cellulitis
folliculitis: furunculosis, carbuncles
staph scalded skin syndrome
superinfects other dermatoses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how does staphylococcus cause infections

A

expresses virulence factors e.g toxins, haemolysin, leukocidin, peptidoglycan layers etcc that confer pathogenic properties

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

what virulence does strept possess that leads to infections

A

strept pyogenes - attaches to epithelial surface via lipoteichoic acid portion of fimbriae

  • has m proteins (antiphagocytic) and hylauronic acide capsule
  • produces erthrogenic exotoxins
  • produces streptolysins S and O
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what conditions can strept cause

A 
ecthyma
cellulitis
impetigo
erysipelas
scarlet fever
necrotising fascitis
superinfects other dermatoses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is folliculitis

A

follicular erythema - sometimes pustular
can be infectious/non infectious
recurrent cases may arise from nasal carriage of ataph aureus particularly strains expressing pvl
eosinophilic(non infectious) is associated with hiv

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

what are the treatments for follicultis

A

antibiotics - usually flucloxacillin or erythromycin

incision and drainage is required for furunculosis

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

what is difference between furuncle and carbuncle

A 
furuncle = deep follicular abcess 
carbuncle = composes or furuncles and involves adjacent hair follicles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

why do some patients develop recurrent staph impetigo or recurrent furunculosis

A 
have established themselves as part of resident microbial flora (in particular nasal flora)
immunodeficiencies :
-hypogammaglobulinaemia
- chronic granulomatous disease
- AIDS
- diabetes mellitus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is panton valnetine leukocidin staph aureus

pvlsa

A

beta pore forming exotoxin
causes leukocyte destruction and tissue necrosis
= higher morbididity,mortality and transmissibility
in skin: recurrent and painful abcesses, follliculitis and cellulitis
*often painful, more than one site, recurrent, present in contacts
extracutaneous: necrotising pneumonia, necrotising fascitis and purpura fulminans

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

what are the 5c’s risk of acquiring pvla

A 
close contact e.g hugging, contact sports
contaminated items
crowding
cleanliness
cuts and grazes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the treatment for pvla

A

antibiotics - tetracycline
decolonisation e.g chlorhexidine body wash for 7 days
nasal application of mupirocin ointment for 5 days
treatment of close contacts

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

what is psedomonal follicultis

A

associated with hot tub use, swimming pools and wet suits
appears 1-3 days after exposure, as diffuse truncal eruption
causes follicular erythematous papule
rarely - abcesses, lyphangitis and fever
most cases self limited - no treatment req
severe/recurrent cases can be treated with oral ciprofloxacin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is cellulitis

A

infection of lower dermis and subcut tissue
tender swelling with ill defined,blanching erythema or oedema
most causes = strept pyogenes and staph aureus
oedema = predisposing factor

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

what is the treatment for cellulitis

A

systemic antibiotics

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

what is impetigo

A

superficial bacterial infection, stuck on honey coloured crusts overlyig an erosion
caused by strepttococci (non bullous) or staph (bullous)
caused by exfoliative toxins a and b, split epidermis by targeting desmoglein 1.
affects face: perioral, ears and

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

treatment of impetigo

A

treatment with topical and with or without systemic antibiotics

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

what is impetiginisation

A

refers to superficial infections
occurs in atopic dermatitis
typically gold crust and caused by staph aureus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is ecthyma

A

severe form of strept impetigo
-thick crust overlying punch out ulceration surrounded by erythema
usually in lower extremities

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

what is staph scalded skin syndrome

A

usually in neonates, infants and immunocompromised adults
due to exfoliative toxin
infection occurs at distant site i.e conjunctivitis/abcess
organism cannot be cultured from denuded skin
in neonates - kidneys cannot excrete exfoliative toxin quickly
diffuse tender erythema with rapid progression leads to flaccid bullae, wrinkle and exfoliate leaving oozing erythematous base
clinically resembles sjsten

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is toxic shock syndrome

A

febrile illness caused by group a staph aureus strain that produces pyrogenic exotoxin tsst1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

signs and symptoms of toxic shock syndrome

A

fever >38.9
hypotension
diffuse erythema
involvement of: gi,muscular,cns,renal and hepatic systems
mucous membranes - erythema
haematological (plts <1000000)
desquamation of palms ans soles 1-2 wks after resolution of erythema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is erythrasma

A

infection of corynebacterium minutissiumum
well demarcated patches in interriginous areas
initially pink and becomes brown and scaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is pitted keratolysis

A

pitted erosions of soles

caused by corynebacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is pitted keratolysis treated by

A

topical clindamycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is eryspipeloid

A

erythema and oedema of hand after handling of raw fish/meat
extends slowly over weeks
caused by erysipelothrix rhusiopathiae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is anthrax

A

painless necrotic ulcer with surrounding oedema and regional lymphadenopathy (with pain in lymph nodes) at site of contact with hides, bone meal or wool infected with bacillus antracis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is blistering distal dactylitis

A

rare infection caused by strept pyogenes or staph aureus
typically in young children
1/more tender superficial bullae on erythematous base on volar fat pad of a finger
toes may rarely be affected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is erysipelas

A

infection of deep dermis and subcutis
casued by beta haemolytic strept or staph aureus
painful
prodrome of malaise,fever and headache
presents as erythematous indurated with sharply demarcated border and cliff drop edge +- blistering
face and limb +- red streak of lymphangitis and local lymphadenopathy
portal of entry must be sought e.g tinea pedis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

how is erysipelas treated

A

with intravenous antibiotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what is scarlet fever

A

disease of children
caused by upper rti with erythrogenic toxin producing strept pyogenes
preceded by sore throat,headache, malaise,chills, anorexia and fever
eruption begins 12-48 hrs later
- blanchable tiny pinkish red spots on chest,neck and axillae
- spread to whole body within 12 hrs
- sandpaper like texture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what are some complication of scarlet fever

A 
otitis
mastoiditis
sinusisitis
pneumonia
myocarditis
hepatitis
meningitis
rheumatic fever
acute glomerulonephritis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what is necrotising fasciitis

A

initial dusky induration (usually of limb) followed by rapid painful necrosis of skin, connective tissue and muscle
- potentially fatal
usually synergistic: strept,,staph,enterobacteriacae and anaerobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

treatments/diagnosis for necrotising fasciitis

A

prompt diagnosis essential followed by broad spectrum parenteral antibiotics and surgical debridement
mri can aid diagnosis
blood and tissue cultures determine organisms and sensitivities
mortality is high
can affect scrotum - fourniers gangrene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what is atypical mycobacterial infection

A

important cause of infection in immunocompromised states

  • mycobacterium marinum causes indolent granulomatous ulcers(fish- granuloma) in healthy people, sporotrichoid spread
  • mycobacterium chelonae and abcesses - puncture wounds, tattoos, skin trauma or surgery
  • mycobacterium ulcerans - important cause of limb ulceration in africa (buruli ulcer) or australia (searles ulcer)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what is borreliosis(lymes disease)

A

annular erythema develops at site of borrelia infected tick
bite form ixodes tick infected with borrelia burgdorferi
initial cutaneous manifestations - erythema migran - only 75%
- erythematous papule at bite site
- progression to annular erythema of >20cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what can occur 1-30 days after infection, fever and headache in lyme disease

A

multiple secondary lesions develop - similar but smaller to initial lesions

  • neuroborreliosis: facial palsy/other cn palsies, asesptic meningitis, polyradiculitis
  • arthritis - painful and swollen large joints
  • carditis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

how to diagnose lyme disease

A

serology not sensitive and histology is non specific therefore high index of suspicion is used to make diagnosis and based of clinical features

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what is tularaemia

A

caused by francesella tularensis
acquired through: handling infected animals,tick bites and deerfly bites
- ulceroglandular form
- primary skin lesions is small papules at innoculation site that rapidly necrosis leading to painful ulceration
+- local cellulitis
painful regional lymphadenopathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what are the systemic features of tularaemia

A

fever, chills, headache and malaise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what is ecthyma gangrenosum

A

pseudomonas aeruginosa
usually occurs in neutropaenic patients
red macules - oedematous - haemorrhagic bullae
- may ulcerate in late stages/form eschar surrounded by erythema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what is syphilis

A

caused by treponema pallidum
primary infection chancre - painless ulcer with firm indurated border
painless regional lymphadenopathy one week after primary chancre
chancre appears within 10-90 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what is secondary syphilis

A 
begins 50 days after chancre
skin manifestations: 
pityriasis rosea like rash
allopecia
mucous patches
lymphademopathy
residual primary chancre
condylomata lata
hepatosplenomegaly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

symptoms of secondary syphilis

systemic symptoms

A 
malaise
fever
headache
pruritus
loss of appetite
iritis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

what is lues maligna

A

rare manifestation of secondary syphilis
pleomorphic skin lesions with pustules,nodules and ulcers with necrotising vasculitis
more frequent in hiv maifestations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what is tertiary syphilis

A

glumma skin lesions - nodules and plaques
extend peripherally while central areas heal with scarring and atrophy
mucosal lesions extend to and destroy nasal cartilage
can also develop cvd and neurosyphilis

46
Q

how to diagnose syphilis

A

clinical findings
serology
strong index of suspicion required in secondary syphilis

47
Q

what is the treatment for syphilis

A

im benzylpenicillin or oral tetracycline

48
Q

what is leprosy

A

caused by mycobacterium leprae

obligate intracellular bacteria - predominantly affects skin and nerves but can affect any organ

49
Q

what is the difference between lepromatous leprosy and tuberculoid leprosy

A

lepromatous :
- multiple lesions: macules,papules and nodules
sensation and sweating normal early on
tuberculoid: solitary or few lesions with elavated borders, atrophic center sometimes annular
hairless,anhidrotic,numb

50
Q

what is tuberculosis

A

can affect any organ incl skin
only 5-10% lead to clinical disease
caused by mycobacterium tuberculosis

51
Q

how can cutaneous tuberculosis be acquired

A

exogenously - primary innoculation tb and tuberculosis verrucosa cutis
contigous endogenous spread - scrofulderma or autoinnoculation can develop into periorificial tuberculosis
haematogenous/lymphatic endogenous spread - dissemination( lupus vulgaris, miliary tb, gummas)

52
Q

what are the investigations for tuberculosis

A

interferon gamma release assay
histology - zn stain
culture/pcr

53
Q

what is tuberculous chancre

A
  • painless, firm, reddish brown papulonodule that forms ulcer
54
Q

what is tuberculosis verrucosa cutis

A

wart like papule that evolves to form redbrown plaque

55
Q

what is scrofulderma

A

subcutaneous nodule with necrotic material - becomes fluctuant and drains, with ulceration and sinus tract formation

56
Q

what is orificial tb

A

non healing ulcer of nasal mucosa that is painful

57
Q

what is lupus vulgaris

A

red brown plaque +- central scarring and ulceration

58
Q

what is miliary tb

A

pinhead sized, bluish red papules capped by minute vesicles

59
Q

what is tuberculous gumma

A

firm subcutaneous nodules, later ulcerates

60
Q

what is molluscum cantagiosum

A

poxvirus infection
common in children and immunocompromised
usually resolves spontaneously

61
Q

what is the differential diagnosis for molluscum contagiosum

A

verrucae
condyloma acuminata
basal cell carcinoma
pyogenic granuloma

62
Q

what are the treatment options for molluscum contagiosum

A

curettage
imiquimod
cidofovir

63
Q

what is herpes simplex virus

A

primary and recurrent vesicular eruptions
favour orolabial and genital regions
transmission can occur even during asymptomatic periods of viral shedding

64
Q

how does hsv 1 spread

A

direct contact with contaminated saliva/ other oral secretions
virus replicates at mucocutaneous site of infection
travels by retrograde axonal flow to dorsal root ganglia

65
Q

how does hs2 spread

A

sexual contact

66
Q

what are the symptoms of hsv

A

symptoms occur within 3-7 days of exposure
preceded by tender lymphadenopathy, malaise, anorexia +- burning and tingling
painful rouped vesicles on erythematous base -> ulceration/pustules/erosions with scalloped border
crusting and resolution within 2-6 weeks
orolabial lesions - often asymptomatic
genital involvement - often excruciatingly painful -> urinary infection
systemic manifestations - aseptic meningitis in upto 10% of women
reactivation - spontaneous, uv, fever, local tissue damage, stress

67
Q

what is eczema herpeticum

A

emergency

monomorphic punched out erosions - excoriated vesicles

68
Q

how is eczema herpeticum treated

A

intravenous acyclovir accompanies by antibiotics for superinfections with staph aureus or strept

69
Q

whatis hepatic whitlow

A

hsv 1>2 infection of digits - pain swelling and vesicles
misdiagnosed as paronychia or dactylitis
often in children

70
Q

what is hepres gladiatorum

A

hsv1 involvment of cutaneous site reflecting sites of contact with another athletes lesion
contact sports e.g wrestling

71
Q

what is neonatal hsv infection

A

exposure to hsv during vaginal delivery - risk higher when hsv acquired near time of delivery
hsv1/2
onset from birth to 2 wks
locally usually - on scalp/trunk
vesicles - bullae erosions
encephalitis - mortality >50% without treatment, 15% with treatment, can lead to neurological deficits

72
Q

how to treat neonatal hsv

A

requires iv antivirals

73
Q

what is severe/chronic hsv

A

immunocompromised patients e.g hiv/transplant recipients
most common presentation - chronic enlarging ulceration
often atypical e.g verrucous, exophytic or pustular lesions
involvement of resp/gi tract can occur

74
Q

how to diagnose for hsv

A

swab for polymerase chain reaction

75
Q

what is treatment for hsv

A

dont delay!
oral valacyclovir/acyclovir 200mg 5 times daily in immunocimpetent localised infections
intravenous 10mg/kg tds

76
Q

what is varicella zoster virus

A

is dermatomal disease

can affect singledermatomes or multidermatomal

77
Q

what is hand foot and mouth disease

A

caused by coxackie a16, echo71
an acute self limiting coxsackievirus infection
prodrome of fever, malaise and sore throat
spread by direct contact via oral oral route and oral faecal route

78
Q

how does hand foot and mouth disease present

A

red macules, vesicles and ulcers develop on buccal mucosa, tongue,palate and pharynx - may also develop on hand and feet

79
Q

what viruses cause morbilliform( measle like) eruptions

A 
measles
rubella
ebv
cmv
hhv6
hhv7
leptospirosis
rickettsia
80
Q

what causes petechial/purpura infestations

A

coagulation abnormalities
vasculitis
infections
viruses - hep b, cmv, rubella, yellow fever, dengue fever, west nile virus
bacterial - borrelia, rickettsia, neisseria,endocarditis
other: plasmodium falciparum, trichnella,ten,ergot poisoning raynauds

81
Q

what is giannoti crosti syndrome

A

papular acrodermatitis of childhood
viral eruption that causes acute symmetrical erythematous papular eruption on face,extremities and buttocks - usually age 1-3 yrs

82
Q

what are the causes of gianotti crosti syndrome

A 
ebv - most common
cmv
hhv6
coxsackie virus a16,b4,b5
hep b
83
Q

what is erythema infectiosum

A

parovirus b19
initially mild fever and headache
few days later = slapped cheeks for 2-4 days
ten reticulated rash of chest and thighs in 2nd stage

84
Q

what is roseola infantum

A 
aka exanthem subitum aka 6th disease
common in children 
2-5 days high fever
followed by appearance of small pale pink papules on trunk and head
last hrs to 2 days
caused by hhv6 and hhv7
85
Q

what is orf

A

Caused by parapoxvirus
direct exposure to sheep or goats
dome shaped, firm bullae that develop umbilicated crust
usually develop on hands and forearms
generally resolve without therapy in 4-6 wks

86
Q

what are warts

A

caused by 200 subtypes of hpv

87
Q

what are superficial fungal infections caused by

pity:

A

hypopigmented, hyperpigmented or erythematous macular eruption +- fine scale
caused by malassezia spp
begins during adolescence when sabaceous glands become active
flares when temperatures and humidity are high - immunosuppression

88
Q

what are superficial fungal infections treated with

A

topical azole

89
Q

what are dermatophytes

A

fungi that live on keratin

90
Q

what causes the most fungal infections

A

trichophytan tonsurans

91
Q

what is kerion

A

an inflammatory fungal infection that may mimic a bacterial folliculitis or an abscess of scalp.
scalp is tender and patient usually has posterior cervical lymphadenopathy
- frequently secondarily infected with staph aureus

92
Q

what is tinea pedis

A 
trichophyton rubrum - scaling and hyperkeratosis of plantar surface of food
trichophyton mentagrophytes( interdigitale) - sometimes vesiculobullous reaction on arch/side of foot
93
Q

what is an id infection

A

aka dermatophytid reaction
inflammatory reactions at sites distant from associated dermatophyte infection
may include urticaria, hand dermatitis or erythema nodosum
likely secondary to host immunologic response against fungal antigens

94
Q

what us majocchi granuloma

A

follicular abscess produced when dermatophyte infection penetrates follicular wall into surrounding dermis: tender
trichophyton rubrum/ mentagrophytes are usually culprit

95
Q

what is candidiasis

A

caused by candida albicans
predisposed by occlusion, moisture, warm temp, diabetes m
most sites show erythema oedema, thin purulent discharge
usually an intertriginous infection (affecting axillae, submammary folds, cururae and digital clefts) or of oral mucosa
common cause of vulvovaginitis
may affect mucosae
can be systemic - immunocompromise

96
Q

what are deep fungal infections

A 
capacity for deep invasion of skin or production of skin lesions secondary to systemic visceral infection
subcutaneous fungal infections - infections of implantations (inoculation)
- sporotrichosis
- phaeohypomycosis
- chromomycosis
- mycetoma
- lobomycosis
- rhinospordiosis
97
Q

what do systemic resp endemic fungal infections include

A 
blastomycosis
histoplasmosis
coccidiomycosis
paracoccidoiomycosis
penicillinosis
disease in both immunocompetent and immunosupressed
98
Q

what is a risk factor for aspergillosis

A

neutropaenia and corticosteroid therapy

99
Q

what is aspergillosis

A

primarily resp pathogen
cutaneous lesions being well circumscribed papule with necrotic base and surrounding erythematous halo
propensity to invade blood vessels causing thrombosis and infarction
lesions destructive - may extend into cartilage, bone and fascial planes
should be considered in differential of necrotising lesions
fusarium causes similar illness and cutaneous lesions both clinically and histologically

100
Q

what is presentation of mucormycosis

A

fever, headache, facial oedema, proptosis, facial pain, orbital cellulitis +- cranial nerve dysfunction

101
Q

what can mucormycosis be caused by

A

apophysomyces, mucor, rhizopus, absidia, rhizomucor

102
Q

what are the associations with mucormycosis

A 
diabetes mellitus
malnutrition
neutropenia
meds: steroids/antibiotics/desferoxamine
burns
hiv
103
Q

what is the treatment for mucormycosis

A

aggressive debridement and antifungal therapy

- culture positive in only 30% of cases

104
Q

what are scabies

A

contagious infestations caused by sarcoptes species
female mates, burrows into upper epidermis, lays eggs and dies after one month
affects interdigital areas of digits, volar wrists, axillary areas, genitalia

105
Q

what is hyperkeratosis

A

crusted/norwegian scabies

often asymptomatic - found in immunocompromised individuals

106
Q

what is the treatment for scabies

A

permethrin
oral ivermectin
- 2 cycles of treatment are required

107
Q

what are head louse

A

pediculus humanus capitis
entire life cycle spent in haor
secondary infection common

108
Q

what is the treatment for head louse

A

malathion
permethrin
oral ivermectin

109
Q

what is body louse

A

pediculus humanus corporis
lives and reproduces in clothing - lives to feed, rarely found on skin
- pruritic papules and hyperpigmentation
- found in overcrowding, poverty and poor hygiene
- eliminated by thorough cleaning/discarding clothes

110
Q

what is pubic louse

A

phithrus pubis aka crabs - 3 pairs of legs

eggs found on hair shaft, also found in occipital scalp, body hair, eyebrow and eyelash, axillary hair

111
Q

what is the treatment for pubic louse

A

malathion/permethrin

oral ivermectin

112
Q

what are bedbugs

A

climex lectularis - reddish browb, wingless insect

itch weals around central punctum

brs2 (65 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions