Skin Infections

Question 1

what are the 3 bacterial skin infections

Answer 1

impetigo, cellulitis, necrotising fasciitis

Question 2

what is impetigo?

Answer 2

infectious disease affecting kids spread by direct contact

Question 3

what is the appearance of impetigo?

Answer 3

inflamed plaques with a golden/ crusted surface around mouth and nose

Question 4

organisms responsible for impetigo?

Answer 4

staphylococcus aureus, streptococcus pyogenes

Question 5

mx for impetigo?

Answer 5

topical fusidic acid & avoid school/work until lesions dry

Question 6

what is the main complication of impetigo?

Answer 6

toxin induced bullous impetigo- abs tx (fluclox / erythromycin)

Question 7

what is cellulitis

Answer 7

infection of the skin and soft tissue underneath

Question 8

aetiology of cellulitis

Answer 8

skin barrier breach

Question 9

organisms of cellulitis

Answer 9

staphylococcus aureus, streptococcus pyogenes (GroupA) or GroupB, immunocompromised usually gram -ve/anaerobes

Question 10

s/s of cellulitis

Answer 10

cardinal signs of inflammation, leather like, may have golden yellow crust if staph A, generalised swelling

Question 11

common areas of cellulitis

Answer 11

lower leg/arm, peri-anal, peri-orbital

Question 12

what is the classification for cellulitis

Answer 12

Eron Classification 
1- no systemic toxicity or morbidity 
2- systemic toxicity or comorbidity 
3- significant systemic toxicity / significant comorbidity 
4- sepsis

Question 13

mx for cellulitis

Answer 13

elevate, analgesia, splint, abx (fluclox, clarithromycin, clindamycin, co-amoxi)

Question 14

what is necrotising fasciitis

Answer 14

rapidly spreading, deeper bacterial infection of subcutaneous tissues

Question 15

necrotising fasciitis usually occurs following _____ / _____

Answer 15

trauma / surgery

Question 16

what are the 2 types of necrotising fasciitis

Answer 16

T1: mix of aerobic/ anaerobic bacteria
T2: group A streptococci, spontaneous

Question 17

what is a very rare cause of necrotising fasciitis

Answer 17

vibrio species (asiatic cholera)

Question 18

s/s of NF?

Answer 18

severe pain that is unproportional to degree of skin inflammation, high WBC/CRP

Question 19

abx for NF?

Answer 19

benzylpenicillin & clindamycin

Question 20

surgical mx of NF?

Answer 20

surgical debridement and exploration- may result in amputation

Question 21

what are the viral skin infections studied?

Answer 21

chicken pox 
herpes simplex virus 
erythema multiforme
molluscum contagiosum
warts 
herpangina 
erythema infectosum (slapped cheek disease)
Orf
syphillis 
Lyme disease 
zika

Question 22

what is chickenpox and shingles?

Answer 22

chickenpox- primary infection

shingles- reactivation

Question 23

T/F: shingles happens in kids

Answer 23

F: in adults, chickenpox in kids

Question 24

what is the organism that causes chicken pox?

Answer 24

varicella zoster virus

Question 25

s/s of chickenpox and shingles

Answer 25

chickenpox: macules> papules > vesicles > scabs fever, headache, itch* shingles: tingling pain to erythema > vesicles (one sided only) > curses + neuralgic pain (dermatomal distribution)

Question 26

mx for chickenpox?

Answer 26

live attenuated vaccine | + stay away from school, loose clothes, paracetamol

Question 27

when do you give antivirals (acyclovir) for CP?

Answer 27

>16yo and susceptible population

Question 28

mx of shingles?

Answer 28

may take up to 4 weeks, acyclovir if immunocompromised or if CN involvement, stay off work

Question 29

complication of chicken pox?

Answer 29

pneumonia

Question 30

complication of shingles?

Answer 30

post herpetic neuralgia

Question 31

herpes simplex virus s/s?

Answer 31

extensive ulceration in and around mouth, lasts 1 week, blistering rash at vermillion border

Question 32

types of HSV?

Answer 32

t1: oral lesions, genital herpes, encephalitis t2: genital herpes, oral lesions less common, encephalitis

Question 33

T/F: cold sores are t1 HSV related?

Answer 33

T

Question 34

Ix for HSV?

Answer 34

clinical or HSV DNA in vesicle fluid sample via PCR

Question 35

mx of HSV?

Answer 35

oral valaciclovir, acyclovir for T2/ cold sores

Question 36

complications of HSV?

Answer 36

other HSV infections- corneal ulcers, eczema herpeticum, chronic peri-anal ulceration

Question 37

s/s of erythema multiform?

Answer 37

target lesions with erythema on the distal limbs with mucosal involvement e.g. conjunctivitis

Question 38

describe the target lesions of erythema multiform?

Answer 38

concentric rings of erythema with dusky centre

Question 39

aetiology of erythema multiform?

Answer 39

drug reaction, HSV infection, off, mycoplasma

Question 40

mx of erythema multiform?

Answer 40

self limiting, recurrence- acyclovir

Question 41

what organism is responsible for molluscum contagiosum?

Answer 41

pox virus

Question 42

s/s of molluscum contagiosum?

Answer 42

fleshy, firm, umbilicate, pearlescent nodules

Question 43

mx for molluscum contagiosum?

Answer 43

lasts months but is self-liming, liquid nitrogen (cryo) therapy

Question 44

what are warts?

Answer 44

small lumps of skin caused by human papilloma virus

Question 45

types of warts?

Answer 45

common warts plantar warts (verrcuae)- flattened papillomatous surface, may be tender plane warts: flesh coloured flat-topped lesions, multiple anogenital warts

Question 46

how are warts spread?

Answer 46

direct contact

Question 47

tx for warts?

Answer 47

may spontaneously clear, keratolytic agents (salicylic acid), cryotherapy

Question 48

organism responsible for herpangina?

Answer 48

enteroviruses- coxsackie, echovirus

Question 49

s/s of herpangina?

Answer 49

blistering rash of back and mouth

Question 50

foot and mouth is a coxsackie caused subtype of which disease?

Answer 50

herpangina

Question 51

erythema infectosum is also known as what?

Answer 51

slapped cheek disease

Question 52

what is erythema infectosum?

Answer 52

viral infection that causes blotched or raised red rash and a slapped cheek appearance

Question 53

what is the organism that causes erythema infectosum

Answer 53

parvovirus B19

Question 54

s/s of erythema infectosum?

Answer 54

fever, slapped cheek rash, lacy rash on arms/ legs/ trunk | in adults wrist arthritis may be present

Question 55

ix for erythema infectosum

Answer 55

AB testing for parvovirus

Question 56

mx for erythema infectosum?

Answer 56

supportive- symptomatic tx

Question 57

complications of erythema infectosum?

Answer 57

abortion, aplastic crisis (drop in haemoglobin), anaemia

Question 58

what is Orf

Answer 58

pox virus infection mainly affecting mouth

Question 59

T/F: Orf is caused by Pox virus transmitted via monkeys

Answer 59

F: Pox virus transmitted via sheep and goats therefore more common in farmers and young kids at petting zoos

Question 60

s.s of Orf?

Answer 60

red papule on hands with inflamed blistering border

Question 61

mx for Orf?

Answer 61

self-limiting

Question 62

T/F: syphilis is sexually transmitted

Answer 62

T

Question 63

types of syphilis

Answer 63

1y: chancre present (painless ulcer at site of entry) 2y: red rash over body + oral lesions 3y: CNS and CV involvement

Question 64

what is the bacterium responsible for syphilis?

Answer 64

treponema pallidum

Question 65

mx for syphilis

Answer 65

penicillin injection

Question 66

epi of Lyme disease?

Answer 66

countryside- May to September

Question 67

organism that carries Lyme disease?

Answer 67

tick which carries borellia burgdorferi bacterium

Question 68

s/s of Lyme's?

Answer 68

early- erythema migrant (bull's eye), fever, headache | late- heart block, nerve palsies, arthritis

Question 69

tx for Lyme's?

Answer 69

doxycycline/ amoxicillin

Question 70

Zika virus is found in which countries?

Answer 70

tropical- Brazil*

Question 71

organism of Zika and its vector?

Answer 71

aedes aegypti carried by mosquito

Question 72

s/s of Zika?

Answer 72

fever, maculopapular rash, headaches, arthralgia, myalgia, non-purulent conjunctivitis

Question 73

mx of zika?

Answer 73

self resolves 2-7 days after onset

Question 74

main complications of Zika

Answer 74

pregnant women as may cause microcephaly, G-B syndrome