Bacterial and viral infections

Question 1

Is staphylococcus aureus pathogenic?

Answer 1

It is often pathogenic, but can

inhabit the inner nose as a

symptomless resevoir.

Question 2

Is streptococcus pyogenes pathogenic?

Answer 2

It’s always pathogenic

Question 3

Name the different skin conditions that can be caused by S.aureus and S.pyogenes.

Answer 3

Impetigo

erysipelas

cellulitis

folliculitis

ecthyma

staphylococcal scalded skin syndrome

Question 4

Name the different skin conditions that are 2ry to skin infection.

Answer 4

erythema nodosum

erythema multiforme

vasculitis

necrotising fasciitis

cold sore (herpes simplex)

eczema

Question 5

Who is impetigo common in?

Answer 5

Young children

Question 6

Which organisms often cause impetigo?

Answer 6

staphylococcus aureus and

streptococcus pyogenes

Question 7

What is the Ix/Mx for impetigo?

Answer 7

Swap and culture

Topical antiseptics/biotics (systemic if severe)

Soak off curst with soap and water (as full of bacteria)

Question 8

Who is ecthyma common in?

Answer 8

Diabetics

Immunosuppressed

Question 9

What is the resolution of ecthyma like?

Answer 9

Tends to leave a scar

Question 10

How is ecthyma treated?

Answer 10

Long course (2-4 weeks) of

oral antibiotics

Question 11

Which layers of the skin does impetigo infect?

Answer 11

The epidermis

Question 12

What layer of skin does ecythma infect and what is it linked to?

Answer 12

Linked to impetigo but extends from epidermis to dermis

Question 13

Which layers of the skin are infected in cellulitis?

Answer 13

deeper dermis as well as

the subcutaneous tissues

Question 14

What layers of the skin does erysipelas infect and what is it linked to?

Answer 14

It is linked to cellultis

It is infection of the upper dermis

Question 15

What generally are the causes of cellulitis?

Answer 15

by staphylococcal or

streptococcal disease

Question 16

What is the treatment for cellulitis?

Answer 16

systemic antibiotics

Question 17

What is a common port of entry for cellulitis?

Answer 17

Tinea pedis (which is treatable)

Question 18

How can you distinguish erysipelas and cellulitis?

Answer 18

Erisipelas is more superficial and

has more defined edges

Question 19

What is staphylococcal scalded skin syndrome caused by?

Answer 19

staphylococcal toxins

Question 20

What is the treatment for staphylococcal scalded skin syndrome?

Answer 20

Find source of infection

I.V. antibiotics

Supportive care:

1) Fluids
2) Analgesia
3) Liberal emollients

Question 21

What are the common causes of erythema nodosum?

Answer 21

Streptococcal infection (type IV delayed hypersensitivity response to numerous antigens)

Sarcoidosis

IBD

Question 22

What is the treatment for erythema nodosum?

Answer 22

Treat any underlying condition

NSAIDs

Question 23

How is erthema multiforme treated?

Answer 23

Remove trigger such as:

HSV

Streptococcus

Meds

and it will settle within 2 weeks

Question 24

What is the treatment for vasculitis?

Answer 24

screening for extra-cutaneous disease and

treatment of the underlying problem

Question 25

Other than a rash what symptoms occur in necrotising fasciitis?

Answer 25

Pyrexia Pain in affected area

Question 26

What speed is the progression of the rash in necrotising fasciitis?

Answer 26

rapid progression

Question 27

What is the treatment for necrotising fasciitis?

Answer 27

Life-threatening - thus surgical debridement required

Question 28

Which conditions can be caused by hypersensitivity to streptococcal antigens?

Answer 28

Erythema nodosum erythema multiforme guttate psoriasis vasculitis glomerulonephritis

Question 29

What does HSV cause?

Answer 29

Cold sores and gential herpes

Question 30

What are the lesions caused by HSV called (on the face)?

Answer 30

Vesicles

Question 31

What is the treatment for cold sores?

Answer 31

Topical of systemic acyclovir

Question 32

What areas of the lip will be infected by HSV?

Answer 32

It will affect the same part of a single pt repeatedly

Question 33

What is the treatment for eczema herpeticum?

Answer 33

systemic aciclovir treat the eczema with topical steroids

Question 34

How is varicella zoster virus transmitted and how long does it incubated for?

Answer 34

Respiratory droplets Incubation period of 14-17 days

Question 35

How long is a patient with varicella zoster virus infection (chicken pox) infectious for?

Answer 35

2 days before eruption to a week after onset of eruption

Question 36

What is the risk of adults have chickenpox?

Answer 36

Much higher risk of internal organ involvement

Question 37

What is the risk of shingles of the nasal tip?

Answer 37

involvement of the naso-ciliary nerve (a branch of the ophthalmic nerve (CN V1)) is likely to cause ocular disease which may be sight-threatening

Question 38

What causes shingles?

Answer 38

reactivation of varicella zoster virus (a.k.a. herpes zoster)

Question 39

What is the risk of herpes zoster around the external auditory meatus?

Answer 39

May indicate Ramsay Hunt syndrome, should have associated: facial palsy deafness vertigo

Question 40

What are the risks of shingles infection?

Answer 40

Nasal tip - naso-ciliary nerve involvement + subsequent sight loss Ramsay Hunt syndrome Post-herpetic neuralgia 2ry bacterial infection Encephalitis

Question 41

What is the treatment of shingles?

Answer 41

Must treat before vesicles have stopped forming or its too late. Treatment is aciclovir

Question 42

Where does the varicella zoster virus lay dormant from chickenpox to cause shingles?

Answer 42

The dorsal route ganglion

Question 43

Which type of HPV warts are very resistant to treatment?

Answer 43

Mosaic warts

Question 44

What is the treatment for HPV warts?

Answer 44

cryotherapy or curettage (should eventually spontaneously resolve)

Question 45

What are the typical lesions of molluscum contagiosum like?

Answer 45

Umbilicated papules

Question 46

What are the symptoms associated with the umbilicated papules of molluscum contagiosum?

Answer 46

They are asymptomatic

Question 47

What is the treatment for molluscum contagiosum?

Answer 47

Generally no treatment is required

Question 48

Who does molluscum contagiosum commonly occur in and who is it worse in?

Answer 48

Common in children Worse in atopics