Skin Infections

Question 1

What is ringworm?

Answer 1

Tinea corporis

Question 2

What are the features of tinea corporis?

Answer 2

Scaly, annular lesions on body
Itchy
Spreading
Central clearing

Question 3

What are the common pathogens causing tinea corporis?

Answer 3

Tricophyton rubrum
Microsporum canis
Epidermophyton floccosum

Question 4

Where does tinea pedis occur?

Answer 4

On feet

Question 5

What are two subtypes of tinea pedis?

Answer 5

Interdigital tinea pedis

Moccasin tinea pedis

Question 6

Where does tinea unguium occur?

Answer 6

Nails

Question 7

What region of the body is a reservoir for tinea pedis?

Answer 7

Toenails

Question 8

How is tinea unguium treated?

Answer 8

Too deep to be treated topically

Have to use oral antifungals; eg: terbinafine for 3-6 months

Question 9

What is jock itch?

Answer 9

Tinea cruris

Question 10

Where does tinea capitis occur?

Answer 10

On scalp

Question 11

In whom does tinea capitis occur?

Answer 11

Rare in adults

Can occur in children

Question 12

What is the treatment for tinea capitis and why?

Answer 12

Potentially scarring > needs aggressive treatment with

• Systemic antifungals for 2 months
  
  • Griseofulvin
  • Terbinafine
• Oral steroids

Question 13

How is a diagnosis of tinea confirmed?

Answer 13

Scraping for fungal microscopy and culture

Question 14

What is the management of tinea?

Answer 14

Confirm diagnosis with scrapings and cuture
Topical agents for 3-4 weeks
- Imidazole
- Terbinafine
Extensive skin infections respond to
- Oral griseofulvin for 4 weeks
- Terbinafine
- Itraconazole
- Fluconazole
Look for reservoir

Question 15

Why is the use of cortisone cream contraindicated in the treatment of tinea?

Answer 15

Fungus causing tinea loves it

Question 16

How long is the prodrome for varicella?

Answer 16

2 weeks

Question 17

What are the features of a primary VZV infection?

Answer 17

Fevers
Crops of
- Papules
- Vesicles
- Pustules
- Then crusts
Can be mucosal
Trunk and heads > limbs

Question 18

What causes shingles?

Answer 18

VZV reactivation in dorsal ganglion

Question 19

What are the features of shingles?

Answer 19

Unilateral dermatomal rash
Prodrome
- Neuralgic pain
- Tingling
Eruption of
- Papules
- Vesicles
- Crusts

Question 20

How is shingles diagnosed?

Answer 20

Zoster PCR

Question 21

What is the treatment for shingles?

Answer 21

Systemic antiviral

Question 22

What are the complications of shingles?

Answer 22

Post-herpetic neuralgia

Ophthalmic involvement

Question 23

What causes cold sores?

Answer 23

HSV 1

Question 24

What are the features of cold sores?

Answer 24

Crops of vesicles on lips

Question 25

What is the treatment for cold sores?

Answer 25

Topical/systemic acyclovir/other antiviral

Question 26

What causes genital herpes?

Answer 26

HSV 2

Question 27

What are the features of genital herpes?

Answer 27

Crops of vesicles on genital areas | STI

Question 28

How is herpes diagnosed?

Answer 28

HSV PCR

Question 29

What is the treatment for genital herpes?

Answer 29

Systemic antivirals | May need prophylaxis

Question 30

What should you consider in herpetic infections?

Answer 30

Risk of exposure in pregnancy Infectious disease > isolation Immunosuppressed patients Ophthalmic involvement

Question 31

What is molluscum contagiosum?

Answer 31

Skin infectious caused by molluscum contagiosum virus (MCV)

Question 32

What are the features of molluscum contagiosum?

Answer 32

Common disease of childhood Outbreaks in family common Polymorphous umbilicated skin coloured papules

Question 33

How is molluscum contagiosum managed?

Answer 33

Showers not baths Restrict sharing of bath towels Concurrent eczema treated with topical steroids Topical irritants; eg: salicylic acid wart paint Topical immunostimulants; eg: dilute imiquimod cream Destructive methods; eg: topical cantharidine treatment

Question 34

What causes warts?

Answer 34

HPV types

Question 35

What is the commonest type of wart?

Answer 35

Verruca vulgaris

Question 36

What are other types of warts?

Answer 36

``` Plane Periungual Filliform Mosaic Anogenital > carcinogenic potential in females ```

Question 37

What is the management of viral warts?

Answer 37

``` Depends on - Number - Site - Patient factors Treatments often used in combination Consider when planning - Spontaneous remission rates - Risk of scarring by treatments - Trauma of treatment - Cure rate for placebo ```

Question 38

What is the destructive treatment of viral warts?

Answer 38

Liquid nitrogen cryotherapy Diathermy Curettage

Question 39

What is the topical treatment of viral warts?

Answer 39

Salicylic acid and other keratolytics DCP immunotherapy Imiquimod for genital warts Tape

Question 40

What organisms cause the majority of cutaneous bacterial infections?

Answer 40

Staphylococcus aureus | Group A Streptococcus

Question 41

What usually causes folliculitis?

Answer 41

S aureus

Question 42

How do you investigate folliculitis?

Answer 42

Swab for bacterial culture and sensitivity

Question 43

Where do you look for S aureus carriage?

Answer 43

Nares Axillae Groin

Question 44

How is folliculitis treated?

Answer 44

Systemic antibiotics Eradicate carriage Antiseptic washes helpful in maintenance

Question 45

What causes impetigo?

Answer 45

Exfoliative toxin of S aureus

Question 46

What is the treatment for impetigo?

Answer 46

Anti-Staph antibiotics

Question 47

What are the symptoms associated with cellulitis?

Answer 47

Febrile | Systemically unwell

Question 48

What usually causes cellulitis?

Answer 48

Group A Strep

Question 49

What is the treatment for cellulitis?

Answer 49

IV antibiotics | Severe cases need surgical intervention