Skin Infections

Question 1

Impetigo causative organism

Answer 1

Staph aureus
Strep pyogenes (GAS)

Question 2

Presentation of impetigo

Answer 2

Golder crusting
Inflamed plaques
Around nose and mouth
Children

Question 3

Treatment of impetigo

Answer 3

Topical antibiotics: Fusidic acid (1st), mupirocin (MRSA)
Oral antibiotics (if severe): Flucloxacillin (1st), clarithromycin

Question 4

What is cellulitis?

Answer 4

Infection of the dermis and subcutaneous tissue

Question 5

What is impetigo and how does it spread?

Answer 5

Superficial bacterial infection of the skin

Spread: direct contact, very contagious

Question 6

What is eyrsipelas?

Answer 6

Superficial form of cellulitis caused by infection with group A strep/strep pyogenes

Question 7

Cellulitis causative organism

Answer 7

Staph aureus

Beta-haemolytic strep: (GAS/GBS)

Question 8

Presentation of cellulitis

Answer 8

Generalised swelling, pain, erythema

Question 9

Treatment of cellulitis

Answer 9

Flucloxacillin (or doxycycline if penicillin allergic)

Question 10

What is necrotising fasciitis?

Answer 10

Rapidly progressive infection of the deep fascia causing necrosis of subcutaneous tissue

Question 11

Presentation of necrotising fasciitis

Answer 11

Disproportional pain to visible symptoms (similar to cellulitis)
Feels like bubble wrap

Question 12

Investigation of necrotising fasciitis

Answer 12

Blood culture, deep tissue biopsy and Gram stain to identify causative organism

Question 13

Treatment of necrotising fasciitis

Answer 13

Radical debridement +/- amputation
IV antibiotics (flucloxacillin + clindamycin + gentamicin)

Question 14

Lyme disease causative organism and vector

Answer 14

Borreli burgdoferi

Ticks

Question 15

Lyme disease presentation

Answer 15

Erythema migrans (bullseye lesion)

Question 16

Complications of Lyme disease

Answer 16

Heart block
Nerve palsies
Arthritis

Question 17

Treatment of Lyme disease

Answer 17

Amoxicillin or doxycycline

Question 18

Chickenpox spread

Answer 18

Air droplets

Question 19

Chickenpox and shingles causative organism

Answer 19

Varicella zoster virus

reactivation in shingles

Question 20

Chickenpox presentation

Answer 20

Fever
Itch
Macules –> papules –> vesicles –> scabs
Centripetal (rash is concentrated at the centre of the body)

Question 21

Complications of chickenpox

Answer 21

Secondary bacterial infection
Pneumonitis
Haemorrhagic rash
Encephalitis

Question 22

Treatment of chickenpox

Answer 22

Goes away itself (week)

Don’t take ibuprofen as it can cause skin infections

Question 23

Presentation of shingles

Answer 23

Tingling/pain –> erythema –> vesicles –> crusts

Rash restricted to one dermatome

Question 24

Complications of shingles

Answer 24

Post-herpetic neuralgia

Question 25

Treatment of shingles

Answer 25

No definitive treatment Aciclovir can aid recovery Vaccine for chickenpox can be used in high titre preparations in elderly patients to reduce the impact of shingles

Question 26

Other names of erythema infectiosum

Answer 26

Fifth disease | Slapped cheek

Question 27

Erythema infectiosum causative organism

Answer 27

Parvovirus B19

Question 28

Presentation of erythema infectiosum

Answer 28

Red cheeks with palpable raised edge (slapped cheek)

Question 29

Complications of erythema infectiosum

Answer 29

Arthritis and joint pain Aplastic crisis Spontaneous abortion

Question 30

Hand, foot and mouth disease causative organism

Answer 30

Enteroviruses: e.g. coxsackie virus

Question 31

Presentation of hand, foot and mouth disease

Answer 31

``` Sore throat Fever Not wanting to eat Mouth ulcers Red spots that become blisters on the hands and feet ```

Question 32

Complications of hand, foot and mouth disease

Answer 32

Viral meningitis | Encephalitis

Question 33

HSV-1 causes...

Answer 33

Infections above the waist (generally) Causes half of genital herpes Main cause of oral lesions Primary gingivostomatitis

Question 34

HSV-2 causes...

Answer 34

Infections below the waist (generally) | Causes half of genital herpes

Question 35

Investigations for herpes

Answer 35

Swab of lesion in virus transport medium: PCR for detection or viral DNA Antibody tests: Where virus infected site is inaccessible

Question 36

What animal can you get orf from?

Answer 36

Sheep infected with parapoxvirus

Question 37

Presentation of orf

Answer 37

Firm, fleshy nodules on hands

Question 38

Treatment of candida infection

Answer 38

Antifungals: clotrimazole (topical), nystatin (topical), fluconazole (oral)

Question 39

Candida

Answer 39

Fungal infection in skin folds where area is warm and moist

Question 40

Tinea (ringworm)

Answer 40

Fungal infection of the skin, scalp or nail

Question 41

Investigations for tinea

Answer 41

Skin scrapings, nail clippings, hair: for microscopy + culture and fluorescence under Woods light

Question 42

Treatment of tinea

Answer 42

Small areas: clotrimazole (topical), terbinafine (topical), amorolfine (topical nail paint) Widespread infection: terbinafine (oral, when nails are affected too), itraconazole (last resort drug, has many interactions)

Question 43

Presentation of lice (pediculosis)

Answer 43

Intense itch

Question 44

Treatment of lice (pediculosis)

Answer 44

Malathion

Question 45

Scabies causative organism

Answer 45

Sarcoptes scabiei

Question 46

Presentation of scabies

Answer 46

Intense itch (particularly at night) Areas: finger webs, wrists, genitals Burrows can also be seen

Question 47

Treatment of scabies

Answer 47

Permethrin lotion (1st line) Malathion Benzyl benzoate (not in children) Anti-pruritic