Skin infections

Question 1

What are erysipelas and cellulitis

Answer 1

Spreading bacterial infections of the skin

Question 2

What part of the skin does cellulitis involve

Answer 2

Deep subcutaneous tissue

Question 3

What parts of the skin does erysipelas involve?

Answer 3

Dermis and upper subcutaneous tissue

Question 4

How is erysipelas distinguished from cellulitis?

Answer 4

Erysipelas has a raised well defined, red border

Question 5

Which bacteria cause erysipelas and cellulitis?

Answer 5

Staphylococcus aureus and streptococcus pyogenes

Question 6

How are erysipelas and cellulitis managed?

Answer 6

Antibiotics (flucloxacillin and benzylpenicillin)

Supportive care including bed rest, leg elevation, sterile dressings and analgesia

Question 7

What are the complications of erysipelas and cellulitis

Answer 7

Local necrosis
Abscess
Septicaemia

Question 8

What are the risk factors for erysipelas and cellulitis infection

Answer 8

Immunosuppression
Ulcers
Wounds
Toeweb intertrigo
Minor skin injury

Question 9

How may someone with erysipelas or cellulitis present?

Answer 9

Most common in lower limbs
Local signs of inflammation - tumor (swelling), calor (warmth), dolor (pain), rubor (erythema)
Systemically unwell with fever, lymphangitis, malaise or rigors

Question 10

Which age group commonly gets staphylococcal scaled skin syndrome

Answer 10

Infants and early childhood

Question 11

What causes staphylococcal scaled skin syndrome

Answer 11

Production of a circulating epidermolytic toxin from phage group II, benzylpenicillin resistant (coagulase positive) staphylococci

Question 12

How does staphylococcal scaled skin syndrome present?

Answer 12

Develops within a few hours to days and may be worse over the face, neck ,axilla and groin
A scaled skin appearance is followed by large flaccid bulla
Perioral crusting is common
There is intraepidermal blistering in this condition
Lesions are painful
Sometimes the eruption is more localised
Recovery within 5-7days

Question 13

How can staphylococcal scaled skin syndrome be managed

Answer 13

Antibiotics- penicillinase resistant penicillin, fusidic acid, erythromycin or appropriate cephalosporin
Analgesia

Question 14

List the 3 main groups of fungi causing skin infections

Answer 14

Dermatophytes
Moulds
Yeasts

Question 15

Give examples of dermatophytes

Answer 15

Tinea/ringworm

Question 16

Give examples of yeasts

Answer 16

Candidiasis

Malassezia

Question 17

Give examples of moulds

Answer 17

Aspergillus

Question 18

What does presentation of fungal skin infection vary with?

Answer 18

The site of infection

Question 19

Describe the presentation of tinea corporis

Answer 19

Tinea infection of the trunk and limbs

Itchy, circular/annular lesions with clearly defined, raised and scaly edge

Question 20

Describe the presentation of tinea cruris

Answer 20

Very itchy
Groin and natal cleft
Circular/annular lesions with clearly defined, raised and scaly edge

Question 21

Describe tinea capitis

Answer 21

Ringworm infection of the scalp

Patches of broken hair, scaling and inflammation

Question 22

Describe the presentation of tinea pedis (athletes foot)

Answer 22

Moist scaling and fissuring in toe webs, spreading to the sole and dorsal aspect of the foot

Question 23

Describe the presentation of tinea manuum

Answer 23

Infection of the hand

Scaling and dryness of the palmar creases

Question 24

Describe the presentation of tinea unguium

Answer 24

Infection of the nail
Yellow discolouration
Thickened, crumbly nail

Question 25

What may happen when tinea is treated with corticosteroids

Answer 25

Tinea incognito - less scaly and ill defined lesions

Question 26

Describe candidiasis presentation

Answer 26

White plaques on mucosal areas, erythema with satellite lesions on flexures

Question 27

Describe the presentation of pityriasis/tinea versicolor

Answer 27

Scaly pale brown patches on upper trunk that fail to tan on sun exposure, usually asymptomatic

Question 28

How do you manage fungal infections

Answer 28

Establish correct diagnosis - skin scrapings, hair or nail clippings (for dermatophytes), skin swabs (yeasts)
General measures - treat known preciptating factors, topical anti-fungal cream (terbinafine cream), oral antifungal agents (itraconzaole) for severe widespread infection.
Avoid the use of topical steroids - can lead to tinea incognito
Correct predisposing factors where possible