Skin Infections and Infestations

Question 1

What are the types of skin infections?

Answer 1

Bacterial
Viral
Fungal

Question 2

What is the difference between cellulitis and erysipelas?

Answer 2

Cellulitis involves deep subcutaneous tissue

Erysipelas is acute cellulitis involving the dermis and upper subcutaneous tissue

Question 3

What causes Erysipelas and Cellulitis?

Answer 3

Strep pyogenes

Staph aureus

Question 4

What are some risk factors for getting cellulitis/erysipelas?

Answer 4

Immunosuppression
Wounds
Leg ulcers
Toeweb intertrigo
Minor skin injury

Question 5

How do cellulitis and erysipelas normally present?

Answer 5

Lower limb
Inflammation - swelling, red, pain, warm
Systemically unwell - fever malaise or rigors

Question 6

How does erysipelas present differently to cellulitis?

Answer 6

Well defined red raised border

Question 7

How do you manage erysipelas/cellulitis?

Answer 7

Antibiotics - fluclox/benpen

Supportive care - rest, leg elevation, sterile dressing, analgesia

Question 8

What are the complications of cellulitis and erysipelas?

Answer 8

Local necrosis
Abscess
Septicaemia

Question 9

What is staphylococcal scalded skin syndrome (SSSS)?

Answer 9

Serious skin infection seen in infancy and early childhood caused by S Aureus

Question 10

What causes SSSS?

Answer 10

Benpen resistant Staph Aureus produce circulating epidermolytic toxin that causes outer layers of skin to blister and peel

Question 11

How does SSSS present?

Answer 11

Scald like appearance followed by large flaccid bulla
Perioral crusting
Intraepidermal blistering
Painful lesions

Question 12

What are the timescales for SSSS?

Answer 12

Develop within few hours to few days

Recover within 5-7 days

Question 13

How is SSSS managed?

Answer 13

Antibiotics - fusidic acid, erythromycin or other appropriate (CHECK LOCAL GUIDELINES)
Analgesia

Question 14

When can superficial fungal infections be severe?

Answer 14

Immunocompromised individuals

Question 15

Where do fungal infections affect?

Answer 15

Skin
Nails
Hair

Question 16

What are the main groups of organisms that cause fungal infections?

Answer 16

Dermatophytes - tinea/ringworm
Yeasts - candidiasis, malassezia
Moulds - aspergillus

Question 17

How does tinea corporis present and how does it present?

Answer 17

Itchy circular lesions with clear defined raised scaly edge on the trunk and limbs

Question 18

How does tinea cruris present and how does it present?

Answer 18

Very itchy, circular lesions with clear defined raised scaly edges on the groin and nasal cleft

Question 19

What is tinea pedis and how does it present?

Answer 19

Athletes foot - moist scaling and fissuring in toewebs spreading to the sole and dorsum of the foot

Question 20

What is tinea manuum and how does it present?

Answer 20

Tinea infection of the hand - scaling and dryness in the palmar creases

Question 21

What is tinea capitis and how does it present?

Answer 21

Scalp ringworm - patches of broken hair with scaling and inflammation

Question 22

What is tinea unguium and how does it present?

Answer 22

Tinea infection of the nail - yellow discolouration with a thickened crumbly nail

Question 23

What is tinea incognito and how does it present?

Answer 23

Inappropriate treatment of tinea infection with steroids

Ill defined and less scaly lesions

Question 24

How do candidal infections present?

Answer 24

White plaques on mucosal areas

Erythema with satellite lesions in flexures

Question 25

What is pityriasis and how does it present?

Answer 25

Malassezia furfur infection

Scaly pale brown patches on upper trunk that fail to tan

Question 26

How are fungal infections investigated?

Answer 26

Skin scrapings
Hair or nail clippings
Skin swabs

Question 27

How are fungal infections managed?

Answer 27

Treat precipitating factors - immunosuppresion, moist environment

Topical antifungals - terbinafine

Oral antifungals - itraconazole if severe

Avoid use of topical steroids