Skin infections/infestations

Question 1

What is erysipelas/cellulitis?

Answer 1

Both are spreading bacterial infections of the skin
Cellulitis involves the deep subcutaneous tissue
Erysipelas is an acute superficial form of cellulitis and involves the dermis and upper subcutaneous tissue

Question 2

What are the causes of erysipelas/cellulitis?

Answer 2

strep pyogenes

and staph aureus

Question 3

What are the risk factors for erysipelas/cellulitis?

Answer 3

Immunosuppression 
Wounds 
Leg ulcers 
Toeweb intertrigo (burning sensation between toes)
Minor skin surgery

Question 4

How does erysipelas/cellulitis present?

Answer 4

Swelling (tumor) 
Erythema (rubor) 
Warmth (Calor) 
Pain (Dolor) 
May be associated with lymmphangitis (inflammation of the lymphatic system)

Question 5

How is erysipelas distinguished from cellulitis?

Answer 5

Erysipelas will have a well defined, red raised border

Question 6

What is the management of cellulitis?

Answer 6

Antibiotics- flucloxacillin or benzylpenicillin

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

Question 7

What are the complications of erysipelas/cellulitis?

Answer 7

Local necrosis
Abscess
Septicaemia

Question 8

What is the cause of staphylococcal scalded skin syndrome?

Answer 8

Production of a circulating epidermolytic toxin from phage group 2, benzylpenicillin- resistant (coagulase positive) staphylococci

Question 9

What is the presentation of staphylococcal scalded skin syndrome?

Answer 9

Develops within a few hours to a few days, may be worse over the face, neck, axillae, or groins
A scald like skin appearance will be followed by a large flaccid bulla
Perioral crusting is typical
There is intraepidermal blistering in this condition
Lesions are very painful
Sometimes the eruption is more localised
Recovery is usually within 5-7 days

Question 10

How would you treat staphylococcal scalded skin syndrome?

Answer 10

Abx- flucloxacillin, erythromycin or an appropriate cephalosporin
Analgesia

Question 11

What is a superficial fungal infection?

Answer 11

A common and mild infection of the superficial layers of the skin, nails and hair
Can be severe in immunocompromised individuals

Question 12

What are the three main groups of superficial fungal infection?

Answer 12

Yeasts (candidiasis)
Dermatophytes (tinea/ringworm)
Moulds (aspergillus)

Question 13

What is the general presentation of a fungal infection?

Answer 13

Presentation varies with the site of the infection, it is usually unilateral and itchy.

Question 14

What is tinea corporis?

Answer 14

This is tinea infection of the trunk and the limbs

It presents with itchy, circular or annular lesions with a clearly defined raised and scaly edges is typical

Question 15

What is tinea cruris?

Answer 15

Tinea infection of the groin and natal cleft

Very itchy and similar to tinea corporis

Question 16

What is tinea pedis?

Answer 16

Also known as athlete’s foot

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

Question 17

What is tinea manuum?

Answer 17

Tinea infection of the hand

Scaling and dryness in the palmar creases

Question 18

What is tinea capitis?

Answer 18

This is scalp ringworm

You get patches of broken hair, scaling and inflammation

Question 19

What is tinea unguium?

Answer 19

This is tinea infection of the nail- yellow discolouration thickened and crumbly nail

Question 20

What is tinea incognito?

Answer 20

This is inappropriate treatment of tinea infection with topical or systemic corticosteroids
You get ill defined and less scaly lesions

Question 21

What is candidiasis? How does it present?

Answer 21

This is a candidal skin infection (yeast)

Causes white plaques on mucosal areas, erythema with satellitle lesions in flexures

Question 22

How does pityriasis/tinea versicolor present?

Answer 22

This is an infection with Malassezia furfur

Presents as scaly pale brown patches on the upper trunk that fail to tan on sun exposure, they are usually asymptomatic.

Question 23

What is the management of fungal infections?

Answer 23

You have to establish the correct diagnosis by skin scrapings, hair or nail clippings (for dermatophytes) or skin swabs (for yeasts)

Topical antifungal agents eg: terbinafine cream

Oral antifungals: itraconazole

Correct predisposing factors where possible- moist environment, underlying immunosuppression