Skin Infections / Infestations

Question 1

What are the three main types of skin infections (and examples of them)

Answer 1

Bacterial - staphyococcal and streptococcal.

Viral - HPV, herpes simplex, herpes zoster.

Fungal - tinea, yeasts.

Question 2

Erysipelas and Cellulitis: Description

Answer 2

Spreading bacterial infection of the skin.

Includes cellulitis and erysipelas.

Question 3

Difference between cellulitis and erysipelas?

Answer 3

Cellulitis involves the deep subcutaneous tissue.

Erysipelas is an acute superficial form of cellulitis and involves the dermis and upper subcutaneous tissue.

Question 4

Erysipelas and Cellulitis: Bacterial causes

Answer 4

Streptococcus pyogenes and Staphylococcus aureus.

Question 5

Erysipelas and Cellulitis: Risk factors

Answer 5

Immunosuppression, wounds, leg ulcers,

toeweb intertrigo, and minor skin injury.

Question 6

Erysipelas and Cellulitis: Presentation

Answer 6

Most common in the lower limbs.
Local signs of inflammation: swelling (tumor), erythema (rubor), warmth (calor), pain (dolor).

Systemically unwell with fever, malaise or rigors, particularly with erysipelas.

Question 7

Erysipelas and Cellulitis: Management

Answer 7

Antibiotics (e.g. flucloxacillin or benzylpenicillin).

Supportive care including rest, leg elevation, sterile dressings.

Analgesia.

Question 8

Erysipelas and Cellulitis: Complications

Answer 8

Local necrosis, abscess and septicaemia.

Question 9

Staphylococcal scalded skin syndrome: Description

Answer 9

Commonly seen in infancy and early childhood.

Causes the outer layers of skin to blister and peel, as if they’ve been doused with a hot liquid.

Question 10

Staphylococcal scalded skin syndrome: Cause

Answer 10

Production of a circulating epidermolytic toxin from phage group II, benzylpenicillin-resistant (coagulase positive) Staphylococcus aureus.

Question 11

Staphylococcal scalded skin syndrome: Presentation

Answer 11

Develops within a few hours to a few days, and may be worse over the face, neck, axillae or groins.

A scald-like skin appearance is followed by large flaccid bulla.

Perioral crusting is typical.

Intraepidermal blistering.

Lesions are very painful.

Recovery is usually within 5-7 days

Question 12

Staphylococcal scalded skin syndrome: Management

Answer 12

Antibiotics (e.g. a systemic penicillinase-resistant penicillin, fusidic acid, erythromycin or appropriate cephalosporin).

Analgesia.

Question 13

Superficial fungal infections: Description

Answer 13

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

Question 14

Superficial fungal infections: Three main groups

Answer 14

Dermatophytes - Tinea / ringworm

Yeasts - Candidiasis

Moulds - Aspergillus

Question 15

Superficial fungal infections: Tinea Corporis

Answer 15

tinea infection of the trunk and limbs:

Itchy, circular or annular lesions with a clearly defined, raised and scaly.

An edge is typical.

Question 16

Superficial fungal infections: Tinea Pedis

Answer 16

Athlete’s foot:

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

Question 17

Superficial fungal infections: Tinea Capitis

Answer 17

Scalp ringworm:

Patches of broken hair, scaling and inflammation.

Question 18

Superficial fungal infections: Management

Answer 18

Establish the correct diagnosis by skin scrapings, hair or nail clippings (for dermatophytes); skin swabs (for yeasts).

General measures: treat known precipitating factors (e.g. underlying immunosuppressive condition, moist environment)

Topical antifungal agents (e.g. terbinafine cream).

Oral antifungal agents (e.g. itraconazole) for severe, widespread, or nail infections.

Avoid the use of topical steroids – can lead to tinea incognito.