Skin Infections/Infestations

Question 1

What is Erysipelas?

Answer 1

An acute superficial form of cellulitis and involves the dermis and upper subcutaneous tissue

Question 2

What is Cellulitis?

Answer 2

Cellulitis involves the deep subcutaneous tissue

Question 3

What are causes of Erysipelas and Cellulitis?

Answer 3

• Streptococcus pyogenes
• Staphylococcus aureus

Question 4

What are risk factors of Erysipelas and Cellulitis?

Answer 4

Risk factors include

• Immunosuppression
• Wounds
• Leg ulcers
• Toeweb intertrigo
• Minor skin injury

Question 5

How does Erysipelas and Cellulitis present?

Answer 5

Most common in the lower limbs

• Local signs of inflammation: Swelling (tumor), Erythema (rubor), Warmth (calor), Pain (dolor); may be associated with lymphangitis
• Systemically: Unwell with fever, Malaise or Rigors, particularly with erysipelas

Erysipelas is distinguished from cellulitis by a well-defined, red

raised border

Question 6

How does Cellulitis differ in presentation to Erysipelas?

Answer 6

Erysipelas is distinguished from cellulitis by a well-defined, red raised border

Question 7

What are complications of Erysipelas and Cellulitis?

Answer 7

• Local necrosis
• Abscess
• Septicaemia

Question 8

What is the management of Erysipelas and Cellulitis?

Answer 8

• Antibiotics (e.g. flucloxacillin or benzylpenicillin)
• Supportive care including rest, leg elevation, sterile dressings and analgesia

Question 9

What causes Staphylococcal scalded skin syndrome?

Answer 9

• Commonly seen in infancy and early childhood
• Production of a circulating epidermolytic toxin from phage groupII, benzylpenicillin-resistant (coagulase positive) staphylococci

Question 10

How does Staphylococcal scalded skin syndrome present?

Answer 10

• 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
• 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 11

How is Staphylococcal scalded skin syndrome managed?

Answer 11

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

Question 12

What is this?

Answer 12

Staphylococcal scalded skin syndrome

Question 13

What are superficial fungal infections?

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

What is the cause of Superficial fungal infections?

Answer 14

• Dermatophytes (tinea/ringworm)
• Yeasts (e.g. candidiasis, malassezia)
• Moulds (e.g. aspergillus)

Question 15

What is Tinea Corporis?

Answer 15

Tinea infection of the trunk and limbs

• Present with itchy, circular or annular lesions with a clearly defined, raised and scaly edge is typical

Question 16

What is Tinea Cruris?

Answer 16

Tinea infection of the groin and natal cleft

• Presents with very itchy groin and natal cleft, similar to tinea corporis

Question 17

What is Tinea Pedis?

Answer 17

Athlete’s foot

• Present as moist scaling and fissuring in toewebs, spreading to the sole and dorsal aspect of the foot

Question 18

What is Tinea Manuum?

Answer 18

Tinea infection of the hand

• Presents with scaling and dryness in the palmar creases

Question 19

What is Tinea Capitis?

Answer 19

Scalp ringworm

• Presents with patches of broken hair, scaling and inflammation

Question 20

What is Tinea Ungulum?

Answer 20

Tinea infection of the nail

• Presents with a yellow discolouration, thickened and crumbly nail

Question 21

What is Tinea incognito?

Answer 21

Inappropriate treatment of tinea infection with topical or systemic corticosteroids

• Presents with Ill-defined and less scaly lesions

Question 22

What is Skin Candidiasis?

Answer 22

Candidal skin infection

• Presents with white plaques on mucosal areas, erythema with satellite lesions in flexures

Question 23

What is Pityriasis/Tinea versicolor?

Answer 23

Infection with Malassezia furfur

• Presents with scaly pale brown patches on upper trunk that fail to tan on sun exposure, usually asymptomatic

Question 24

How are fungal infections managed?

Answer 24

• 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
• Correct predisposing factors where possible (e.g. moist environment, underlying immunosuppression)