Lecture 4: Skin infections & infestations

Question 1

Signs of skin infection

Answer 1

Erythema
Hot
Tender
Pus (not always a sign of infection- inflammation)
Exudate
Fever

Question 2

Investigations of skin infections

Answer 2

Swab- not always indication of infections. In eczema, there can be an increased amount of staph aureus on broken skin 
FBC
ESR
U&Es
LFT
CRP
Skin biopsy
Calcium

Question 3

Common skin bacterial infections

Answer 3

Impetigo- mainly in kids

Staph aureus/ streptococcus

Cellulitis/Erysipelas

Strep pyrogens

Question 4

Differential diagnosis for skin infections

Answer 4

DVT
Venous eczema
Allergic contact dermatitis
Necrotising fasciitis

Question 5

Common fungal infections of the skin

Answer 5

Tinea - mould

Candidiasis - yeast

Question 6

Common viral infections

Answer 6

Viral warts- common in immunosuppressed patients
Can be caused by HPV virus

Molluscum contagiosum: small papules

Treatment: Potassium hydroxide

Herpes Simplex Virus:

Herpes Zoster Virus: chicken pox- cranial- caudal spread

Question 7

Common infestations of the skin

Answer 7

Scabies- caused by sarcoptes scabei (itch mite)

Common areas:
Hands, wrist ankles, belly button, nipples, toes

Crusted scabies- 1000s of mites

Question 8

Diagnosis of scabies

Answer 8

Skin scraping

Question 9

Treatment for scabies

Answer 9

Permethrin top-to- toe

Treat household to prevent reinfection