Skin

Question 1

Normal Flora

Answer 1

Coag -ve staph, s aureus, propionibacterium, corynebacterium

Question 2

HSV

Answer 2

Vesicles ulcerate and release infective particles
Lies in DRG as episomes
Triggered by infection, stress, UV light
Primary infection= painful mouth lesions
Secondary infection= peri-oral lesions
Treatment= aciclovir

Question 3

VZV

Answer 3

Shingles trigged by physical or emotional prob
Weeping vesicular rash in dermatome
Treatment= aciclovir

Question 4

Molluscum Contagiosum

Answer 4

Poxvirus
Small, raised, pearly lesions
Disappear in 6-18 months

Question 5

Orf

Answer 5

Spread by infected sheep and goats
Lumps on extremities which blister and crust
No treatment needed

Question 6

Cowpox

Answer 6

Localised and self-limiting
From cats
Blistering hand lesions

Question 7

Impetigo

Answer 7

Epidermal infection
Causes= s aureus or pyogenes
Get plaque lesions, yellow exudate and thick scabs
Treatment= mupirocin
ETA+B exotoxins may cause scolded skin or bullous impetigo

Question 8

Erysipelas

Answer 8

Dermal infection
Causes= s pyogenes
On face or shin
Demarcated inflamed lesion

Question 9

Cellulitis

Answer 9

Infection of skin and subcut
Causes= s aureus, pyogenes, pasteurella and h influenzae
Get unilateral diffuse inflamed lesion

Question 10

Anthrax

Answer 10

From imported wool and hair
Inoculates through broken skin
Malignant pustule which may become septicaemic

Question 11

Necrotising Fasciitis

Answer 11

Skin and subcut infection
Type 1= polymicrobial (gram -ve bacilli and anaerobes)
Type 2= s pyogenes
Dark necrotic spreading lesion
Need IV meropenem and clindamycin
Debridement

Question 12

Gas Gangrene

Answer 12

Cloristidium perfringens (from lower GI or anaerobic tissue)
Like NF

Question 13

Erythrasma

Answer 13

Brown scaly patches in folds of skin
Caused by corynebacterium
In DM+ obese pts
Need topical fusidic acid or macrolides

Question 14

Mycobacteria

Answer 14

Fish tank granuloma

Leprosy

Question 15

Tinea

Answer 15

Corporis= ringworm
Pedis= Feet
Cruris= Jock itch
Capitis= scalp

Question 16

Onchomycosis

Answer 16

Nail infection

Question 17

Fungal Causes

Answer 17

Tricphyton and microsporum

Need clotrimazole, terbinafine

Question 18

Psoriasis

Answer 18

Plaques on extensor surfaces
Fine and silvery
Get arthritis, CVD and skin cancer

Question 19

SLE

Answer 19

Systemic or discoid

Red scaly patches

Question 20

Bullous disease

Answer 20

Pemphigus (in epidermis, fragile blisters)

Pemphigoid (in BM)

Question 21

Dermatitis Herpetiformis

Answer 21

Small itchy blisters
Associated with coeliac
IgA deposited in papillae
Pemphigoid

Question 22

Porphyria Cutanea Tarda

Answer 22

AD or acquired (Hep C)

Porphyrin buildup causes blisters and scarring

Question 23

BCC

Answer 23

Causes= sun, radio, immunosuppression
Nodule then ulcer
Rarely mets

Question 24

SCC

Answer 24

Causes= UV, radio, chronic ulcers, drugs, immunosuppression
Ulcerated crusty nodules
Some met to lip, ear and perineum
Pre-malignant= actinic keratosis

Question 25

Melanoma

Answer 25

ABCD (asymmetry, borders uneven, colour variation, large diameter)
Causes= sun, race, FH
Breslow thickness indicates prognosis
Treatment= surgery, BRAF inhibitors

Question 26

Naevi

Answer 26

Benign melanocytes

Superficial or deep

Question 27

Lentigo Maligna

Answer 27

Slow growing, flat, pigmented patch
Proliferation of atypical melanocytes (can invade dermis and metastasise)
Due to sun damage