25. Dermatology

Question 1

# Fill in the blank 
label 1

Answer 1

Unlabel 1

Question 2

What is a squamous cell carcinoma?

Answer 2

A locally invading cancer of keratinocytes of the epidermis. Second most common skin cancer.

RF - UV light, FHx, light skin, actinic keratosis

Question 3

What is a basal cell carcinoma?

Answer 3

Cancer of keratinocytes in the epidermis of stratum basal. This doesn’t often metastasise and is most common skin cancer

RF - UV light, FHx, light skin

Question 4

What are the four subtypes of a BCC?

Answer 4

1. Nodular - most common, rolled edges and central ulcer
2. Superficial - flat
3. Morpheic - yellow, waxy, scar-like
4. Pigmented - dense colour, appears like melanoma

Question 5

What’s the ABCDE of lesions?

Answer 5

Asymmetry
Border
Colour
Diameter
Evolution

Question 6

What is a malignant melanoma?

Answer 6

Cancer of melanocytes in epidermis. Most deadly skin cancer. It’s irregular, pigmented, may bleed, itch, ulcerate or crust.

Question 7

How might we investigate a skin cancer?

Answer 7

Bedside - dermatoscope
Bloods - calcium, ALP, LFTs for mets
Imaging - CT/MRI/PET
Skin biopsy - breslow thickness

Question 8

How would we manage SCC, BCC and melanomas?

Answer 8

SCC - cryotherapy, surgery, radiotherapy
BCC - surgery
Melanoma - surgery with lymph node biopsy, systemic therapy (nivolumab) and met treatment

Question 9

What is eczema?

Answer 9

Inflammatory skin condition. Often associated with atopy and the filaggrin gene mutation.

Skin is dry, itchy, erythematous. Can have lichenification and distributed around flexure.

Question 10

What are the six main types of eczema?

Answer 10

Atopic
Contact dermatitis
Discoid dermatitis - older people, coin-shaped
Seborrhoeic dermatitis - yellow, greasy, scaly rash
Dyshidrotic - itchy/painful blisters over hands and feet
Eczema herpeticum - medical emergency from HSV-1

Question 11

What is psoriasis?

Answer 11

Auto-immune condition caused by hyperproliferation of keratinocytes.

Purple, silvery plaques that are dry and flakey, itchy or painful.

Question 12

Signs of psoriasis not on skin?

Answer 12

Nail - onchyolysis, pitting, subungual hyperkeratosis
Psoriatic arthritis

Question 13

Five subtypes of psoriasis?

Answer 13

Plaque psoriasis (most common)
Pustular
Guttate - raindrop plaques often post-strep
Flexural psoriasis
Erythrodermic - systemic body redness and inflammation

Question 14

How would we investigate inflammatory skin conditions? (eczema and psoriasis)

Answer 14

Usually clinical diagnosis

Can do -
Skin patching for contact dermatitis
IgE for atopy
Skin biopsy

Question 15

How would we manage psoriasis?

Answer 15

Plaque - topic hydrocortisone
Pustular - acitretin and then ciclosporin
Gutate - Phototherapy, then ciclosporin, then methotrexate

Question 16

How would we manage eczema?

Answer 16

Acute - emollients with topical corticosteroids
Chronic/relapsing - emollients with low potency corticosteroids

Question 17

What is urticaria?

Answer 17

Skin lesions developing rapidly from hypersensitivity reactions to a specific trigger.

Lesion is blanching, non-painful and erythematous

Question 18

How would we investigate and manage urticaria?

Answer 18

FBC, ESR, CRP
Identify trigger

Treat trigger
Antihistamines
Oral corticosteroids if severe

Question 19

What are cellulitis and erysipelas?

Answer 19

Bacterial infections of skin, often strep pyogenes or staph aureus.
Acute onset inflammation.

Question 20

How does cellulitis present?

Answer 20

On dermis and subcut tissue, is patchy. Sepsis is common, rarely systemic symptoms.

Question 21

How does erysipelas present?

Answer 21

Epidermal, well-demarcated. Systemic symptoms of fevers and rigors. Rarely septic.

Question 22

Investigations for a skin infection? (e.g. cellulitis)

Answer 22

Usually a clinical diagnosis

Skin swab
FBC, CRP, blood cultures
CT/MRI (if orbital cellulitis)

Question 23

How would we manage a skin infection? (cellulitis or erysipelas)

Answer 23

Ensure it isn’t growing
Oral fluids and pain relief

Oral ABx
IV ABx if severe or near eyes

Admit if septic (high HR, RR or low BP) or if confused (GCS)

Question 24

What is necrotising fasciitis?

Answer 24

Life-threatening subcutaneous soft tissue infection. (can start out as cellulitis)

Question 25

Signs and symptoms of necrotising fasciitis?

Answer 25

Severe pain or anaesthesia over site.
Systemic signs of infection: fever, palpitations, tachycardia, tachypnoea.
Lesion is warm with oedema, erythematous and may turn violet.

Question 26

Investigations and management of necrotising fasciitis?

Answer 26

Clinical diagnosis

Surgical exploration and debridement with blood and tissue cultures AFTER
IV empirical antibiotics and supportive care.

Question 27

What is erythema multiforme?

Answer 27

Inflammation of skin and mucous membranes, typically type IV hypersensitivity. Prodrome fever, aches, itchiness, pain etc.

Target lesions with central vesicle/crust. Ring of pallor and erythema.

Question 28

What might cause erythema multiforme?

Answer 28

Infection - commonly HSV, mycoplasma, HIV
Drug reactions - sulphonamides (ABx)

Question 29

How would we treat erythema multiforme?

Answer 29

Minor - topical emollient with topical/oral corticosteroids
Major - topical emollient with oral/IV corticosteroids

Question 30

What is molluscum contagiosum?

Answer 30

Skin infection due to pox virus.
Lesions are smooth papules, painless but often itchy, transmitted through close contact.

Clinical diagnosis.