Dermatitis

Question 1

Acute phase of eczema

Answer 1

Papiculovesicular
Erythematous lesions
Oedema (spongiosis)
Ooze or scaling and crusting

Question 2

Chronic phase of eczema

Answer 2

Thickening (lichenification)
Elevated plaques
Increasing scaly

Question 3

Rash in eczema

Answer 3

Itchy, ill-defined erythematous scaly rash

Question 4

What type of hypersensitivity is contact allergic dermatitis?

Answer 4

Type IV hypersensitivity

Question 5

What can contact allergic dermatitis occur in response to?

Answer 5

Chemicals, topical therapies, nickel, plants

Question 6

Immunopathology of contact allergic dermatitis

Answer 6

Langerhans cells in epidermis process antigen
Processed antigen is presented to Th cells in dermis
Sensitised Th cells migrate into lymphatics and then to regional lymph nodes where antigen presentation is amplified
On subsequent antigen challenge, sensitised T cells proliferate and migrate to and infiltrate skin leading to dermatitis

Question 7

What can be used to identify specific substances causing contact dermatitis?

Answer 7

Patch testing

Question 8

Describe irritant dermatitis

Answer 8

Non-specific physical irritation rather than a specific allergic reaction

Question 9

Examples of things that can cause irritant dermatitis

Answer 9

Soap, detergent, cleaning products, water, oil

Question 10

Examples of irritant dermatitis

Answer 10

Nappy rash and lip lick dermatitis

Question 11

Describe atopic eczema

Answer 11

Ill-defined erythema and scaling and general dry skin with generally flexural distribution. Pruritus is a common symptom and atopic eczema is often associated with other atopic disease

Question 12

Impact of atopic eczema

Answer 12

Pruritus can lead to sleep disturbance which can lead to neurocognitive impairment. There is an effect on the whole family

Question 13

Other atopic diseases that can be associated with atopic eczema

Answer 13

Atopic asthma, food allergy, allergic rhinitis

Question 14

Chronic changes that can occur with atopic eczema

Answer 14

Lichenification, excoriation, secondary infection

Question 15

Which virus causes eczema herpeticum?

Answer 15

Herpes simplex virus

Question 16

Describe the lesions in eczema herpeticum

Answer 16

Monomorphic punched out lesions

Question 17

True or false: eczema herpeticum is a medical emergency

Answer 17

True

Question 18

UK diagnostic criteria for atopic eczema

Answer 18

Itching plus 3 or more:

• Visible flexural rash
• History of flexural rash
• Personal history of atopy (or first degree relative if <4 y/o
• Generally dry skin
• Onset before 2 years of age

Question 19

Treatment of eczema

Answer 19

Emollients
Avoid irritants including shower gels and soaps
Topical steroids
Treat infection
Phototherapy - mainly UVB
Systemic immunosuppression

Question 20

Describe discoid eczema

Answer 20

Often atopic, very well defined in discs, often infected

Question 21

True or false: photosensitive eczema is often atopic

Answer 21

True

Question 22

Stasis eczema can be secondary to what?

Answer 22

Hydrostatic pressure
Oedema
Red cell extravasation

Question 23

Which areas does seborrheic eczema usually effect?

Answer 23

Nose, eyebrows, ears and scalp

Question 24

When should patients with eczema be referred to specialists?

Answer 24

Failure to respond to moderately potent/potent steroids
Patient is systemically unwell
Sleep problems/psychological aspect