Dermatitis/Eczema Flashcards Preview

Dermatology > Dermatitis/Eczema > Flashcards

Flashcards in Dermatitis/Eczema Deck (22)
Loading flashcards...
1
Q

Describe the acute phase of eczema?

A

Papulovesicular
Erythematous (red) lesions
Oedema (spongiosis)
Ooze or scaling and crusting

2
Q

Describe the chronic phase of eczema?

A

Thickening (lichenification)

Elevated plaques

Increased scaling

3
Q

What is the pathogenesis and histology of contact allergic dermatitis?

A

Delayed (IV) reaction

Spongiotic dermatitis

4
Q

What is the pathogenesis and histology of contact irritant dermatitis?

A

Trauma eg soap water

Spongiotic dermatitis

5
Q

What is the pathogenesis and histology of atopic dermatitis?

A

Genetic and environmental factors resulting in inflammation

Spongiotic dermatitis

6
Q

What is the pathogenesis and histology of drug-allergic dermatitis?

A

Type 1 or 4 reaction

Spongiotic dermatitis and eosinophils

7
Q

What is the pathogenesis and histology of photo-induced or photosensitive dermatitis?

A

Reaction to UV light

Spongiotic dermatitis

8
Q

What is the pathogenesis and histology of lichen simplex dermatitis?

A

Physical trauma to skin- scratching

Spongiotic dermatitis and external trauma

9
Q

What is the pathogenesis and histology of stasis dermatitis?

A

Physical trauma to skin-hydrostatic pressure

Spongiotic dermatitis and extravasation of RBCs

10
Q

Describe the immunopathology of contact allergic dermatitis?

A

Langerhans cells in epidermis processes antigen (increased immunogenicity)

Processed antigen is then presented to Th cells in dermis

Sensitised Th cells migrate into lymphatics and then to regional nodes where antigen presentation is amplified

on subsequent antigen challenge specifically T cells proliferate and migrate to and infiltrate skin

11
Q

How can specific causes of contact dermatitis be identified?

A

Patch testing

12
Q

What is irritant (contact) dermatitis

A

Non specific physical irritation rather than a specific allergic reaction

13
Q

What is the distribution of atopic eczema?

A

Flexural distribution

14
Q

What is the general skin like in atopic eczema?

A

Dry

15
Q

What secondary infections are common in atopic eczema?

A

Staph aureus

16
Q

What is an eczema infection that is important to recognise early?

A

Eczema herpeticum
caused by herpes simplex virus

Will see monomorphic punched out lesions

17
Q

What are the UK diagnostic criteria for atopic eczema?

A

Itching plus 3 or more;

  • visible flexural rash
  • history of flexural rash
  • personal history of atopy
  • generally dry skin
  • onset before age 2
18
Q

Describe the treatment of eczema?

A

1) plenty of emolients
2) avoid irritants
3) topical steroids
4) treat infections
5) phototherapy- mainly UVB
6) Phototherapy- mainly UVB
7) biologic agents

19
Q

What is the most important gene in eczema?

A

Filaggrin

20
Q

discoid eczema patients are often …

A

Atopic

21
Q

What is seen in photosensitive eczema?

A

Chronic actinic dermatitis

Patients are often atopic

See cut off at exposed areas vs covered

22
Q

What is seen in pompholyx eczema?

A

Spongiotic vessels