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Flashcards in Eczema / Dermatitis Deck (17):
1

What is eczema?

Common

disparate group of skin diseases

Unified by the presence of itch

2

What is the classification of eczema according to causative factors?

Exogenous / contact

ALLERGIC vs NON ALLERGIC (IRRITANT)
-
Allergic eczema
Irritant eczema MOST COMMON
Photodermatitis
Infective eczema

Endogenous / constitutional

ATOPIC vs NON ATOPIC
-
Atopic eczema
Seborrhoeic eczema
Discoid eczema
Pompholyx
Gravitational eczema
Asteatotic eczema
Neurodermatitis (lichen simplex chronicus)
Juvenile plantar dermatitis
Napkin dermatitis

3

What are the clinical features of acute, chronic and subacute eczema?

Acute eczema / wet eczema
-

NOT CLEARLY DEMARCATED
ITCHY
Erythema
Edema
Papules/ vesicles/blisters
Exudates ( weeping and crusting)
May spread

Chronic eczema / dry eczema
-
Same as acute eczema
Less vesicular and exudates
SCALING pigmented thickened ACANTHOSIS
Fissures
Excoriations
Lichenification

Subacute eczema
-
Features of both

4

What is the pathogenesis of eczema?

Hallmark is the activated keratinocytes

Initially stratum corneum is intact

So appears red and smooth edematous

CELL RELATED

Increased proliferation of basal cells causes epidermal thickening (ACANTHOSIS) and SCALING

CYTOKINES RELATED

Increased Cytokines cause edema, blistering and weeping and ITCHING

High levels of interleukin 1 from epidermal damage

Interleukin 8 chemotaxis causes characteristic epidermal neutrophil infiltration

Gamma interferon causes perivascular lymphocytic infiltration

5

What is the histological sequence of eczema?

Acute stage
-
Epidermal edema (SPONGIOSIS)
Vesicles
Coalesce to large blisters or rupture

Chronic stage
-
Less spongiosis and vesicles
Thick s spinosum ACANTHOSIS
Thick s corneum HYPERKERATOSIS
vasodilation with lymphocytic infiltration
LICHENIFICATION
FISSURING

6

What are the complications of eczema?

Skin related
-
Heavy bacterial colonization
Overt infection (seborrhoeic, discoid, atopic)
Dissemination (gravitational)

Quality of life related
-
Itchiness
Sleepless
Job
Sports
Sex

7

What are the DDx for eczema?

All Erythematosquamous eruptions

-
Psoriasis
Scabies
Lichen planus
Lichenoid drug eruptions
Tinea
Palmoplantar pustulosis
Angioedema
Erysipelas
Pityriases
Dermatitis herpetiformis

8

What are the investigations for eczema?

Exogenous eczema
-
Patch testing to confirm allergic contact dermatitis

Endogenous eczema
-
Patch testing for superimposed contact dermatitis in gravitational eczema

Prick testing and IgE assay for atopic eczema

Common for worsening eczema
-
Culture and scraping microscopy


9

What is the treatment for acute eczema?

Rest
Compression + antiseptic soaks
Steroid creams
NO OINTMENTS

10

What is the management for allergic contact dermatitis (type 4 hypersensitivity)?

Identify and remove contact with allergen

Topical corticosteroids

11

What are the common allergens for contact dermatitis?

METALS
-Cr Ni Co
COSMETICS
-fragrances, hair dye PPD, lanolin
PRESERVATIVE in shampoo
-formaldehyde, chlorocresol
MEDICAMENT in steroid creams, LA
-neomycin, quinoline, benzocaine
RUBBER
-mercapto mix, Thiuram mix, carba mix
PLANTS

RESINS
-epoxy resin, colophony plasters

12

What is atopic dermatitis?

Chronic
Pruritic
Dermo-epidermal inflammation
With family history of asthma, allergic rhinitis
Develops in very young age

Preventable by perinatal probiotics

13

What are the clinical features of atopic dermatitis?

Infants-
face acute eczema

Children-
flexural subacute eczema

Adults-
flexural chronic eczema

14

What are the complications of atopic dermatitis?

Secondary infection
-eczema herpeticum
-viral warts
-molluscum contagiosum
-folliculitis
-impetigo

Stunted growth

15

What is seborrhoeic eczema?

Chronic
Red scaly
Inflammatory eruption
Mainly over scalp and face
Common in adult males and infants

3 common patterns

- face scalp retroauricular
-presternal interscapular intertriginous
-flexural

16

What is discoid eczema?

Multiple
Coin shaped
Vesicular or crusted
Itchy
Plaques
Commonly in middl aged males

17

What are the common areas for lichen simplex?

Women- nape of neck

Men - legs

Both sexes- anogenital area