ECZEMA

Dr Sami Billal - Phd, MD

Terminology

Dermatitis / Eczema

Dermatitis = Derma + titis
- Derma: refers to skin; itis: means
  - “inflamed”
  - - thus, inflamed skin
  - - other examples: arthritis, encephalitis.
Eczema = Greek term “To boil over”
Usually refers to severely inflamed dermatitis, and associated signs and symptoms (itching, sting, burning of the skin with drainage from lesions)

The terms ‘dermatitis’ and ‘eczema’ are nowadays generally regarded as the same.
The term ‘dermatitis’ to include all types of cutaneous inflammation.
So that all eczema is dermatitis, but not all dermatitis is eczema.
E.g. Dermatitis Herpetiformis (a bullous disease)

Eczemas are a group of diseases which have different types/skin manifestations
The patient usually is a known atopic or has a family history of atopy (e.g.Bronchial asthma)

1- Exogenous eczemas
- Are related to clearly defined external trigger factors
- Inherited tendencies can also play a part.
  
  Presentations
  1. Contact dermatitis
  2. Eczematous polymorphic light eruption
  3. Infective dermatitis
2- Endogenous eczema
- The eczematous condition is not a result of exogenous or external environmental factors
- Mediated by processes originating within the body.
  
  Presentations
  1. Atopic dermatitis
  2. Seborrhoeic dermatitis (dandruff & redness)
  3. Discoid eczema (very itchy coins)
  4. Palmoplantar dermatosis
  5. Pityriasis alba (small white blotches on face)

The diagnosis of eczema is usually clinically but in some cases histopathology may be needed to confirm diagnosis.

The lesions of eczema take different forms:

In the acute eczema:
1. Erythematous papules,
2. Vesicles, and
3. Oozing with crusting.; cream
In the subacute eczema:
- Lesions are reddish with scaly papules.
In the chronic eczema:
- Chronicity leads to thickened epidermis with accentuated skin markings (lichenification; hyperketatosis).; oitment steroid

Excoriations due to scratching are the commonest secondary lesions.
Conditions are usually associated with itching.
Eczema not associated with constitutional symptoms unless there is secondary bacterial infection

The histopathological features reflect a dynamic sequence of changes resulting from inflammation of the epidermis and the underlying dermal structures.
These vary with the intensity and the stage of the eczematous process

1. Spongiosis (intercellular epidermal edema) leads to stretching and rupture of the intercellular attachments, with the formation of vesicles → ACUTE ECZEMA*
1. Increased epidermal mitotic activity leads to acanthosis* → SUBACUTE ECZEMA
1. Acanthosis is associated with formation of a parakeratosis* → CHRONIC ECZEMA