Dr.MOHAMED NASR

Lecturer Of Dermatology & Venereology

Zagazig University

Eczema

ECZEMA (DERMATITIS)

Inflammation of the skin

characterised by itching,

redness, scaling and clustered

papulovesicles.

Stages of eczema:

Acute eczema: there is erythema, minute papules andvesicles which may rupture leading to oosing andcrust formation.

Subacute eczema: edema and vesiculation are lessapparent while papules, erythema and some scales arepredominant

Chronic eczema: no oosing or crusting are present.The skin is dry, scaly and may be fissured. Therepeated attacks of pruritic skin may lead tolichenification which means: thickening,hyperkeratosis, hyperpigmentation and increased skinmarkings.

Classification of eczema:

A-exogenous eczema due to external triggering factors.

1-contact dermatitis

2-infective eczema (infective eczematoid dermatitis)

B-endogenous eczema due to some chemical processes originating in the body.

1-Atopic eczema

2-Seborrheic eczema

3-Discoid eczema

4-Stasis eczema

5-Asteatotic eczema

6-Pompholyx

Contact dermatitis

Allergic contact dermatitis:

This type is an immunological process (delayedhypersensitivity) and results from exposure ofsensitized individuals to contact allergens. Thesesensitizers do not produce dermatitis on first exposurebut after repeated exposures.

It is diagnosed using the patch test; the sensitizer isapplied to non affected test area of the skin of thepatient. If the test is positive this area will showdermatitis.

Irritant contact dermatitis:

This type results from exposure of the skin to

the external irritant agent with no immunologic

inflammatory reaction. It is of varied

morphology usually limited to the site of

contact.

Infective eczematoid dermatitis

It is an inflammatory reaction of the skin

adjacent to the site of oosing pyogenic

infection e.g purulent otitis or discharging

wound or ulcer.

Eczema is caused by microorganisms or their

products and clear when the organisms are

eradicated.

Atopic eczema

Atopic eczema is an itchy chronic or

chronically relapsing condition

characterised by itchy papules which

become excoriated and lichenified. It may

be associtated with other atopic

conditions in the same individual or other

family members.

Atopy: means the genetically determined or familial

tendency to develop a group of spontaneous allergic

diseases including atopic eczema, asthma, hay fever

and allergic rhinitis

Allergy: is an acquired specific alteration in the

capacity of the individual to react when exposed to

foreign substance and is manifested as augmentation

of the reaction.

Stages according to age group:

1- Infantile atopic dermatitis; occuring from 2

months to 2 years of age.

2- Childhood atopic dermatitis from 2 years to

12 years.

3- Atopic dermatitis in adolescents and adults

from 12 years onwards.

1-Infantile atopic dermatitis:

It ususally begins as erythema and

scaling of cheecks.

2-Childhood atopic dermatitis:

The classic locations are the cubital

and popliteal fossae, sides of the

neck, eyelids, flexor wrists and

ankles.

Adulhood stage -3

(atopic neurodermatitis);

It is similar to later childhood in the

form of localized erythematous scaly

papular or exudative plaques but

lesions are more dry and thick and

showing more lichenification

especially on flexures and hands.

Localised neurodermatitis

(lichen simplex chronicus):

In some cases one area is affected with

frequent severe itching and rubbing

leading to circumscribed lichenified

plaques.

Sites mostly affected are nape of neck,

hands, feet, or manifested as pruritus ani,

pruritus vulvae or scroti.

Diagnosis of atopic dermatitis:

The first important criterion is: an itchy skin condition,with scratching or rubbing.

Plus three or more of the following:

Onset below 2 years of age.

History of skin crease involvement (including cheecks inchildren under 10 years)

History of a generally dry skin.

Personal history of other atopic disease or history of atopicdisease in a first degree relative in children under 4 years.

Visible flexural dermatitis (or dermatitis of cheecks/ foreheadand outer limbs in children under 4 years).

Seborrhoeic eczema

Seborrhoea means excessive production of

sebum.

Seborrhoeic eczema is a chronic condition

with a characteristic red sharply marginated

lesions covered by greasy scales and

diagnostic distribution in the areas of rich

supply of sebaceous glands (scalp, face, upper

trunk and flexures).

Clinical picture:

Discoid (Nummular) eczema

Gravitational eczema

(venous - varicose - stasis eczema)

This eczema is secondary to venous

hypertension and stasis which is

predisposed to by prolonged

standing, ususally occurs around the

medial malleoli.

Asteatotic eczema

(winter eczema-senile eczema)

This is a type of eczema associated with

decrease in the skin surface lipids.

It may occur in old age, cases of

malnutrition, chapping, dry cold winds

and low environmental humidity and

degreasing of the skin by industrial or

domestic cleansers or solvents.

Pompholyx

This is a type of eczema in which suddenattacks of crops of deep clear vesicleswith no erythema develop on palms,fingers, or soles.

A sensation of heat and irritation mayprecede the attack.

It subsides spontaneously withdesquamation in 2-3 weeks but is usuallyrecurrent.

Treatment of eczema:

1- Correction of underlying factors e.g

Avoidance of exposure to sensitizers and solvents

Treatment of varicose veins, foci of infection, etc…

2- Broad spectrum antibiotics if secondary infection supervenes.

3- Oral antihistamines.

4- Topical cortisosteroids of appropriate strength for the patient's age and affected area twice daily for 10-21 days. Creams are used for acute and subacute cases and ointments for dry chronic cases.

5- Topical emolients as vaseline for dry skin and in chronic cases.

6- Topical immunomodulators: tacrolimus ointment 0.03% or pemicrolimus 1% cream twice daily.

7- Short course of systemic steroids in acute, severe and wide spread cases.

8- Ultraviolet rays therapy with PUVA and narrowband UVB (NBUVB).

URTICARIA AND ANGIOEDEMA

Urticaria are attacks of itchy well demarcated

reddish evanescent swellings of the skin

(wheals=hives) and are usually associated with

pruritus or burning sensation.

Angioedema is characterised by swellings of deep

dermal and subcutaneous/submucosal tissues.

Swellings are painful rather than itchy, poorly defined

and pale or normal skin coloured.

Acute if it has been present continuously or

intermittenly for less than 6 weeks.

Chronic if it has been present for at least 6

weeks or more. When no underlying cause is

identified it is termed chronic idiopathic

urticaria.

Pathophysiology:

1- Allergic: histamine is an important mediator in urticaria. Mastcells are the major histamine releasing cells in the skin.Allergens react with IgE molecules which are bound to thesurface of mast cells leading to mast cell degranulation andrelease of histamine and other mediators. This results in localincrease of permeability of capillaries and venules.

2- Non allergic: direct degranulation of mast cells occurs withoutantigen antibody reaction due to the effect of substances likeaspirin, neuropeptides, nonsteroidal anti-inflammatory drugs(NSAID), opiates, ciprofloxacin, polymixin, rifampicin andvancomycin.

Causes of urticaria:

1- Food: food additives or preservatives, fishes, banana, nuts, eggs, chocolate and cheese.

2- Drugs: aspirin, NSAIDs, antibiotics eg; penicillin..etc

3- Inhalants: pollens, dust or animal fur

4- Intestinal parasites

5- Stress

6- Septic foci eg; in teeth, tonsils or urinary tract

7- Physical causes: heat, cold, water, vibration, sunlight or pressure

8- Cholinergic urticaria: is a specific type in which small weals occur in association with sweating due to heat or emotional stress

9- Insect bites or stings

10- Contact urticaria eg; occupational exposure

11- Medical causes: like hepattitis, obstructive jaundice and Helicobacter pylori infection

12- Serum sickness

Treatment:

1-Treatment of the cause if possible.

2- AntiH1 antihistamines are the first line of treatment:

a- traditional classic antiH1 eg; chlorpheneramine maleate, diphenhydramine, and hydroxizine

b- non sedating antiH1: cetrizine hydrochloride, loratadine, fexofenadine, desloratadine and acrivastine

3- AntiH2 antihistamines may be needed in addition to antiH1 eg; cimetidine and ranitidine

4- Systemic steroids in severe cases; prednisolone 0.5 to 1mg /kg.

5- Locally: calamine lotion is used for soothing the sensation of pruritus.

6- In angioedema: distressing the respiratory passages from oropharyngeal-laryngeal edema; epinephrine (adrenaline) in 1/1000 solution is the first line of management. It is given subcutaneously in a dose 0.2-0.5 ml.

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