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 and vesicles which may rupture leading to oosing and crust formation. Subacute eczema: edema and vesiculation are less apparent while papules, erythema and some scales are predominant Chronic eczema: no oosing or crusting are present. The skin is dry, scaly and may be fissured. The repeated attacks of pruritic skin may lead to lichenification which means: thickening, hyperkeratosis, hyperpigmentation and increased skin markings.

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 (delayed hypersensitivity) and results from exposure of sensitized individuals to contact allergens. These sensitizers do not produce dermatitis on first exposure but after repeated exposures. It is diagnosed using the patch test; the sensitizer is applied to non affected test area of the skin of the patient. If the test is positive this area will show dermatitis.

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.

3-Adulhood stage (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 in children under 10 years) History of a generally dry skin. Personal history of other atopic disease or history of atopic disease in a first degree relative in children under 4 years. Visible flexural dermatitis (or dermatitis of cheecks/ forehead and 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 sudden attacks of crops of deep clear vesicles with no erythema develop on palms, fingers, or soles. A sensation of heat and irritation may precede the attack. It subsides spontaneously with desquamation in 2-3 weeks but is usually recurrent.

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. Mast cells are the major histamine releasing cells in the skin. Allergens react with IgE molecules which are bound to the surface of mast cells leading to mast cell degranulation and release of histamine and other mediators. This results in local increase of permeability of capillaries and venules. 2- Non allergic: direct degranulation of mast cells occurs without antigen antibody reaction due to the effect of substances like aspirin, neuropeptides, nonsteroidal anti-inflammatory drugs (NSAID), opiates, ciprofloxacin, polymixin, rifampicin and vancomycin.

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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