Eczema & dermatitis

The terms eczema and dermatitis are used interchangeably to describe a range of inflammatory skin conditions of which the principal symptoms are dryness, erythema and itch, often with weeping and crusting.

It has become conventional to apply the term eczema to conditions with an endogenous cause in atopic individuals and the term dermatitis to reactions to external agents.

ATOPIC ECZEMA

Atopic eczema is a chronic fluctuating inflammatory condition of the skin with no known cause, although there is often a genetic link and a family history of allergic sensitivity. Incidence of atopic dermatitis is about 3-10% of the population, and appears to be increasing as a result of an increase in irritants and pollutants in the home.

About 50% of patients develop the condition within the first year of life. By 5 years old, 87% of sufferers have developed their condition. Less than 2% develop eczema after the age of 20 years.

The condition improves with age -- about 50% of cases resolve themselves by the time the patient reaches 13 years old and few cases persist beyond the age of 30 years.

CONTACT DERMATITIS

There are two types of contact dermatitis -- irritant and allergic.

Irritant dermis

Irritant dermatitis is the result of direct damage to the skin by a provoking agent on first exposure to a strong irritant, or repeated exposure to a milder one.

Once the outer keratin layer of the skin has been damaged, irritant substances are able to pass into the cells of the epidermis and cause an inflammatory reaction. Irritant agents include:

• detergents and household cleaning materials

• hair tints and perming solutions

• building and DIY materials

• gardening products.

The condition may be chronic, eg from continual wetting of the skin.

Allergic dermatitis

Allergic dermatitis is the result of hypersensitivity to a sensitising agent. It can occur after just a couple of exposures or may take several years of repeated exposure to develop. Once established, sensitivity usually remains for life. Sensitising agents include:

• rubber in household gloves and footwear

• nickel in costume jewelry, zips, bra clips and belt buckles

• resins in glues

• ingredients of cosmetics and toiletries

• some plants

• paints and cement.

What are the symptoms of eczema? ATOPIC ECZEMA

• There is a dry, scaly, often erythematous rash

• Typical distribution is inside elbows, behind knees, on cheeks, forehead and outer limbs

• It is very itchy; patients tend to scratch and excoriate the skin, opening the way for bacterial infection. Continued scratching can lead to lichenification (hardened and leathery skin)

• There is usually a family history of atopic disease

• Patients may have other atopic disease, eg asthma, hayfever

• The disease may be chronic, with periodic acute exacerbations.

• If chronic, the skin will be dry, fissured and painful, and may bleed

IRRITANT CONTACT DERMATITIS Acute exposure

• Itchy, inflamed skin, usually red and swollen, and papular with vesicles

• Lesions develop rapidly within 6-12 hours of contact

• Distant body sites are not commonly affected

• Recovery may be rapid if there is no further contact with the irritant
Chronic exposure

• A dry, irritable, red, scaly eruption

ALLERGIC CONTACT DERMATITIS

• History of contact with the allergen

• In the acute or early stages, the skin is inflamed and itchy with weeping and vesiculation

• In the chronic stages there is dryness and scaling, with fissuring areas

• Often there is a sharp cut-off point defined by the area of contact, but in long-standing dermatitis irritation may become generalised and spread to areas not in contact with the allergen.
Could it be more serious?

SYMPTOMS AND CIRCUMSTANCES FOR REFERRAL

• If the condition is severe, with badly fissured or cracked skin and bleeding

• If there is evidence of infection (weeping skin)

• Failure of OTC treatment

• Contact dermatitis with no identifiable cause

• Duration longer than two weeks

OTC treatments ATOPIC ECZEMA Moisturisers and emollients

• Moisturisers and emollients should be used regularly and liberally to keep the skin hydrated. Although time-consuming and messy to use, they provide considerable benefit and help prevent flare-ups

• A wide range is available (see BNF 48, pp. 554-7). Eczema is a dry skin condition, and in general the greasier the preparation the more moisture-retaining ability it confers on the skin

• Greasier preparations are better for dry, cracked and thickened skin, and should be applied thickly overnight

• Thinner creams and lotions rub in more easily and are more cosmetically acceptable, but to be effective need to be reapplied several times a day

• Emollients should also be used in the bath and as soap substitutes. Emollient topical applications are most effective if applied immediately after a bath, after the skin has been patted dry but still retains some moisture.

Corticosteroid creams

• Corticosteroid creams: hydrocortisone (several brands available) and clobetasone (Eumovate Eczema and Dermatitis Cream) are licensed for pharmacy sale for short-term treatment of mild to moderate eczema. Clobetasone is more potent than hydrocortisone and more effective for flare-ups. Both are applied sparingly to the affected area(s) twice daily until the condition resolves, for up to a maximum of 7 days

• There are several licensing restrictions on the use of OTC corticosteroids

• Application is restricted to 'small areas' only

• They may be used on the face, or in the eyes or anogenital areas

• They may not be used on ulcerated, broken or weeping skin, or with occlusive dressings

• They are contraindicated in pregnancy and during lactation

• Hydrocortisone is not licensed for use in children under 10 years of age

• Clobetasone may be used in children under 12 years of age, on the advice of a doctor

Oral antihistamines

• Severe pruritus (itching) in children, particularly at night, can be treated with oral antihistamines. Chlorphenamine syrup is licensed for use in patients from 12 months old, promethazine syrup in patients from 2 years old. They can cause drowsiness, although this may be a benefit.

IRRITANT CONTACT DERMATITIS Topical corticosteroids

• Use topical corticosteroids if necessary. (They may be used on the earlobes for dermatitis caused by costume jewelry earrings, as this area is not classified as part of the face).

• Use emollients to replace the lipid barrier of the skin.

ALLERGIC CONTACT DERMATITIS Topical corticosteroids

• Use topical corticosteroids if necessary. Use non-sedating oral antihistamines (acrivastine, cetirizine, loratidine) if necessary -- these do not normally cause drowsiness. Sedating antihistamines (chlorphenamine, promethazine) can be used for night relief of irritable dermatitis. There are some restrictions and cautions associated with use of sedating antihistamines:

• Alcohol must be avoided while taking them

• As they tend to cause drowsiness, they should be used with caution if the patient needs to drive or operate machinery

• They should be used with caution in patients with prostatic hypertrophy, epilepsy, glaucoma, hepatic disease and CNS depression

• They potentiate the effects of drugs with sedative or antimuscarinic actions, including:

-- benzhexol and orphenadrine (both used for Parkinson's disease)

-- benzodiazepines and tricyclic antidepressants.

What treatment is available?

FIRST-LINE THERAPY

• Moisturisers and emollients (all available OTC)

• Corticosteroid creams (some available OTC)

• Oral antihistamines (most available OTC)

SECOND-LINE THERAPY

• Topical immunosuppressants (tacrolimus, pimecrolimus)

• Oral immunosuppressants (corticosteroids, others -- eg ciclosoprin, azathioprine, in specialist secondary care only)

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Last updated Jan 4/07