Download atopic dermatitis

SEPTEMBER 2014
A
ATOPIC DERMATITIS
topic dermatitis, also known as atopic eczema, is
a chronic inflammatory skin condition affecting
some older people. The condition commonly
affects children and is less common in adults affecting
only 1-3% of adults. Atopic dermatitis in adults usually
exists for years, compromising sleep and quality of life.
Older people are prone to certain adverse drug effects
of products used to treat the condition.
although it can still occur especially in lower
extremities.
Numerous changes occur in ageing skin, which may
predispose to dermatitis and itching. The epidermal
thickness of the skin is reduced with ageing. The
dermis undergoes atrophy with a reduction in
connective tissue substances such as blood vessels,
nerve endings, sweat and sebaceous glands. Drying
of the skin can be a particular problem. Older people
with thin, fragile skin may have increased absorption
of corticosteroids from creams and ointments.
The most important aspect of treatment of atopic
dermatitis is liberal use of emollients and moisturisers.
Moisturisers improve the skin’s barrier function and
reduce water loss from the skin, leading to a reduction
of itching, pruritus and risks of infection. They also
increase the efficacy of topical corticosteroids,
reducing the amount required and the potential for
adverse effects.
Symptoms
Common symptoms include:
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Itching
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Redness
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Scaling
Acute atopic dermatitis presents with a vesicular,
weeping, crusting eruption. Subacute dermatitis
presents with dry, scaly, red small rounded bumps
(papules) and plaques. When the condition becomes
chronic, lichenification can occur from repeated
scratching. Lichenification refers to a thickening of the
epidermis seen with exaggeration of normal skin lines.
Causes
Factors contributing to the skin condition may be
endogenous or exogenous. Endogenous factors are
mediated by changes in the skin immune system such
as atopy. Exogenous factors include contact allergens,
ambient temperature, humidity and sunlight, and
psychological stress.
It is not unusual for women to develop eczema for the
first time after menopause. Calcium channel blockers
can cause eczema. Changes in immunity for numerous
reasons may contribute to atopic dermatitis.
Contact dermatitis is less common in the elderly,
Treatment
Before starting treatment, any irritants should be
identified and avoided. Irritants include soaps,
detergents, bubble bath, and abrasive clothing.
Moisturisers
Emollients with high oil content and low water content
are recommended.
Moisturisers should be applied liberally at least twice
a day. Emollients should be smoothed gently on to the
skin, as the act of rubbing will stimulate circulation,
generate heat and make the skin feel itchier. The
emollient should be applied smoothly in the general
direction of hair growth to prevent accumulation
at hair bases which may predispose to folliculitis
(infection of the hair follicles in the skin), particularly
when greasy ointments are used.
Application after a warm shower is best while the skin
is still moist. Use of moisturisers should be continued
after symptoms of dryness and itchiness have
resolved. Regular emollient use can reduce the need
for topical corticosteroid use and improved symptoms.
Moisturisers containing sodium lauryl sulfate such
as aqueous cream or emulsifying ointment should
be avoided as they may worsen eczema by causing
irritation and damaging the skin barrier.
Topical steroids
Topical corticosteroids may be needed if the skin is
inflamed. Excessive scratching can lead to cellulitis, a
bacterial infection of the skin.
ATOPIC DERMATITIS
Fingertip units can be used to estimate the amount
of corticosteroid to be applied. A fingertip unit is the
amount of cream or ointment applied from the distal
skin-crease to the tip of the index finger. One fingertip
unit (approximately 500 mg) is sufficient to cover a
hand and fingers (front and back). See www.amh.net.
au/downloads/fingertipunits.pdf for a fact sheet on
fingertip units.
Ointments are generally more effective than creams,
although they may be less preferred by many as they
can be greasy and difficult to wash off. Creams tend to
be cooling and lubricating, often preferred by patients.
Lotions and solutions tend to be drying and cooling
and can be applied without friction on fragile skin.
Preservatives in cream may cause sensitisation.
The potency of the topical corticosteroid should
be based of the severity, area and location and the
patient’s age. Mild potency corticosteroids (e.g.
hydrocortisone 0.5-1%) are recommended for the face,
neck, groin and flexures. Moderate potency products
can be used for mild-to-moderate atopic dermatitis.
These include betamethasone valerate 0.02% and
0.05% cream and ointment, clobetasone 0.05% cream,
desonide 0.05% lotion, and triamcinolone 0.02%
cream and ointment. Potent topical corticosteroids
should only be used for short-term management
of severe inflammatory eczema. Potent products
include betamethasone diproprionate 0.05%,
betamethasone valerate 0.1%, mometasone 0.1% and
methylprednisolone 0.1%.
To reduce adverse effects of topical corticosteroids
they should only be used for the shortest time
possible to control symptoms, usually 2 weeks or less.
After acute symptoms have resolved, the resident
should use emollients and moisturisers only, still
avoiding all soap products. If flare-ups are frequent,
corticosteroids can be used 2 or 3 times a week or on 2
consecutive days per week to maintain remission.
Adverse effects
Adverse effects of topical corticosteroids include skin
atrophy, delayed wound healing, loss of pigmentation,
striae, telangiectasia (broken capillaries) and folliculitis
(infection of the hair follicles in the skin).
Other treatments
Scalp involvement with seborrheic dermatitis
can be treated with tar-based products as well as
shampoos containing selenium sulphide, miconazole,
ketoconazole or ciclopirox. Products containing
salicylic acid and/or sulphur may be used to reduce
scale.
Sedating oral antihistamines may be useful for
residents with sleep disturbances due to excessive
itching.
Phototherapy and topical calcineurin inhibitors
eg, pimecrolimus can be prescribed for short-term
treatment and intermittent long-term management of
atopic dermatitis. Pimecrolimus can be used on facial,
neck or eyelid areas as it does not cause skin atrophy;
although it is less effective than moderate or potent
topical corticosteroid preparations.
There is no evidence that probiotics, zinc, vitamin E or
fish oils are effective in the prevention or treatment of
atopic dermatitis.
Summary
Emollients and moisturisers are considered as firstline agents in the management of atopic dermatitis or
eczema. They are also advised as adjuvant to topical
anti-inflammatory treatments such as corticosteroids
and calcineurin inhibitors, as they have steroid-sparing
properties. Topical corticosteroids can be used to
manage flare-ups of eczema. Potency should be
tailored of the severity of the disease and used for the
shortest time possible to control symptoms. Residents
with frequent flare-ups or severe atopic dermatitis
may require referral to a dermatologist.
References
Dermatology 2007;214(1):61-67.
American Family Physician 2012;86(1):35-42.