Page 641 - Clinical Immunology_ Principles and Practice ( PDFDrive )

616 Part five Allergic Diseases

previously avoided when they are introduced under supervision. applications of topical corticosteroid to areas that had previously
Environmental control measures aimed at reducing dust mite been involved but now appear normal, with fewer relapses and less
allergen can also improve AD in sensitized patients. need for topical corticosteroids compared with treating eczema
in a reactive manner.
Psychosocial Factors In addition to their anti-inflammatory properties, topical
Recognizing and addressing sleep disturbance in patients is corticosteroids can decrease S. aureus colonization in patients
critical in managing a chronic, relapsing disease such as AD. with AD. Failure to show clinical improvement with topical
Counseling together with relaxation, behavioral modification, corticosteroids may be due to inadequate potency or amount
and biofeedback may all be of benefit, especially for patients of medication used, superinfection, steroid allergy, steroid
with habitual scratching. resistance, or, more commonly, nonadherence with the treatment
regimen, emphasizing the need for both education and alternative
Patient Education therapies.
Patients and caregivers need to be educated regarding the chronic Systemic corticosteroids, including oral prednisone, should
relapsing nature of AD, its natural history, exacerbating factors, be avoided in the management of a chronic disorder such as
and treatment options. Recognizing that normal-appearing skin AD. 13,19 Improvement observed with systemic corticosteroids may
in patients with AD is, in fact, not normal is a difficult concept be associated with flaring of AD after discontinuation. If a short
to understand but has important therapeutic implications. Patients course of oral corticosteroids is given, topical skin care should be
should be counseled about prognosis and receive appropriate intensified during the taper to suppress rebound flaring of AD.
vocational counseling. Topical corticosteroid treatment in patients with AD was
recently shown to result in improvements of the AD genomic
Hydration signature. Cytokine levels (IL-12p40, IL-13, IL-22, CCL17, CCL18,
The skin of patients with AD shows enhanced TEWL and lipid peptidase inhibitor 3 [PI3]/elafin, and S100As) were consistently
abnormalities that result in reduced water-binding capacity, reduced, with corresponding improvements in epidermal disease
10
higher TEWL, and decreased water content. Skin hydration by markers (keratin 16 and loricrin) in lesional skin from responders.
soaking the affected area or bathing and applying an occlusive Even low-potency corticosteroids can affect a broad array of
15
agent to retain absorbed water can help restore barrier function. immune and barrier responses in patients with AD.
Bathing can also remove allergens, reduce S. aureus colonization,
and act as relaxation therapy. Topical Calcineurin Inhibitors
Tacrolimus ointment (0.03% and 0.1%) and pimecrolimus cream
Moisturizers and Occlusives (1%) are nonsteroidal topical calcineurin inhibitors (TCIs)
Use of moisturizer or occlusive, especially when combined with approved for the treatment of AD. 13,14 Both drugs have proven
hydration therapy, helps restore and preserve the skin barrier effective, with a good safety profile even when used over extended
and can result in decreased need for topical corticosteroids. periods, including in infants treated with pimecrolimus. Treatment
Twice-daily emollient application has been shown to improve with TCIs is not associated with skin atrophy and may also be
barrier function and protect the skin from S. aureus proliferation useful in treating patients with steroid insensitivity. A common
17
while preserving microflora biodiversity. Patients with AD have side effect with TCIs is burning or stinging sensation of skin.
been shown to have a ceramide deficiency of the stratum corneum; Ongoing surveillance and recent reports have not shown a trend
barrier repair may be accelerated by increasing the ratio of of increased frequency of viral infections or problems with
ceramides, cholesterol, and either the essential fatty acid linoleic response to childhood vaccinations. Although there is no evidence
acid or the nonessential palmitic or stearic fatty acids. of a causal link to cancer and the use of TCIs, the US Food and
Drug Administration (FDA) issued a “box warning” because of
Corticosteroids lack of long-term safety data. The labeling states that these drugs
Corticosteroids reduce inflammation and pruritus in acute and are recommended as second-line treatments and that their use
chronic AD, acting on multiple resident and infiltrating cells, in children under the age of 2 years is currently not recommended.
primarily through suppression of inflammatory genes. Topical However, a review of epidemiological and clinical data concluded
corticosteroids have been the mainstay of conventional therapy: that the published data did not demonstrate any causal relation-
when they are appropriately used, side effects are infrequent. ship between TCI use and malignancy or lymphoma risk.
Thinning of skin, telangiectasia, bruising, hypopigmentation, Studies of proactive treatment with tacrolimus ointment in
7
acne, striae, and secondary infections may occur. The face, adults and children have shown benefit. A systematic review
particularly the eyelids, and the intertriginous areas are especially and meta-analysis of randomized clinical trials comparing TCIs
sensitive to these adverse effects. If topical corticosteroids are with topical corticosteroids for AD found that both treatment
used on the face, this can lead to perioral dermatitis, characterized classes showed similar rates of improvement and treatment
by erythema, scaling, and follicular papules and pustules around success. 20
the mouth, in the alar creases, and sometimes on the upper
lateral eyelids. Antiinfective Therapy
An important concept with translational applications is the Systemic antibiotic therapy may be necessary when a secondary
2
recognition that nonlesional, normal-appearing skin in AD infection with S. aureus is present. Recolonization after a course
shows evidence of both immunological dysregulation and skin of anti-staphylococcal therapy occurs rapidly. Maintenance
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barrier abnormalities. This observation provides a rationale antibiotic therapy should be avoided because it can result in
7
for the use of topical corticosteroids in a proactive manner. If colonization by MRSA. Bleach baths with dilute sodium hypo-
the eczema can be cleared or almost cleared but has a relapsing chlorite may reduce skin infections and improve eczema (based
course, long-term control can be maintained with twice-weekly on limited data). 13,14