• Determine whether the patient was exposed to an allergen or irritant.

• The location of the lesions is limited to the area of contact with allergen; the morphology of the lesion may suggest an external cause.

• Lesions generally appear on extensor locations—the elbows, knees, and other large joints—rather than on flexor creases.

• Patients may have a positive family history of psoriasis.

• Usually, psoriasis is less pruritic than eczema.

• Psoriatic lesions tend to be clearly demarcated from normal surrounding skin, and the scale of psoriasis is adherent and silvery. However, psoriasis may at times be clinically indistinguishable from atopic dermatitis.

• A history of exposure is important in diagnosing scabies.

• Symptoms are present in other household members.

• Characteristic distribution (e.g., in the webs between the fingers and on the flexor wrists) can mimic that of eczema.

• A positive scabies scraping is diagnostic of scabies.

• In infants, it may be difficult to distinguish atopic dermatitis from seborrheic dermatitis and at times both conditions overlap.

• Seborrheic dermatitis presents earlier in infancy (1 to 3 weeks of life) and characteristically affects the skin folds, as opposed to infantile atopic dermatitis that affects the extensor surfaces.

• The scale is greasier and has a yellow-brown color to it.

• Treat flares promptly with the appropriate strength topical corticosteroid until complete clearance, that is, the skin is no longer rough, red, or itchy.

• A daily maintenance routine is required both during periods of active flares and when disease is quiescent.

• Identification and avoidance of known and possible triggers such as extremes of temperature, outdoor and indoor allergens (i.e., dust mites, grass pollens, animal dander, molds), and irritants (i.e., sweat, harsh soaps and detergents, bubble baths, fragrances, rough synthetic fabrics, etc.).

• Communication and education about AD is paramount. The use of a Written Action Plan (see Companion eBook) and close follow-up can help ensure adherence.

Topical Therapy (see Chapter 13: Eczema and Related Disorders and “Introduction: Topical Therapy”)

• Topically applied corticosteroids to areas of active dermatitis is the mainstay of AD therapy.

• Maintenance therapy with daily gentle skin care and use of moisturizers must be a part of the treatment for all patients with AD.

• For the face and intertriginous regions (axillae and inguinal creases—areas that are “naturally” occluded), treatment should be initiated with a low-potency (class 6 or 7) ointment, such as hydrocortisone 2.5% ointment or desonide 0.05% ointment.

• Protopic ointment, 0.03% or 0.1% (tacrolimus) and Elidel 1% cream (pimecrolimus) are nonsteroidal immunomodulators that have been shown to reduce the symptoms of AD and are used as an alternative to topical steroids or as part of maintenance therapy, particularly when the eruption involves the face or intertriginous areas, such as the axillae and groin, where the long-term use of high-potency steroids is limited.

• Protopic is considered to be equivalent to a class 5 topical steroid. Protopic 0.1% is approved for the treatment of atopic dermatitis in patients >16 years and older and the 0.03% concentration is approved for patients older than 2 years.

• Elidel 1% cream is considered to be equipotent to a class 6 topical steroid.

  For information regarding the long-term safety of these agents, see “Introduction: Topical Therapy.”

• For nonintertriginous areas, treatment can be initiated with a mid-strength (class 3 or 4) cream or ointment such as mometasone 0.1% ointment (Elocon) or fluticasone 0.05% cream or 0.005% ointment (Cutivate).

• For thicker lesions, initial therapy may be with a more potent topical steroid (class 2 or 3), such as fluocinonide 0.05% cream (Lidex) ointment.

• Long-standing, lichenified eczematous lesions on the body or lesions on the hands and feet may require a superpotent agent such as clobetasol 0.05% ointment.

• Topical agents should be used until the dermatitis has cleared completely, that is, the skin is no longer rough, red, or itchy. It can be helpful to find an area on the child's skin that is free of dermatitis to show the patient and parent what clear means. Skin that is clear of dermatitis can still be hypo- or hyperpigmented.

• Wet wraps and the “soak and smear” technique are useful adjuncts for the treatment of acute severe disease, especially when lichenified and/or localized to the upper and lower extremities.

• Wet wrap treatment involves the application of a topical corticosteroid to the areas of active dermatitis over which a double layer, first moist then dry, of close-fitting cotton bandages are applied. Any type of close fitting cotton garment can be used (i.e., elastic tubular cotton bandage [Tubifast], old cotton bed sheets or t-shirts cut into wrappable strips). The cotton wraps can be left in place 3 to 24 hours with longer applications being more effective. Wet wrap treatment is effective when used for an average of 7 days.

• Soak and smear involves soaking in a bath or shower for 10 to 20 minutes followed by immediate application of the topical medication while the skin is still damp. This technique allows for moisture trapping and better penetration of the medication into the skin.

• For the child with frequent flares, especially those with a history of staphylococcal infection, “Bleach baths” with sodium hypochlorite (Clorox) (1/4 cup of household bleach in a half full bath tub or ½ cup in a full bath tub) twice weekly can be beneficial as part of the maintenance plan for atopic dermatitis.

• Oral first generation H₁ antihistamines such as diphenhydramine (Benadryl) and hydroxyzine (Atarax) probably do not reduce itching, but they are sometimes useful as inducers of sleep, a positive side effect for many patients.

• If outdoor or indoor allergens are identified as a potential exacerbating factor, daily nonsedating antihistamines such as loratidine (Claritin) or cetirizine (Zyrtec) can be beneficial.

• For patients with secondary staphylococcal infection, oral antistaphylococcal therapy with cephalexin (or other agent) is required. Bacterial cultures should always be performed before starting an oral antibiotic.

• If infection with methicillin-resistant S. aureus (MRSA) is detected or suspected, therapy with clindamycin, doxycycline (if patient is older than 8 years), or trimethoprim-sulfamethoxazole is required.

• For patients with secondary herpes simplex infection (Kaposi varicelliform eruption), oral antiviral therapy and, possibly, hospitalization may be required. A viral culture taken from the base of a fresh vesicle should be sent before initiating antiviral therapy.

• When the child continues to have severe disease such that the condition is causing significant disruption in the child's and/or family's life, more aggressive systemic therapy is warranted.

• Before resorting to systemic therapy, “soak and smear” and/or wet wraps with potent topical corticosteroids should be attempted. (See above and “Introduction: Topical Therapy.”)

• Systemic steroids should not be used for the treatment of flares of AD because of the unfavorable risk to benefit profile and the severe rebound flares of disease that often occurs upon tapering.

• Phototherapy with narrowband ultraviolet B rays and, less commonly, ultraviolet A rays, is often very effective for widespread skin involvement.

• Systemic immunosuppressive agents such as cyclosporine, mycophenolate mofetil, or azathioprine is sometimes necessary in patients with severe generalized atopic dermatitis that is refractory to topical and adjunctive therapies.

Common Myths About Atopic Dermatitis