Atopic Dermatitis - Anti-Inflammatory Treatment

Topical corticosteroids are the first-line treatment for AD. They are available in potencies ranging from extremely high (class I) to low (class VII). In general, a corticosteroid formulated in an ointment base is more potent than one in a cream or lotion base. Ointment-based preparations are also more occlusive and have the fewest number of additives.

They provide better delivery of the medication and decrease evaporative loss. Creambased preparations, however, may be better tolerated during conditions of excessive heat or humidity. Although lotions are easier to apply, they may contribute to irritation and xerosis. Solutions are useful for the scalp.

Although their high alcohol content can be irritating and drying. Alotion-based corticosteroid may be better tolerated. The choice of topical corticosteroid potency depends on the severity and distribution of AD. Although using the least potent corticosteroid is typically a good rule to follow.

This approach should be balanced by the possibility that treatment with a preparation that is too weak may result in persistence or worsening of AD, which can in turn result in decreased adherence or the need for high-potency topical or systemic corticosteroids.

A stepped approach starting with a mid-potency preparation (except for eczema involving the face, axillae, or groin) and, with clinical improvement, use of a lower-potency preparation may be a more effective strategy. High-potency corticosteroids may be needed for severe hand and foot eczema.

In general, use of topical corticosteroids under occlusion should be avoided. Prescribing topical corticosteroids in inadequate amounts can also contribute to suboptimal control of AD or non-adherence. The rule of thumb is that 30 g of medication are needed to cover the entire body of an average adult.

Therefore, patients with widespread disease need to be prescribed sufficient quantities of medication. In addition, obtaining medications in larger quantities may result in significant savings for the patient.

A major reason for treatment failure with topical corticosteroids is noncompliance as a result of parental or patient fear of side effects, including skin atrophy, telangiectasias, and possibly systemic absorption resulting in hypothalamic- pituitary-adrenal (HPA) axis suppression.

A study with fluticasone propionate 0.05% cream (group V) in children as young as 3 months with AD showed that this medication was safe and effective even when applied twice daily to the face and over significant areas of the body for up to 1 month.

Studies using desonide 0.05% ointment (group V) or aqueous gel (group VI) found no evidence of HPA axis suppression in children with AD for up to 4 weeks of twice daily applications.

Topical calcineurin inhibitors approved for AD include tacrolimus ointment (Protopic) 0.03% and pimecrolimus cream (Elidel) 1% (both for children 2 years and above), and tacrolimus ointment 0.1% (for adults). These medications use different anti-inflammatory mechanisms as compared with topical corticosteroids.

Because they do not cause skin atrophy, these medications are especially useful for treatment of AD involving the face, including periocular and perioral areas.

However, based on animal studies and case reports, the Food and Drug Administration has issued a ‘‘black box’’ warning for continuous use of both tacrolimus ointment and pimecrolimus cream because of concerns for possible development of malignancies.

Since the issue of the warning, case-control studies involving up to 300,000 patients have not shown any association between the use of these medications and the risk of malignancy.

Systemic exposure in study animals treated with high oral doses or nonstandard formulations of pimecrolimus, that result in immunosuppression and development of lymphoma, have been 31 to 343 times higher than the highest individual systemic exposure ever observed, among pediatric patients with extensive AD lesions treated with pimecrolimus cream.

The Topical Calcineurin Inhibitor Task Force of the American College of Allergy, Asthma and Immunology and the American Academy of Allergy, Asthma and Immunology reviewed all available data and concluded that the risk/benefit ratio of topical pimecrolimus and tacrolimus, were similar to those of most conventional therapies for the treatment of chronic relapsing AD.

Therefore, as-needed use of these medications should continue to be considered in patients with persistent AD, especially on skin areas prone to develop atrophy from topical corticosteroids.

Alternative and Experimental Treatments

Treatments for patients with recalcitrant AD can be challenging. Wet-wrap treatment with topical corticosteroids has been shown to be efficacious although potential side effects include secondary infection and HPA suppression. Therefore such treatments should be performed under the supervision of physicians who are familiar with them.

A short course of an oral corticosteroid can also be considered for severe flare of AD, but the corticosteroid dose should be tapered over 1 week to decrease the chance of a rebound effect off the systemic corticosteroid. Cyclosporin A and ultraviolet phototherapy have been shown to be efficacious for severe AD.

But their systemic side effects (eg, renal toxicity with Cyclosporin A) and the risk of malignancy are of concern. Other experimental treatments include mycophenolate mofetil, azathioprine, methotrexate, and intravenous immunoglobulin. These treatments are also associated with significant systemic side effects and therefore should only be considered for the most severe AD patients.

Often, hospitalization of patients with a comprehensive approach, including addressing psychosocial aspects of this chronic relapsing disease, can lead to dramatic clinical improvement. The use of probiotics to treat or prevent AD has been an area of controversy. To date, no convincing evidence shows that probiotics are effective in AD.

Studies on the use of probiotics to prevent the development of AD have yielded conflicting results. Evening primrose oil has also been shown to be ineffective in the treatment of AD. There is also no convincing data to support the use of Chinese medicinal herbs in AD. In addition, the potential side effects of these medications are of concern.

Omalizumab or anti-IgE (Xolair) is approved for use in patients 12 years or older with allergic asthma that is inadequately controlled on high-dose inhaled or systemic corticosteroids.

There have only been few case reports on the use of this medication in AD and the results in these studies conflicted. Therefore, well-designed controlled trials are needed. Finally, controlled studies with montelukast have not shown benefit in AD.