Eczema Treatment: Topicals
Topical preparations are almost always part of a treatment program for eczema.
A topical preparation is generally applied externally to the skin. A topical's base preparation, referred to as the topical vehicle, must take into account its effect on improvement of the skin barrier function and its efficacy regarding penetration of the drugs which it carries. Topical vehicles typically fall into one of three categories: lipophylic, amphiphilic, or hydrophylic. Topical preparations may be called by different names depending on the strength of the medication they contain. The list below represents the name of the preparatation relative to the potency of medication from highest to lowest:
Typical drugs contained in topical preparations include:
- Glucocorticoids (e.g. hydrocortisone)
- Topical Immunomodulators (TIMs)
- Topical Calcinuerin Inhibitors (TCIs)
Glucocorticoids, also referred to as steroids, are substances similar to hormones your body makes naturally. Hydrocortisone is an example of a steroid commonly sought by eczema sufferers in an over-the-counter (OTC) form (typically in strengths from 0.5% to 1%). Topical steroids are usually classified into different potency classes, including low, moderate, and high potency classes. The three main functions of glucocorticoids include vasoconstriction, anti-inflammatory, and anti-proliferative effects. These drugs reduce reddening, swelling, and itching, and are indicated in almost all treatment programs.
Topical steroids carry a host of side effects though are typically well tolerated when used as prescribed by a healthcare provider. Abrupt discontinuation can lead to a rebound effect and eczema flare-up. Glucocorticoids are used in combination with ultraviolet (UV) phototherapy routinely to improve therapeutic results. Generally, UV phototherapy allows the healthcare provider to prescribe lower potency glucocorticoids, thus reducing side effects.
Topical Immunomodulators (TIMs) interrupt or suppress the immune system, often through a series of interactions. These include calcineurin inhibitors, also called TCIs. These drugs interact with T-cells and reduce proliferation of substances which perpetuate the eczema skin cycle.
Two substances, tacrolimus and pimecrolimus, have received much recent attention. These drugs, in combination with targeted UV phototherapy, have been shown to be highly effective in combination for treatment of vitiligo. Research into this combination therapy for eczema may occur in the future.
Antihistamines work to decrease allergenic activity in the body. These drugs can significantly reduce itching and reduce IgE levels. Several commercial brands of topical antihistamines are available. Commonly, topical antihistamines are found in such products as mosquito bite creams and Benadryl cream. Orally, antihistamines can have sedatory properties which may lead to reduced stress for eczema sufferers and thus reduced disease expression. Topical antihistamines do not affect the body strongly enough to have sedatory effects.
Staphylococcus aureus and other bacteria represent a frequent challenge to treatment. These bacteria cause infection, oozing and weeping wounds, and can produce superantigens which stimulate T-cells leading to desensitization to glucocorticoids (rendering them less effective). Additionally, staph causes colonization which can lead to recurrent flares. Common antibiotics include fusidic acid and erythromycin.
Unlike bacteria, human cells and fungal cells are eukaryotic. Because of this similarity, fungal infections are harder to fight. Antimycotics take advantage of the differences between human cells and fungal cells. Some antimycotic preparations have anti-inflammatory and antibacterial properties as well. Common tradenames include Nizoral and Lotrimin.