ATOPIC DERMATITIS - "ECZEMA"

Eczema is an extremely common skin disorder. It is intimately related to individuals who have allergies or the genetic ability to have allergies. It is characterized by TH2 response, which, as discussed in the introduction, is the immune response characterized by the shift to IgE production and the frequent development of eczema, allergic rhinitis, or asthma. Eczema often starts in babies and is frequently associated with food allergies in the first year of life. As the child grows older, eczema is frequently associated with inhalant allergy (IgE mediated allergy) or contact dermatitis (cell mediated allergy). There is a significant genetic component. There also is a significant environmental component (in addition to allergen exposure) where heat, irritants, drying of the skin, infection, and stress all exacerbate eczema. This interaction of genes, the environment, and allergy is extremely complex and not completely understood, particularly when applied to a single individual. The underlying problem is inflammation in the bottom layers of the skin. Thus, you can see the similarity between eczema and other allergic conditions (see the introduction section regarding allergic inflammation causing rhinitis and asthma).

The Rash

In very young children the rash is usually dry, only slightly scaly, and always itchy. When active the rash usually has a red color. It can progress to areas that are crusted or plainly raw, open, and oozing fluid. When the rash is severe and resistant to standard treatments, there is often secondary infection of the eczematous area or of another area of the body. As the child grows older the rash can become thickened (lichenified) due to constant scratching and the skin can take on a leathery appearance. A severe scratching episode can render the skin almost unrecognizable. In young children the rash can appear anywhere (except the diaper area is usually spared) and in older children and adults usually is found around the joint creases (i.e. elbows, knees) or on the face (cheeks, eyelid area), although it certainly can appear anywhere. Occasionally, the eczematous rash can be raised and have a slight blistered appearance. There are specific variants that occur. Two that deserve special attention are dishydrotic eczema (characterized by the appearance of small itchy-painful deep blisters that occur on the palms and soles of the feet, often followed by peeling of the skin in the affected areas) and nummular eczema (characterized by small round discrete patches of eczema, often on the legs or arms, and often resistant to treatment). Most importantly, you must appreciate that the rash is highly variable in individuals. Some will have a few episodes in infancy and have the process disappear, others will have occasional mild episodes into adult life, and some will have continuous disease activity throughout their lifetime. If eczema is present at puberty or develops in adulthood it usually continues throughout life. However, in any given individual eczema can be highly variable, ranging from rare intermittent episodes with the skin being totally normal in between episodes to occasional severe prolonged episodes. Virtually all individuals with eczema suffer from dry skin and itching is always a prominent feature.

It is important not to confuse this condition with other diseases such as irritant dermatitis ( i.e.diaper rash), seborrheic dermatitis, contact dermatitis, skin infections (yeast and bacterial-impetigo), psoriasis, scabies, drug rashes, etc.

The Treatment

Basics

No matter what type of eczema you have, there are several basic treatments that apply to all. You must prevent the skin from becoming overly dry. All irritants should be avoided. This includes most basic soaps (which are caustic) and true lotions (most have an alcohol base). Skin preparations should be simple, avoiding multiple compounds and odours (fragrant or perfumed). Washing eczematous areas should be done very gently, preferably with water alone (or with a very mild cleansing agent that does not bother that individual). It is critical that as soon as washing has been finished the eczematous areas should be only lightly patted dry and immediately covered with a moisturizer or anti-inflammatory preparation to seal the moisture into the skin. You must never allow eczematous areas to dry out completely after washing, as this worsens the inflammatory process. Frequent washing must be avoided. In general, ointments are preferable to creams. Ointments have an oil base and seal moisture into the skin more effectively. Unfortunately, ointments are "greasy" and many individuals do not like to use them. Creams have a water base, and do not seal in water as effectively. However, creams when applied properly, do not leave a trace on the skin, and are preferred by many individuals (especially in exposed areas). Ointments usually have far fewer compounds in them and must be used when individuals have problems tolerating multiple different creams (especially ones with fragrances). I think creams are acceptable if the eczema is under good control. However, if the eczema is flaring, ointments must be used to obtain proper control and many individuals would obtain better long-term control if they continued to use ointments regularly. A critical area, which is very frequently overlooked, is how the ointment-cream must be applied. Normal skin consists of multiple upper dead skin layers lying on top of the bottom live growing layer. The top layers protect the growing layer. When you apply your ointments-creams, you must thoroughly rub them into the affected areas (rub each application into the skin for at least 30 seconds and usually " until gone"). This allows your topical skin treatment to soak into the top dead layers of skin so that it can exert its effect on the bottom inflamed layer over the next several hours. If applied properly, you should never need to apply your topical treatments more often than two or three times daily. The most common mistake I see, is the individual merely applies the ointment-cream to the skin in one simple swipe and the topical treatment simply gets rubbed off the skin over the next few minutes (i.e. on clothing, bedding, etc.). This scenario results in no medication reaching the inflamed area and no sealing of moisture into the skin. You must take time to apply these topical treatments and rub in well, or they will not work. A simple rule which you can follow to determine what you should be treating the skin with : if the skin is dry, flaking, and itchy-topical moisturizers should be applied aggressively; if the skin is significantly red or the skin surface is damaged (indicating significant underlying inflammation)-topical anti-inflammatories should be applied as discussed below.

Advanced

I could spend a tremendous amount of time discussing medication. However, the treatment modalities are fairly straightforward. If the eczema is under good control, moisturizers should be used to maintain good control and skin hydration. This means that all eczematous areas must have a moisturizer applied after having a bath or shower and must always be applied at bedtime. If this is done faithfully, many flares can be avoided. Unscented moisturizers such as EucerinTM, Glaxal BaseTM, or MoisturelTM and others are appropriate. If your eczema flares, a topical anti-inflammatory should be used two or three times daily on all affected areas. Most topical anti-inflammatories are corticosteroids. These agents are effective and safe when used properly to obtain good control. Once good control is obtained, topical anti-inflammatories are stopped and regular moisturizers are resumed. For very mild flares, sometimes increasing the use of moisturizers will suffice to obtain control. For individuals with severe persistent eczema, topical anti-inflammatories must be used regularly. There are different strengths of corticosteroids (steroids). In general the mildest steroid that will do the job should be employed. Hydrocortisone 1% is the mildest available and is safe on all areas of the skin. Potent steroids should be avoided on the face as they can cause the facial skin to thin and redden. Potent steroids often are required on thick skin areas (palms, soles).

Avoidance of irritants and excessive drying of the skin is mandatory and must be performed consistently during flares. If stress is an underlying factor, attempts should be made to control or minimize this. Allergen avoidance measures are useful in some individuals. This depends upon whether allergy is playing a major role in the continuation or flaring of the eczema. The individual must have a clear allergic tendency and positive skin tests indicating the ability to be atopic. Please see the section on allergy skin testing for a detailed discussion of this. If allergy is playing a direct role in an individuals’ eczema, then proper allergen avoidance will improve the eczema. In very young infants, food allergy often is involved. It is absolutely critical that avoidance of certain foods only be undertaken when a specific food has been proven to be a major factor by an allergist experienced in this area. Long-term avoidance of specific foods should never be done unless appropriate testing (to prove the allergy exists) has been done and proper continual medical follow-up is assured. Avoiding foods that are basic to nutrition is a serious step. Fortunately, most infants "outgrow" the food allergies that tend to drive eczema. What is not appreciated is that inhalant allergens (particularly dust mite) can drive eczema also. They can do this through direct inhalation and the typical IgE mediated allergic reaction or through direct contact - cell mediated delayed allergic mechanisms. In these individuals, avoidance measures (particularly the dust free bedroom) can have a tremendously positive effect on the eczema process. Again, if inhalant allergens are playing a role, proper avoidance will improve the eczema. In many individuals, multiple factors are playing a causative role, and these factors can change in importance over time.

Additional medications can also be helpful. If the itching is severe, antihistamines can help some individuals. I always try the nonsedating types (ReactineTM, ClaritinTM, AllegraTM AeriusTM) first. If itching and scratching at night (including difficulty sleeping) is a major problem the older sedating antihistamines can be used at bedtime (AtaraxTM,BenadrylTM, and others), but make sure they do not have a daytime “hangover” effect. As histamine is not a major player in the inflammation in chronic eczema, make sure it is really helpful before deciding to use long term, but, if the patient has concomitant rhinitis or asthma this is often appropriate. Occasionally patients with severe eczema will respond to the leukotriene blockers (AccolateTM or SingulairTM) used for asthma, but these medications do not have a formal approval for this indication. Singulair is definitely worth a try if the individual has concomitant allergic rhinitis or asthma. There are now two newer topical medications available that are proving to be extremely effective. These topical medications are similar in that both act to decrease the inflammatory response in the skin (topical calcineurin inhibitors). The names are Protopic TM (tacrolimus), which comes in 0.03% and 0.1% ointments, and Elidel TM (pimecrolimus) 1% ointment or cream. These two new topical agents are not steroids and are very safe to use on the face and thin skin areas along with regular thicker skin areas twice daily. Because these are topical immune system suppressants, they should not be used from head to toe for prolonged periods of time or on open-damaged skin areas without proper medical follow-up. While there has been concern that these medications may cause systemic immune suppression, all recent studies are pointing to the fact that these are very safe. Their main drawback is their high cost and a stinging-burning sensation experienced during the first few applications. Unquestionably, these two newer agents are a major addition to our topical treatment regimen.

During very severe flares where the skin is inflamed and often open (cracks or open weeping areas) the eczema patient has often developed a secondary bacterial infection in the skin that is driving the eczematous process. These individuals require antibiotic treatment, often in the form of both topical and oral antibiotics, in addition to their regular eczema preparations. Individuals with chronic eczema have a much higher rate of chronic carriage of bacteria (particularly Staphylococcus, and some strains of Streptococcus) in their nose or on their skin. Studies have shown patients with chronic eczema have defects in their skin defence against these bacteria.

Some individuals with severe generalized flares require oral prednisone for a period of time if adequate control cannot be attained otherwise. Prednisone is usually highly effective in settling the process, but carries with it major risks of side effects (see Contents section: Medications & Allergy) when used long-term. Also, when prednisone is stopped the eczema very frequently rebounds back to where you started from prior to instituting the prednisone. There are a variety of other systemic anti-inflammatories that are used in specialized centers including but not limited to: cyclosporine A, azathioprine, and phototherapy which will not be discussed in detail. Newer immune system modulators are also being investigated such as TNF inhibitors that are being used successfully in rheumatoid arthritis and inflammatory bowel disease.

Recent studies have shown immunotherapy (allergy shots) to be of significant benefit in some individuals with persistent moderate to severe eczema. I am now using immunotherapy more frequently for persistent eczema. However, it has been very clear that some eczema patients will respond very well to immunotherapy while others show little improvement. Similarly, studies with XolairTM (the monoclonal antibody to IgE receptor) are showing similar erratic results. There is no way at this time to tell which individuals will respond to these treatments, and this underscores the complex interplay of factors that drive eczema and the variability of these various factors in a specific individual. Immunotherapy might also exert a protective effect in patients with mild eczema, preventing the development of more severe eczema or improving the chance of eczema disappearing, but this remains to be proven.

SUMMARY

Triggers

-Allergens (food, inhaled, contact, autoantigens)

-Irritants (drying, heat, chemicals:soaps,detergents,chlorine,etc., mechanical)

-Stress

-Infection

-Genetic

Treatment

-Basic Skin Care (skin hydration, topical moisturizers-lubricants, avoidance of irritants)

-Topical anti-inflammatories (steroids from low to mid to high potency, topical calcineurin inhibitors)

-Antimicrobial-antibiotics (topical and/or systemic)

-Systemic anti-inflammatories (prednisone, and others)

-Immunotherapy; (possibly Xolair TM)

In closing, I would like to stress the importance of proper basic skin care (hydration) in the eczema patient. The majority of individuals who fail to control their eczema, do so because of a failure to apply these basic principles.

Reprinted with permission – Dr. Bruce Sweet 2007