EczemaNet Article
Infection Common in Patients with Atopic Dermatitis

The red, cracked, and unbearably itchy skin that develops when atopic dermatitis (AD) flares is not only uncomfortable. It also makes one more susceptible to infection. To help patients and their caretakers cope, this article explains:

• Why people with AD are more susceptible to infection

• How to recognize the signs and symptoms of infection

• When to seek medical care

• What you can do at home to reduce the risk of infection

Why people with AD are more susceptible to infection
Research shows that about 90% of people with AD have the Staphylococcus aureus (staph) bacteria present on their skin. By comparison, less than 5% of people without AD have staph on their skin. When a person with AD scratches, the skin often breaks. This allows microorganisms on the skin, such as bacteria, viruses, and fungi, to enter the body. Additionally, a study shows that people with AD cannot produce effective amounts of two natural antibiotic proteins that the immune system needs to fight infection.¹

With staph constantly present on the skin and the immune system unable to adequately fight infection, it is easy to see why people with AD develop infections when their skin flares and they scratch.

How to recognize the signs and symptoms of infection
Children and teens with AD are especially prone to developing skin infections caused by staph (bacteria) and herpes simplex (virus). Fungal infections may also occur. It is important to recognize the signs and symptoms of infection, and consult your dermatologist as soon as they appear. An untreated infection may be the reason AD does not respond to treatment. Signs and symptoms to watch for are:

• Honey-colored crusting and pus-filled blisters. When a bacterial infection, such as one caused by staph, occurs, honey-colored crusts usually form. This is a sign of infection. Another sign is the appearance of pus-filled blisters that form over patches of AD. These blisters may pop, weep, and form crusts.
   

• Redness. When the skin becomes infected with bacteria, it becomes very red. Widespread red scaly patches and plaques that may crust and discharge pus, usually indicate a staph infection.
  
  Streaking or spreading redness also indicates infection.
   

• Swelling/Inflammation. If the area feels enlarged or unusually warm, it may be infected.
   

• Fever. When infection develops, the body’s temperature sometimes rises to create an unfavorable environment for the microorganisms, such as bacteria, viruses, or fungi, causing the infection.
   

• Lesions that resemble cold sores or fever blisters. These may be signs of eczema herpeticum, a viral infection that also causes cold sores. Eczema herpeticum can spread rapidly.
  
  In the early stages, you will see numerous small blisters filled with clear fluid that are surrounded by bright red halos. Within one or two days, the blisters will break, leaving small round breaks in the surface of the skin. The skin may become very sore, and the patient will feel quite ill.
  
  Even a person with mild AD can develop a severe infection from the virus. For this reason, it is important to seek medical attention if you see these signs. In rare cases, eczema herpeticum can be life-threatening.
  
  Be sure to keep children with AD away from anyone who has a cold sore.

When to seek medical care
You should contact your dermatologist whenever you believe an infection has developed. Dermatologists recommend that the infection be treated early to prevent the condition from becoming worse.

Your dermatologist will determine what is causing the infection and usually prescribe medication. Antibiotics are used to treat infections caused by bacteria, such as staph or strep. Some antibiotics are applied to the skin; others come in pill or liquid form.

It is important that the patient take all antibiotics exactly as directed. When a patient does not finish taking an antibiotic, there is a chance that the infection will not clear. While the patient may feel better, some bacteria can remain. When this happens, the infection becomes increasingly hard to treat because the remaining bacteria can develop a resistance to the medication. When the medication is given again and it no longer works, this is called “antibiotic resistance.”

Diluted bleach baths may be recommended for some patients to help reduce the number of bacteria on their skin. If so, your dermatologist will provide you with instructions for preparing these baths. It is important that this therapy not be tried at home unless prescribed. In some cases, phototherapy (treatment with light) may be recommended to reduce the bacteria colonizing the skin and to reduce inflammation. Topical steroids or topical calcineurin inhibitors, such as pimecrolimus or tacrolimus, may be prescribed to reduce overall skin inflammation.

Antibiotics that treat bacterial infections are not effective at treating viral infections. The herpes simplex virus may be treated with a medication called acyclovir, which comes in pill and liquid form. Acyclovir also can be given as a shot. Other medications used to treat this viral infection are famciclovir and valacyclovir.

In addition to prescribing medication, your dermatologist will review your skin care routine to make sure you are doing everything possible at home to prevent future flare-ups, which can lead to infection.

What you can do at home to reduce the risk of infection
The key to preventing infection is to eliminate flare-ups. Here are some tips that can reduce flare-ups:

1. Identify and eliminate potential triggers. Triggers cause the skin to flare. Common triggers include wool, soaps, pet fur, perfumes, cosmetics, and household cleaners. Observe when flare-ups occur to learn what irritates the skin, and avoid future contact with these triggers.

2. Keep skin moisturized. When the skin becomes dry and itchy, the desire to scratch becomes overwhelming. Regular use of a non-irritating moisturizer can keep the skin from becoming dry and itchy. Skin should be moisturized frequently throughout the day and always after bathing while the skin is still moist.

3. Avoid excessive bathing. The bath should be short, the water lukewarm, and the soap mild. Be sure the soap does not irritate the skin, and use the soap only when needed. Your dermatologist can tell you how often to bathe.

4. Keep indoor temperature and humidity consistent. Using a humidifier in the winter and air conditioning in the summer can help.

5. Avoid contact with anyone who has cold sores or chicken pox. Cold sores are caused by the herpes simplex virus. People with AD can develop eczema herpeticum when exposed to the herpes simplex virus. The virus that causes chicken pox, varicella zoster, also should be avoided.

6. Reduce stress as much as possible. Know what causes stress, such as taking a test or competing in a sporting event, and develop strategies for managing the stress.

7. Apply cold, wet wraps. If itching becomes intense, ask your dermatologist if you should apply a cold, wet wrap. This therapy can effectively relieve itching.

8. Minimize perspiring. One’s own perspiration often irritates the skin and causes a flare-up. Avoid overheating, and do not wear synthetic fabrics, such as polyester, which trap perspiration. Dermatologists recommend wearing cotton and dressing in layers to avoid overheating. Taking breaks when exercising also may be helpful.

9. Keep fingernails short. Short nails decrease the likelihood that scratching will puncture the skin. Keeping nails short and wearing cotton gloves at night may help prevent scratching that punctures the skin while asleep.

For more information about preventing flare-ups, see “Preventing Flare-ups”.

Reference:
¹ Ong PY et al. “Endogenous antimicrobial peptides and skin infections in atopic dermatitis.” New
  England Journal of Medicine. 2002. October 10;347(15):1151-60.

An educational program brought to you by the American Academy of Dermatology.