Contact Dermatitis

from Healthline.com
Definition:

Contact dermatitis is an inflammation of the skin caused by direct contact with an irritating substance.
Alternative Names

Dermatitis – contact; Allergic dermatitis; Dermatitis – allergic; Poison ivy; Poison oak; Poison sumac
Causes, incidence, and risk factors

Contact dermatitis is an inflammation of the skin caused by direct contact with an irritating or allergy-causing substance (irritant or allergen). Reactions may vary in the same person over time. A history of any type of allergies increases the risk for this condition.

Irritant dermatitis, the most common type of contact dermatitis, involves inflammation resulting from contact with acids, alkaline materials such assoaps and detergents, solvents, or other chemicals. The reaction usually resembles a burn.

Allergic contact dermatitis, the second most common type of contact dermatitis, is caused by exposure to a substance or material to which you have become extra sensitive or allergic. The allergic reaction is often delayed, with the rash appearing 24 – 48 hours after exposure. The skin inflammation varies from mild irritation and redness to open sores, depending on the type of irritant, the body part affected, and your sensitivity.

Overtreatment dermatitis is a form of contact dermatitis that occurs when treatment for another skin disorder causes irritation.

Common allergens associated with contact dermatitis include:

* Poison ivy, poison oak, poison sumac
* Other plants
* Nickel or other metals
* Medications
o Antibiotics, especially those applied to the surface of the skin (topical)
o Topical anesthetics
o Other medications
* Rubber or latex
* Cosmetics
* Fabrics and clothing
* Detergents
* Solvents
* Adhesives
* Fragrances, perfumes
* Other chemicals and substances

Contact dermatitis may involve a reaction to a substance that you are exposed to, or use repeatedly. Although there may be no initial reaction, regular use (for example,nail polish remover, preservatives in contact lens solutions, or repeated contact with metals in earring posts and the metal backs of watches) can eventually cause cause sensitivity and reaction to the product.

Some products cause a reaction only when they contact the skin and are exposed to sunlight (photosensitivity). These include shaving lotions, sunscreens, sulfa ointments, some perfumes, coal tar products, and oil from the skin of a lime. A few airborne allergens, such as ragweed or insecticide spray, can cause contact dermatitis.

Symptoms

* Itching (pruritus) of the skin in exposed areas
* Skin redness or inflammation in the exposed area
* Tenderness of the skin in the exposed area
* Localized swelling of the skin
* Warmth of the exposed area (may occur)
* Skin lesion or rash at the site of exposure
o Lesions of any type: redness, rash, papules (pimple-like), vesicles, and bullae (blisters)
o May involve oozing, draining, or crusting
o May become scaly, raw, or thickened

Signs and tests

The diagnosis is primarily based on the skin appearance and a history of exposure to an irritant or an allergen.

According to the American Academy of Allergy, Asthma, and Immunology, “patch testing is the gold standard for contact allergen identification.” Allergy testing with skin patches may isolate the suspected allergen that is causing the reaction.

Patch testing is used for patients who have chronic, recurring contact dermatitis. It requires three office visits and must be done by a clinician with detailed experience in the procedures and interpretation of results. On the first visit, small patches of potential allergens are applied to the skin. These patches are removed 48 hours later to see if a reaction has occurred. A third visit approximately 2 days later is to evaluate for any delayed reaction. You should bring suspected materials with you, especially if you have already tested those materials on a small area of your skin and noticed a reaction.

Other tests may be used to rule out other possible causes, including skin lesion biopsy or culture of the skin lesion (see skin or mucosal biopsy culture).

How can I help my doctor diagnose my skin condition?

Keep a “diary” of when your symptoms appear, get worse or improve. It also helps to write down where your symptoms occur on your body, and how long they last. If you notice that your skin gets worse after certain activities, record the reaction and the activity in as much detail as possible.

Workers in some occupations are more likely to develop allergic contact dermatitis, so it’s important to describe your work to your doctor. If you handle chemicals during the day, make a list of these or find their Material Safety Data Sheets (MSDS).

Treatment

Successful treatment of dermatitis symptoms depends on getting an accurate diagnosis from your physician. Depending on the type of dermatitis and the severity of skin reactions, a physician may prescribe corticosteroids, antifungal agents, antihistamines, barrier creams, and moisturizers for your skin, shampoos with salicylic acid, selenium, zinc, or coal tar, and oral medications. These treatments are intended to treat your symptoms and improve your skin’s condition.

Because there is often no cure for dermatitis, your physician should discuss ways to avoid allergen and/or irritant contact, and how to take better care of your skin. In addition, reducing stress can improve your immune system response and help restore your skin’s normal integrity

Initial treatment includes thorough washing with lots of water to remove any trace of the irritant that may remain on the skin. You should avoid further exposure to known irritants or allergens.

In some cases, the best treatment is to do nothing to the area.

Corticosteroid skin creams or ointments may reduce inflammation. Carefully follow the instructions when using these creams, because overuse, even of low-strength over-the-counter products, may cause a troublesome skin condition. In severe cases,systemic corticosteroids may be needed to reduce inflammation. These are usually tapered gradually over about 12 days to prevent recurrence of the rash.

Contact dermatitis usually clears up without complications within 2 or 3 weeks, but may return if the substance or material that caused it cannot be identified or avoided. A change of occupation or occupational habits may be necessary if the disorder is caused by occupational exposure.
Complications

Secondary bacterial skin infections may occur.

Call your health care provider if symptoms indicate contact dermatitis and it is severe or there is no improvement after treatment.
Prevention

Avoid contact with known allergens. Use protective gloves or other barriers if contact with substances is likely or unavoidable. Wash skin surfaces thoroughly after contact with substances. Avoid overtreating skin disorders.
References

Gober MD, DeCapite TJ, Gaspari AA. Contact dermatitis. In: Adkinson NF Jr, ed. Middleton’s Allergy: Principles and Practice. 7th ed. Philadelphia, Pa: Mosby Elsevier; 2008:chap 63.

Habif TP. Contact dermatitis and patch testing. In: Habif TP, ed. Clinical Dermatology. 5th ed. Philadelphia, Pa: Mosby Elsevier; 2009:chap 4.

FAQ: Winter Itch/ Eczema

The chill air of winter is more than just a harbinger of the holidays and snowy days. It can also precipitate the dry, itchy skin some people get during the cold weather and often leads to flare- ups for people with concurrent skin problems like allergic eczema or psoriasis.

What Causes It?
Indoor heating dries the air. In winter people often take hotter baths and showers and stay in them longer to warm up.Many don’t drink enough fluids. When the air surrounding the skin is drier, water evaporates out more easily, drying the skin. Natural protective skin oil is dissolved and washed away by the use of strong soaps, such as antibacterial or deodorant soaps. Dry skin is more sensitive and easily irritated; it gets itchy, then scratching that itch can actually cause a rash.

What Do I Do?
It is better to wash only once every day or two in winter, and showering is preferred, as it is less drying than a tub bath. Use lukewarm, not hot water, and stay in for no longer than 10-15 minutes. After rinsing, apply a dye and fragrance free moisturizer such as Aquaphor or Vaseline all over your body while it’s still wet. Avoid moisturizers that contain alcohol, as they can actually dry the skin more. Recent studies have shown that people with eczema have less amounts of a lipid called Ceramide in their skin and replacing it in the correct proportion with a ceramide containing moisturizer helps relieve this condition.

How Can I Prevent It?
Re-apply your moisturizer repeatedly through the day to keep your skin from getting dry.Don’t overheat your environment. Use a humidifier or set out pans of water to moisten your air. Also drink extra water to humidify from the inside out. Avoid dehydration caused by drinking alcohol and by neglecting to replace fluids lost through sweating. Use a sunscreen cream on exposed areas if going out in the sun, even in winter. If your dry skin or rash isn’t better in a week or so, see your doctor.

What Else Could It Be?
What can be worse than winter itch? Having a severe skin disease. Eczema and psoriasis are severe skin conditions that get worse in the winter. Although eczema is more prevalent in children, it also affects 10 percent of the adult population. Eczema can be described as skin that is itchy, dry, scaly, red, crusty, inflamed and sometimes oozing.

There are three main forms of eczema:

1. Irritant Contact Dermatitis. People who fail to moisturize or wash their skin too frequently can easily irritate it. Skin becomes red and dry and anything including water and baby shampoo can distress it.

2. Atopic Dermatitis. This is an internal chronic inclination towards eczema and it tends to flare in the winter. This form usually starts in infancy and affects those who have a family history of allergies, asthma, or dry, sensitive skin. Many children grow out of it as they get older but it tends to flare up again when they are adults.

3. Allergic Contact Dermatitis. This form is less common and occurs after an allergic reaction to a substance such as rubber, nickel, lanolin or a fragrance. This type of allergy develops over time and your skin could develop an allergy to something that did not irritate it in the past.

Other less common forms of eczema include seborrhoeic eczema, which affects the scalp and eye-lashes as a severe form of dandruff; and discoid eczema, which causes circular patches of eczema over the body.

Allergy tests such as skin/ blood tests and/ or patch testing is available to identify possible triggers for various forms of eczema and to direct appropriate treatment.

LINK:
Atopic Dermatitis/ Eczema