East Central Indiana
06/24/2017
Medical Dermatology

Contact Dermatitis

  • Contact Dermatitis
    Contact dermatitis is the inflammation of the outer layers of the skin caused by contact with a particular substance.
  • Contact Dermatitis
    Symptoms of contact dermatitis vary from person to person, but often include itching, redness, swelling, blisters, crusting, oozing, and scaling.

About

Contact Dermatitis

Contact dermatitis defines inflammation of the skin that results from direct contact of a substance with the surface of the skin, which may or may not be related to an allergy.

Causes

A person develops contact dermatitis when something that touches the skin does one of the following:

  • Irritates the skin
  • Causes an allergic reaction

There are two types of contact dermatitis:

  • Irritant contact dermatitis is the most common form and is caused when substances such as solvents or other chemicals irritate the skin. The exposure produces red, often more painful than itchy, patches on the involved skin areas.
  • Allergic contact dermatitis occurs when a substance triggers an immune response. Nickel, perfumes, dyes, rubber, latex, topical medications and cosmetics frequently cause allergic contact dermatitis. More than 3,600 substances can cause allergic contact dermatitis.

Risk Factors

Anyone can develop contact dermatitis. Your risk factor may be increased if you are in regular contact with an irritant or allergen, or if you already have allergies to certain substances, such as plants, chemicals, or medications. People working in certain professions have a higher risk. Sometimes this is referred to as occupational dermatitis.

People who are more likely to get occupational dermatitis include:

  • Nurses (and other health care workers)
  • Beauticians
  • Bartenders
  • Chefs (and others who work with food)
  • Florists (and others who work with plants)
  • Construction workers
  • Janitors
  • Mechanics
  • Plumbers

Symptoms

Signs and symptoms of contact dermatitis rarely appear on contact. It may take a few hours for your skin to react. If this is your first time that your skin has an allergic reaction to that substance, weeks may pass before you notice anything. However, some people do develop a severe allergic reaction known as anaphylaxis (an-uh-fuh-lax-sis). Symptoms occur within seconds or minutes. A person may have:

  • Difficulty breathing due to swelling in the throat
  • Swollen face and/or eyes
  • Confusion

The entire body reacts during these events. If you have any of these symptoms, you need immediate medical care.

During normal contact dermatitis reactions, when signs and symptoms do appear, you may have:

  • Itchy skin, which can be intense
  • Rash, including red, swollen, hot skin
  • Excessively dry skin
  • Burning
  • Stinging
  • Hives, which are round welts on the skin that itch
  • Fluid-filled blisters
  • Oozing blisters that leave crusts and scales

If exposure to the allergen continues, your skin may:

  • Flake and crack
  • Become scaly
  • Darken, thicken, and feel leathery

Diagnosis

To diagnose this common skin condition, dermatologists:

  • Examine your skin and the developing rash.
  • Review your medical history
  • Ask probing questions about your lifestyle to determine what may be causing the rash

If your dermatologist suspects that you have an allergy, patch testing may be recommended. This offers patients a safe and effective way to find out if your skin has developed an allergic reaction to anything. A patch test includes applying patches to your skin that contain small amounts of possible substances which may be causing the allergy for a period of time. After this time, the patches are removed to inspect the skin for reactions.

*Source:

American Academy of DermatologyAmerican Academy of Allergy, Asthma, and Immunology

Treatment

Treatment

Treatment is the same for both types of contact dermatitis.

The steps involved during treatment are:

  • Avoid or lessen the exposure to the substance that is causing the rash.
  • Treat the rash, often using antihistamine pills, moisturizer, and a corticosteroid cream.
  • Severe reactions may require stronger medications, such as prednisone.
  • Wet dressings and oatmeal baths can help soothe symptoms until the rash clears.

By avoiding what caused the rash, most people can avoid flare-ups.

If you work with substances that caused the rash, you can still avoid a rash. Your dermatologist can recommend ways to work and products to use. More than 80% of people diagnosed with occupational dermatitis successfully manage the condition and recover without any problems.

*Source:

American Academy of DermatologyAmerican Academy of Allergy, Asthma, and Immunology

FAQs

What is contact dermatitis?

Contact dermatitis is a condition in which the skin becomes red, sore, or inflamed after direct contact with a substance. There are two types of contact dermatitis: irritant or allergic.

What is a patch test?

Patch testing is a diagnostic test that may determine which allergen is causing the skin to become irritated.

What is occupational dermatitis?

Occupational dermatitis is a skin disorder caused by coming into contact with certain substances in the workplace. It is therefore termed contact dermatitis. Contact dermatitis is the most common work related disease in Ireland. It can have long term consequences for workers health and in extreme cases it can hinder their ability to continue working. Research has indicated that 10 years after the condition first occurs, up to 50% of affected workers will still have some skin problems.

It has financial implications in terms of ongoing medical treatment, absence from work, social welfare compensation and possible civil claims. It brings other costs in terms of pain and suffering to affected workers. In many instances it may be totally preventable by simple inexpensive measures.

How many types of dermatitis are there?

There are 2 forms of contact dermatitis, irritant and allergic.

What is contact irritant dermatitis?

In contact irritant dermatitis the substance that damages the skin is known as the irritant. A highly irritant substance is known as a corrosive. Irritant dermatitis makes up about 80% of contact dermatitis. The other 20% is allergic.

There are several ways that skin damage can be caused:

  • Detergents, soaps such as in repeated hand washing or the use of solvents can remove the protective oily layer and so leave the skin exposed to damage.
  • Physical damage such as friction, minor cuts for example from fibre glass and grazes can breakdown the protective layer and allow substances access.
  • Chemical such as acids or alkalis can burn the layer.

Irritation is analogous to a chemical burn. It acts by eroding or burning the outer protective layers of the skin. Irritant contact dermatitis usually occurs only on the parts of the body in direct contact with the irritant substance e.g. hands, forearms, face.

Common irritants are wet work, cutting oils, solvents and degreasing agents which remove the skins outer oily barrier layer and allow easy penetration of hazardous substances, alkalis and acids (see Table 1). Wet cement coming into contact with exposed feet and hands is a particular example of a skin irritant.

What is allergic contact dermatitis?

In this case, the substance causes the worker to become sensitized or to develop an allergic reaction some time after initial contact. The type of allergic mechanism is known as Type IV or delayed hypersensitivity. People do not become allergic to a substance immediately at first contact. The sensitization period( the time between contact and the development of an allergy) can vary from a number of days to months or even years. The risk of becoming allergic depends on several factors:

  • The nature of the substance. Substance with a higher likelihood to cause allergy is known as a skin sensitizer.
  • The nature of contact. The higher or more repeated the exposure the more likely it is for the individual to develop sensitization.
  • The vulnerability of the host. Typically people with other allergies are NOT particularly more vulnerable to developing contact allergic dermatitis. Individuals with a previous history of non allergic dermatitis ARE more vulnerable. This may be because the sensitizer may more easily enter the bloodstream in those individuals.

Once the individual becomes sensitized, each time he/she comes into contact with the sensitizing substance, even in very small amounts, dermatitis will develop. This is different to irritant dermatitis which is dose related. The long term health consequences and ability to remain at work can be significant. In general the majority of an exposed occupational group do NOT become sensitized. It is an idiosyncratic or individual reaction.

Sensitization is specific to one substance or to a group of substances that are chemically similar. Once sensitized a person is likely to remain so for life. In allergic dermatitis the rash can occur in areas of the skin not in direct contact with the substance - the so called “Id” reaction.

Common sensitizers are chromate's (found in cement), nickel (cheap jewellery), epoxy resins, formaldehyde, wood dust, flour, printing plates, chemicals and adhesives.

*Source:

Health & Safety Authority

Videos

Contact Dermatitis Videos