What is contact dermatitis?


Dermatitis, also known as eczema, refers to a rash that evolves and changes. In some cases, the affected area may be blistered and swollen. Dermatitis can result from a variety of causes and exposures. It also differs widely from person to person. The primary type of dermatitis diagnosed and treated at the Contact Dermatitis Institute™ is known as contact dermatitis.

Contact Dermatitis

Contact dermatitis is a rash that occurs when your skin comes into contact with a substance that causes your immune system to mistakenly think that it is under attack. Your immune system then sends antibodies to “fight” the “attacker.” This reaction can happen at any time. It doesn’t matter if it is your first contact with a substance or if you have used it for years. Once you have developed a contact allergy, it is likely to recur and you may have it for the rest of your life.

There are two types of contact dermatitis – irritant and allergic. We may diagnose irritant or allergic contact dermatitis based on evaluation of your medical history, occupation, symptoms, and with a procedure called patch testing. Treatment of both irritant and allergic contact dermatitis is based on avoiding contact with the substance(s) that caused the reaction.

Irritant contact dermatitis (ICD) occurs in response to irritating substances such as household cleaners, harsh soaps and industrial solvents. Your skin can react to these substances within minutes or hours and stops reacting soon after they are gone.

Allergic contact dermatitis (ACD) occurs when a person’s immune system responds to contact allergens, such as fragrances, preservatives, nickel, gold, and many others. Allergic reactions to contact allergens can develop hours or days after exposure and may take weeks to heal. A personal or family history of other allergies may increase a person’s chance of developing this skin condition.

Other forms of dermatitis include but are not limited to the following:

  • Atopic dermatitis, also known as eczema, is a familial disease which can affect infants, children, and adults. It is often accompanied by asthma or allergies.
  • Nummular dermatitis is characterized by coin- or disc-shaped lesions primarily located on the extremities, buttocks, and trunk.
  • Seborrhea dermatitis causes red and flaky patches of skin typically located on the scalp and face.
  • Stasis dermatitis occurs when varicose veins or other circulatory conditions cause blood or fluids to pool under the skin.

To learn more about Contact Dermatitis, please watch this informative video, “What is Contact Dermatitis?”

Common Causes for Contact Dermatitis

The causative allergens for ICD and ACD are vast and can be found almost anywhere. Some substances can even cause the allergic reaction only after exposed to sunlight. Without patch testing, it can be very difficult to determine what substance is causing your allergic reaction.

Many common substances are known to cause allergic contact dermatitis:

  • Nickel
  • Poison ivy, oak or sumac (urushiol is a strongly allergenic oil produced by these plants)
  • Jewelry or other metals
  • Fragrances and flavorings
  • Clothing or shoes
  • Antibiotics, antihistamines and antiseptics (typically used in topical medications)
  • Household cleaning products
  • Formaldehyde and other chemicals
  • Natural rubbers (latex)
  • Skin cleansers
  • Strong detergents or soap

Occupational contact dermatitis is a rash caused by a substance your skin has contact with in the work environment. Industrial solvents, chemicals and oils, cleaning agents, wet work, dust, water and friction often cause occupational contact dermatitis.

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