What Is Contact Dermatitis
Contact dermatitis is the second most common dermatological diagnosis. A survey
of medical professionals in 1995 found that contact dermatitis resulted in
almost 8.4 million outpatient visits to medical facilities. Contact dermatitis
is different from the contact urticaria described in our article "
What are Hives". With contact dermatitis, the resulting skin condition can last for
days or weeks and will continue as long as the skin continues to be exposed to
the irritant. The rash is localized; and only involves the upper layers of the
skin, and is the result of direct contact with an irritating substance.
Contact dermatitis can appear as a red rash. Blisters or pustules may or may not
be present. If blisters are present, they may weep and ooze before crusting
over. An intense itching or burning or even pain may be present. Sometimes the
skin actually will feel warm to the touch.
There are three major types of contact dermatitis: irritant, allergic, and
Irritant Contact Dermatitis
As suggested by the name, irritant contact
dermatitis occurs when a substance that causes an irritation is exposed to the
skin. In this type of contact dermatitis, the skin is actually injured. Common
irritants are strong acid or alkaline substances, chemicals such as sodium
laurel sulfate (common in soaps and shampoos), latex, cleansers and solvents.
The hands are the most common site of irritant contact dermatitis.
Allergic Contact Dermatitis
With this type of contact dermatitis, the immune
system is involved and a true allergic reaction occurs. One of the most common
causes of allergic contact dermatitis is the urushiol oil in the toxicondendron
family of plants. This plant family includes poison ivy, poison oak, and poison
sumac. Metals such as nickel are also common allergens. This metal is commonly
used to make belt buckles, jewelry, watches, pant and shirt buttons as well as
Clothing can also be a source of allergic contact dermatitis. The
chemicals used in the permanent press process and used to tan leather can be a
source of allergens. Many of the fragrances and masking fragrances used in
personal care items also cause allergies. If the fragrance is not the cause, it
could be the preservatives used. Quaternium-15 is a widely used preservative as
it is a formaldehyde releaser and is frequently the culprit in allergic contact
Photo Sensitive Contact Dermatitis
This contact dermatitis occurs when a
combination of ultraviolet light and a sensitizing agent cause a rash or
blisters. This is also known as sun poisoning or photo allergy. A subset of this
condition is phytophotodermatitis. In this condition when the skin is exposed to
the sap of certain plants in conjunction with ultraviolet light blistering
occurs. Carrots, rue, and fig are some of the plants that can cause this rare
condition. This is not to be confused with photosensitive allergic dermatitis
that is caused purely by exposure to ultraviolet light and does not require
contact with any substance.
Treatment of mild contact dermatitis can be done at home. More serious or
chronic symptoms should be addressed by a medical professional. The most
important treatment is washing with plenty of water. This should be the first
action you take in an effort to remove as much of the irritating substance as
possible. In the case of contact with metal, remove the metal. If the cause is
exposure to a strong alkaline substance, you can rinse with lemon juice or
vinegar to reduce the alkalinity. If blisters are present, use cool compresses
several times a day. Soaking in oatmeal baths and application of calamine lotion
can relieve itching. Corticosteroid creams such as cortisone can also bring
relief. If the contact dermatitis is caused by an allergic reaction oral
antihistamines will help. Antihistamines will not help for irritant or photo
sensitive contact dermatitis.
If you have a chronic rash and are not sure of the cause, your doctor can
perform allergy testing to determine if allergies are the root of your problem.
Your doctor can also help you determine if the cause is irritant or allergic in
nature. Regardless of the cause, if you have a rash that persists you should
seek medical attention.
Wishing you the best of health
The Allergy Store