Do you have an extreme sensitivity to a stimulation of any kind? How does it annoy you? What is your response with the irritating object or situation? Do bra straps or stockings make your shoulders or thighs itch? Does your skin exhibit signs of extreme sensitivity to a type of hair product? Exhibiting signs of dermatitis?
Contact dermatitis is an inflammation resulting from a physical contact of an external substance to the skin. There are two types of contact dermatitis—the irritant type and the allergic type. Reactions may vary from person to person and from time to time. A history of any type of allergy increases the risk for this condition. Reaction may vary as a primary lesion that produces skin redness, edema and may reside to a large bulae or form secondary lesion that may cause skin crusting and other skin exacerbations.
Irritant Contact Dermatitis
This is the more common type of dermatitis. This type is non-allergic in form. It results mainly from direct reaction to rubbing, friction or excessive exposure to a chemical agent. There is no previous exposure to the irritating agent or object and the lesion produced is confined to the area of exposure. Symptoms of this type may include pruritus and burning sensation. The effect of the contact is evident within minutes or few hours at most. The duration of the reaction may be very short to very chronic or long term. The skin reaction depends on the skin condition or time of exposure to an open concentration of irritant.
photo of a diaper rash on an infant.
A common example of an irritant type of contact dermatitis is the diaper rash. In this case, the skin maybe vulnerable due to maceration from excessive humidity. The skin macerates due to the exposure to water, heat, cold, pressure and friction. This is also the same reason why a simple diaper rash should be treated immediately because it may lead to more complications such as a decubitus ulcer. Skin eruption occur in the area covered by the diaper. This is the most common type of rash in infancy  but is not restricted to the young aged because geriatric people who also uses diapers are also at high risk. Old people, especially those who are immobile, bed ridden, incontinent and have poor hygiene and sanitation. Prolonged contact to urine and feces may directly irritate skin and cause maceration. The worst part is, when this dermatitis leads to other types of infection.
Thin skin is less reactive than thick skin because a thicker skin has properties that makes it more resilient to exposure to moisture, heat and friction. Dry skin is less likely to react to contact dermatitis.
Some other common causes of irritant contact dermatitis are alkali soaps, detergents, bleaches, ammonia preparations.
Allergic Contact Dermatitis
This type of dermatitis is also known as contact eczema or includsional dermatitis. It results when an allergen comes in contact with a previously sensitized skin. The most common regions of the body that are usually affected are the head, neck, trunk, hands, abdomen, and lower extremities. Some agents may cause an allergic reaction such as hair dyes, hair sprays, shampoo, cosmetics, perfumes, and sometimes, metal jewelries. Clothing dyes and brasseries may also cause allergic type of reaction. Some health care workers who are allergic to latex are at risk when they are at work because protective gears such as gloves and a lot of medical supplies are made from latex materials. The abdomen can suffer allergic type of reaction to some people who wear elastic pants; Some people can be allergic to metallic buttons in jeans without them even knowing it. All they know is that their tummies are itching and still wear it. Those who wear elastic stockings, and articles made from rubber and leather who happen to be allergic with these types of materials may produce the symptoms. These sensitivity do not cause demonstrative skin changes in first contact but may produce specific skin changes when re-exposed to allergen. Primary reaction—acute or subacute, can be well demarcated redness. Subacute changes or reactions are characterized by plagues. Secondary reaction, which are chronic in nature, can be plague with lichenification.
Properly indicated logos and signs are seen on several products to ensure safety of the consumer or user.
A Patch Test is doen to detect hypersensitivity to a substance which is contact with the skin. Application to the skin in a non-irritating concentration of substances but with the use of test strips applied on the upper back or arm then removed after to see if there is redness or itchiness observed. When an object or agent is found to be a positive allergen, contact of this object to the skin should be avoided or minimized to prevent the symptoms from occurring.