Contact Dermatitis

Contact dermatitis is a result of external substances contacting the skin producing either an irritant dermatitis or an allergic contact dermatitis. There is also a type of contact dermatitis that requires an allergen of irritant to contact the skin at the same time and as well as light exposure.

Types Of Contact Dermatitis:

Irritant Dermatitis:

• Contact with a strong acid or alkali

• Repeated contact with a substance, which slowly breaks down the skin barrier, an example of this occurrence is excessive hand washing
• Individuals with a tendency to eczema are more prone to chronic irritant dermatitis
• This is most frequently seen on the hands

Allergic Contact Dermatitis:

This is an allergic reaction to a substance that has contacted the skin causing inflammation with redness, swelling, blisters of varying size, accompanied by itching. The chemical is usually a small molecule, which combines with a protein and is presented to lymphocytes in the skin. These lymphocytes become sensitized and produce a dermatitis reaction localized in the skin. The diagnosis is made from a history and examination of the skin. Detection of the allergen is conducted by performing allergy tests called patch tests. Discs containing the suspected allergens are placed against the skin for a 48 hour period.

• Nickel (metal,alloys)
• Fragrances (perfume)
• Balsam of peru (fragrance)
• Colophony (resin/glues)
• Tixocortol (cortisonecream)
• Kathon CG (antimicrobial in cosmetics)
• Cobalt (metal)
• Chrome (metal)
• Phenelynediamine (rubber, dyes)
• Black rubber mix (rubber chemicals)
• Epoxy resin (plastics)
• Quaturnium15 (cosmetics-antimicrobial)
• Parabens (preservative)

Special patch test trays are created for specific occupations that are known to cause allergy induced contact dermatitis. These occupations include bakers, hairdressers, and those that involve cutting oils, plants, textiles, and photographic chemicals.

• Identify and avoid the allergen with the help of patch testing
• Treat the dermatitis and help the skin recover

Photoallergy:

A substance does not become allergic until it has contact with the skin in the presence of ultraviolet light. The most common reaction of this kind is to sunscreens, and some pesticides. Some patients react to airborne allergens, such as that seen with a group of plants called Compositae. Special tests called photopatch tests are required to confirm the diagnosis.

Back to What Looks Like Rosacea Index   |   Top