Some people just can’t stand to be in contact with a few harmless things like pets, jewelry, makeup, or soap, known as contact dermatitis. Similar to atopic dermatitis they also break out in rashes and severe itchy and burning sensation followed by drying, crusting, and peeling of the skin—however the reaction may not show up until after several days.

Mechanism of the reaction

Contact dermatitis is a delayed hypersensitivity reaction characterized by inflammation of the skin as a result from direct skin contact with irritants or allergens. There are four basic types: allergic, irritant, phototoxic and photoallergic.

Primary exposure to allergens such as cosmetics, adhesive tape, medications, nickel, detergent, poison oak results in sensitization. Re-exposure causes a hypersensitivity reaction where sensitized T cells near the site react with the allergen. These cells secret lymphokines,a protein responsible for the attraction and activation of macrophages. Macrophages then release lysozymes causing tissue damage. The symptoms that occur include itching, redness, swelling at the site of contact, and raised lesions or blisters that eventually crust and peel and may last for days or weeks. Repeated reactions may lead to skin color changes and thickening. The reaction is usually localized unless the area becomes infected and causes systemic infection.

Skin sensitivity may develop after brief or prolonged periods of exposure, and the reaction may appear days, hours, or even weeks after the sensitized skin has been exposed.

What your doctor can do for you

The affected area needs to be assessed, and a careful history of exposure helps in determining the condition. Skin patch tests may be performed if the patient has no idea of the causative material. Topical corticosteroids in the form of creams are prescribed too decrease the inflammation. Oral forms are needed if the reaction covers a large area. Sometimes, antihistamines may also be used.

What you can do

• Poison ivy, sumac, and oak are the most common allergens for contact dermatitis. The best thing to prevent eruptions is to ferret out the cause. The doctor can do this for you, but it’s best to know this by yourself. A lot of products like nickel might have the same constituent with the one that caused you the condition.
• Once you have determined the allergen/irritant, protect your skin by wearing gloves while washing dishes, gardening, and so on.
• As much as possible, avoid scratching as this could lead to infecting the site.
• Soothe the area affected by applying cool compress over the area. Larger areas may need a soak in a colloidal bath (with oatmeal or baking soda).
• Apply calamine lotion to relieve the itch.