Contact dermatitis

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Overview

Contact dermatitis is an inflammatory eczematous skin disease. It is caused by chemicals or metal ions that exert toxic effects without inducing a T-cell response (contact irritants) or by small reactive chemicals that modify proteins and induce innate and adaptive immune responses (contact allergens).

Contact dermatitis is divided into irritant contact dermatitis and allergic contact dermatitis. Irritant contact dermatitis is a nonspecific response of the skin to direct chemical damage that releases mediators of inflammation predominantly from epidermal cells while allergic contact dermatitis is a delayed (type 4) hypersensitivity reaction to exogenous contact antigens. Immunological responses are due to the interaction of cytokines and T cells. In photo contact, allergic dermatitis lesions are confined to sun-exposed areas even though the allergen is in contact with covered areas.

Until recently it was believed that allergic contact dermatitis was rare, unfortunately, data indicate that it is very common and affects close to 20% of children. 

The good news is that the majority of cases of contact dermatitis are self-limited and managed with simple supportive measures. However, in some patients, the disorder is chronic and can significantly affect the quality of life.

Symptoms

Allergic contact dermatitis. This is reaction by your skin after coming into contact to some substance that you are allergic to. It is usually a rash that can be red and itchy and sometimes blister.

Signs and symptoms of contact dermatitis vary widely and may include:

An itchy rash.

Leathery patches that are darker than usual (hyperpigmented), typically on brown or Black skin.

Dry, cracked, scaly skin, typically on white skin.

Bumps and blisters, sometimes with oozing and crusting.

Swelling, burning or tenderness.

Causes

Contact dermatitis is caused by exposure to a substance that irritates your skin or triggers an allergic reaction. The substance could be one of thousands of known allergens and irritants. Often people have irritant and allergic reactions at the same time. Irritant contact dermatitis is the most common type.

Nickel, chrome, and mercury are the most common metals that cause contact dermatitis: Nickel is found in costume jewelry, and belt buckles. Watches, zippers, snaps, and hooks on clothing may also contain nickel. Chrome-plated items, which contain nickel.

The foods that are commonly associated with protein contact dermatitis include raw seafood, eggs, and flour, and less commonly, meat, vegetables, fruits, and spices. 1,2,4 Prick tests and scratch tests are diagnostic and show severe positive reactions in response to the causative foods.Irritant Contact Dermatitis should not spread. The irritant affects the area where it came in contact with the skin. If the rash spreads to other parts of the body, you may have an Allergic Contact Dermatitis reaction. This type of contact dermatitis is immune-related and can spread away from the site of the rash.

Risk factors

Risk factors for allergic contact dermatitis include age, occupation, and history of atopic dermatitis. Overall contact dermatitis is most common in people with red hair and fair skin. Women are more likely to develop contact dermatitis because of the use of jewelry and fragrances.

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Complications

Contact dermatitis can lead to an infection if you repeatedly scratch the affected area, causing it to become wet and oozing. This creates a good place for bacteria or fungi to grow and may cause an infection.

Asthma and hay fever. Eczema sometimes precedes these conditions. ...

Chronic itchy, scaly skin. ...

Skin infections. ...

Irritant hand dermatitis. ...

Allergic contact dermatitis. ...

Sleep problems.

Prevention

You can take the following steps to help prevent contact dermatitis:

Avoid irritants and allergens. ...

Wash your skin. ...

Wear protective clothing or gloves. ...

Apply an iron-on patch to cover metal fasteners next to your skin. ...

Apply a barrier cream or gel. ...

Use moisturizer. ...

Take care around pets.