Allergic Contact Dermatitis - Causes, Symptoms, Diagnosis, and Treatment

Introduction:

Contact dermatitis is a skin rash that occurs when the skin is contacted with any allergic substance or material. Specific individuals remain allergic-free to those substances. Women are more affected than men and can equally affect children and older adults.

What Is Allergic Contact Dermatitis?

Allergic contact dermatitis or contact allergy is a red itchy rash that occurs 48 to 72 hours after contact with allergic substances (allergen). It is a hypersensitive response produced by the body to any specific allergen, which can be smaller in size. These rashes do not spread from person to person. It can occur in any body area and may resolve within weeks if it is not contracted with allergens.

Which Type of Hypersensitivity Is Allergic Contact Dermatitis?

Allergic contact dermatitis is a delayed-type (type 4) hypersensitivity reaction. These reactions can occur due to single or multiple times of exposure to the allergen.

What Causes Allergic Contact Dermatitis?

Thousands of allergens can cause skin inflammation or irritation. The most common among them are:

• Nickel is a metal in stainless steel, jewelry articles, dress zippers, and buttons that mainly cause allergic reactions.

• Certain substances are present in personal care products, like perfumes, soap, shampoo, cosmetics, etc.

• Pollen grains in the flowers spread in the air and cause allergic reactions.

• Medications such as topical creams mainly cause responses in older adults.

• Paraphenylenediamine (PPDA), present in hair dyes, can cause swelling eyes and face.

• Rubber: Tight gloves used by medical workers can cause itching skin allergies.

• Poison ivy found in certain plants can cause blisters (bumps) on the skin if contacted.

• Chromium compounds are found in cement paints.

• In children, a rash may develop due to specific diapers, clothes, sunscreen products, etc.

• Sun exposure: Allergic reactions occur in the skin area exposed to the sun and are called photoallergy.

Who Is More Prone to Contact Allergic Dermatitis?

Occupational-based allergens that the worker contact can cause severe skin reactions. Those include:

• Medical professionals who use latex gloves for a long time.

• Mechanics dealing with nickel and chromium-based products.

• Cosmetologists who deal with various personal care products.

• Florists, gardeners, painters, and constructors are also prone to contact allergies.

What Are the Signs and Symptoms of Allergic Contact Dermatitis?

• Red and itchy rash.

• Irritation on the skin, primarily along with the eyes and nose.

• The inflammation can be in streaks or round in shape.

• Swelling, most commonly eyelid swelling.

• Blisters or elevated lesions tend to ooze blood.

• Infection of these blisters may occur if not treated early.

• Dry and flaky skin.

• These symptoms are severe, affect daily activities, and last for weeks.

How to Diagnose Allergic Contact Dermatitis?

• Physical Examination: A complete assessment of the patient with detailed history regarding the onset of an allergic reaction, any previous history of allergy, the type of occupation, and the materials used will help determine the type of allergen and the measures to be taken to avoid such allergens.

• Patch Test identifies the type of allergen that causes skin irritation. The dermatologist mainly suggests that the rashes are severe and recurring. In this test, the skin is exposed to many patches containing allergens. The patches are removed after 24 to 48 hours to check for any skin reaction.

• ROAT test: In this test, a suspicious allergen is directly applied several times on a small sensitive area of the skin. Repeated open application (ROAT) test is usually used to identify any allergy due to cosmetic products like moisturizers, perfumes, etc. The area mostly preferred for this test is the inner side of the upper arm.

• Skin Scraping: The dermatologist scraps the lesion or rash, and it is sent for microscopic examination and culture to identify any fungal infection.

• Dimethylglyoxime is a compound used to test the presence of nickel that causes allergy.

What Is the Differential Diagnosis?

The following diseases have clinical features similar to that of allergic contact dermatitis:

• Irritant contact dermatitis occurs due to irritation or injury to the skin caused by irritants like acid, soaps, and detergents. It also causes red skin rashes.

• Contact urticaria: Skin reactions like flaring and redness occur immediately after contact with a specific allergen. Whereas allergic contact dermatitis occurs after days of exposure.

• Tinea corporis is an infection caused by fungus leading to round rashes on the skin.

• Other skin conditions like scabies, psoriasis, etc

How to Treat Allergic Contact Dermatitis?

The various medications used in treating allergic contact dermatitis are:

• Topical corticosteroids are given if the symptoms are mild, and in severe skin rashes, oral corticosteroids like Prednisolone are helpful.

• Antibiotics can be prescribed to treat any infection of the rashes.

• Moisturizers and soothing lotions are also suggested to prevent skin dryness and relieve itching.

• Dressing the blisters that ooze out blood prevents further injury and infections.

• Topical calcineurin inhibitors (Tacrolimus) ointment is also beneficial. It is used in patients who do not respond well to topical steroids.

• Antihistamines are suggested in patients with symptoms that disturb sleep.

What Measures Are to Be Taken for Prevention?

• Identify and avoid the substances that cause allergic reactions. It is an essential criterion to prevent such rashes.

• Be away from chemicals and preservatives.

• Use mild soaps and cleansing agents that are fragrance-free.

• Wash your hands at regular intervals. Washing clothes with warm water after any contact with the allergen should be done.

• Ivyblock (Bentoquatam) lotion, which is available over the counter, can be applied to prevent allergies to poison ivy. Use moisturizers and creams regularly.

• Natural alternatives like Henna for hair coloring rather than hair dyes.

• Consult your dermatologist for alternate topical medications if any other lead to allergic reactions.

• Wear face shields, gloves, and other protective clothes while contacting any chemical substances.

Conclusion:

Skin rashes may look severe and bothersome, but they are treatable. Strictly avoiding exposure to allergens is the crucial goal in preventing contact dermatitis. Visit the dermatologist below for appropriate diagnosis and management of any skin irritation or inflammation.