Contact dermatitis

Contact dermatitis is an itchy rash that occurs when your skin comes into direct contact with a substance or has an allergic reaction to it. Although the rash isn't contagious, it can be very uncomfortable.

Many substances can trigger contact dermatitis, such as cosmetics, fragrances, jewelry, and plants. The rash typically appears within days of exposure.

To effectively treat contact dermatitis, it's crucial to identify and avoid the substance causing your reaction. If you steer clear of the irritant, the rash usually clears up within 2 to 4 weeks. You can soothe your skin with a cool, wet cloth and follow other self-care steps.

Symptoms

Contact dermatitis manifests on the skin that has directly encountered the irritating substance. For instance, a rash might appear on a leg that brushed against poison ivy. It can develop within minutes to hours of exposure and may last 2 to 4 weeks.

Common signs and symptoms include:

• An itchy rash
• Leathery patches that are darker than usual (hyperpigmented), especially on brown or Black skin
• Dry, cracked, scaly skin, especially on white skin
• Bumps and blisters, sometimes with oozing and crusting
• Swelling, burning, or tenderness

When to See a Doctor

• The rash is extremely itchy and interferes with sleep or daily activities
• The rash is severe or widespread
• You are concerned about the appearance of the rash
• The rash doesn't improve within three weeks
• The rash affects the eyes, mouth, face, or genitals

Seek immediate medical care if:

• You suspect your skin is infected (signs include fever and pus oozing from blisters)
• You have difficulty breathing after inhaling burning weeds
• Your eyes or nasal passages hurt after inhaling smoke from burning poison ivy
• You believe an ingested substance has harmed the lining of your mouth or digestive tract

Causes

Contact dermatitis results from exposure to a substance that irritates your skin or triggers an allergic reaction. This substance could be one of thousands of known allergens and irritants. Some people may experience both irritant and allergic reactions simultaneously.

Irritant Contact Dermatitis

This is the most common type, occurring when an irritant damages your skin's outer protective layer. Some people react to strong irritants after a single exposure, while others may develop a rash after repeated exposure to even mild irritants, such as soap and water.

Common irritants include:

• Solvents
• Rubber gloves
• Bleach and detergents
• Hair products
• Soap
• Airborne substances
• Plants
• Fertilizers and pesticides

Allergic Contact Dermatitis

This occurs when a substance triggers an immune reaction in your skin. It often affects only the area that came into contact with the allergen but can also be triggered by something that enters your body, such as food, medicine, or through medical procedures.

Common allergens include:

• Nickel (used in jewelry, buckles, and many other items)
• Medications (e.g., antibiotic creams)
• Balsam of Peru (found in many products like perfumes, toothpastes, and flavorings)
• Formaldehyde (used in preservatives, cosmetics, and other products)
• Personal care products (e.g., body washes, hair dyes, cosmetics)
• Plants (e.g., poison ivy, mango)
• Airborne allergens (e.g., ragweed pollen, spray insecticides)
• Products that cause reactions when exposed to the sun (photoallergic contact dermatitis)

Children may develop allergic contact dermatitis from exposure to diapers, baby wipes, jewelry used in ear piercing, clothing with snaps or dyes, and other common items.

Risk Factors

Certain jobs and hobbies can increase the risk of contact dermatitis, including:

• Agricultural workers
• Cleaners
• Construction workers
• Cooks and food handlers
• Florists
• Hair stylists and cosmetologists
• Healthcare workers (including dental workers)
• Machinists
• Mechanics
• Scuba divers and swimmers (due to rubber in face masks or goggles)

Complications

Repeatedly scratching the affected area can lead to an infection, as it creates a suitable environment for bacteria or fungi to grow.

Prevention

To help prevent contact dermatitis:

• Avoid known irritants and allergens. For jewelry, use hypoallergenic materials like surgical steel or gold.
• Wash your skin immediately after contact with irritants like poison ivy using mild, fragrance-free soap and warm water. Also, wash any clothing or items that may have come into contact with the allergen.
• Wear protective clothing or gloves when handling irritating substances.
• Use an iron-on patch to cover metal fasteners next to your skin.
• Apply barrier creams or gels to protect your skin.
• Regularly use moisturizers to keep your skin hydrated.
• Bathe pets that may have come into contact with allergens like poison ivy.