Contact Dermatitis Causes, Types, Symptoms, Diagnosis, Treatment, Prevention, Home Remedies

Contact Dermatitis Causes, Types, Symptoms, Diagnosis, Treatment, Prevention, Home Remedies

What is contact dermatitis?

Contact dermatitis is inflammation of the skin (rash) that may result when the skin is touched by chemicals or physical substances that cause an allergic or irritant reaction. Contact dermatitis can occur from exposure to many different compounds found both in the home and at work.

Contact Dermatitis Causes, Types, Symptoms, Diagnosis, Treatment, Prevention, Home Remedies
Contact Dermatitis

Culprits in everyday life include soaps, cosmetics, fragrances, jewelry, or plants such as poison ivy or poison oak. Some occupations involve exposure to substances that may cause contact dermatitis.

Successful contact dermatitis treatment consists primarily of identifying what's causing your reaction. If you can avoid that offending agent, the rash usually resolves in two to four weeks. Self-care measures, such as wet compresses and anti-itch creams, can help soothe your skin and reduce inflammation.

Causes and Types of contact dermatitis

Irritant contact dermatitis

This is caused by direct contact with a substance which irritates the skin. This is common and causes about 8 in 10 cases of contact dermatitis. It most commonly affects the hands. Irritant substances are those that can cause inflammation in almost everyone if they are in contact for long enough, often enough and in strong enough concentration. For example:

  • Detergents (washing-up liquid, soaps, bleach, etc). People who do a lot of cleaning are prone to irritant contact dermatitis.
  • Solvents (such as petrol), oils and other chemicals used in various places of work.
  • Acids and alkalis, including cement.
  • Powders, dust and soil.
  • Certain plants (for example, ranunculus, anemone, clematis, hellebore, mustards).
You can develop irritant contact dermatitis quickly from a single exposure to a strong irritant. For example, from contact with a strong chemical in a work situation. However, you may also develop irritant contact dermatitis because of repeated exposures to weaker irritants. For example, from a detergent that you use when washing up dishes regularly.

There is often a vicious circle. A patch of skin may become sore after being in contact with an irritating substance. This causes some skin damage. Once damaged, the skin is more easily affected by irritants. So, further contact, even with small amounts of the substance, may cause further inflammation and damage and so on.

Allergic contact dermatitis

This occurs when your immune system reacts against a specific substance. The substance is then called an allergen. You only need a small amount of allergen in contact with your skin to cause the rash.

You are not born with this type of allergy - you must have previously come into contact with the allergen which has sensitised your immune system. Once sensitised, your skin reacts and becomes inflamed when it comes into further contact with the allergen. This is why you can suddenly develop a skin allergy to something you have come into contact with many times before. It is not clear why some people become allergic to some substances and most people do not.

Many substances can cause an allergic contact dermatitis. Common ones include:

  • Nickel - this is the most common cause. Nickel occurs in many types of metal. For example: jewellery, studs in jeans and other clothes, bra straps, etc. So it is common to develop itchy red patches on the skin next to such things.
  • Cobalt - traces of this metal may be found in some jewellery.
  • Cosmetics - particularly perfumes, hair dyes, preservatives and nail varnish resins.
  • Additives to leather and rubber (in shoes, clothes, etc).
  • Preservatives in creams and ointments.
  • Plants - the most common culprits being chrysanthemums, sunflowers, daffodils, tulips and primula.
Sometimes the cause is not clear and you may need tests to find the cause.

When Skin Damage Causes a Rash

Some rashes look like an allergic reaction but really aren’t because your immune system isn’t involved. Instead, you touched something that directly hurt your skin. The longer that thing stayed on your skin, the worse the reaction. It’s called irritant contact dermatitis.

If you have eczema, you’re more likely to get this kind of a rash.

What are the symptoms of contact dermatitis?

Contact dermatitis symptoms can range from mild redness and dryness to severe pain and peeling that can be disabling.

Allergic contact dermatitis symptoms

  • Reddening of skin (either in patches or all over the body)
  • Intermittent dry, scaly patches of skin
  • Blisters that ooze
  • Burning or itching that is usually intense without visible skin sores (lesions)
  • Swelling in the eyes, face, and genital areas (severe cases)
  • Hives
  • Sun sensitivity
  • Darkened, "leathery," and cracked skin
Allergic contact dermatitis can be very difficult to distinguish from other rashes.

Irritant contact dermatitis

  • Mild swelling of skin
  • Stiff, tight feeling skin
  • Dry, cracking skin
  • Blisters
  • Painful ulcers on the skin
Symptoms vary depending on the cause of dermatitis.

When to see a doctor

See your doctor if:

  • You're so uncomfortable that you're losing sleep or are distracted from your daily routines
  • Your skin is painful
  • You're embarrassed by the way your skin looks
  • You suspect your skin is infected
  • You've tried self-care steps without success
  • You suspect that your dermatitis is job-related

Are certain occupations at greater risk?

Some occupations have more exposure to chemicals or substances that can result in sensitization and cause allergic contact dermatitis. These include dental workers, health care workers, florists, hairdressers, machinists, and photographers among many others.

How can I know if I have contact dermatitis?

If you have a skin rash that won't go away, visit your health care provider. If he or she suspects allergic contact dermatitis, patch testing may be performed. In this test, small samples of chemicals are placed on an area of skin on your back to see if a rash develops. There are no needles or pricking of the skin. These areas of the skin are then evaluated after 48 hours and again at 96 hours or one week.

The advantage of patch testing is that, if you are allergic to any chemical/product, the allergens can be identified, and your health care provider can effectively treat the rash with therapy and avoidance of the allergen(s). There are no tests that can be done for irritant contact dermatitis. Tell your health care provider about any irritating substances or chemicals that you regularly come into contact with (including cosmetics, lotions, and nail polish).

With either type of contact dermatitis, you can avoid substances you suspect and see if the rash improves.

How is contact dermatitis diagnosed?

The key to successful treatment of contact dermatitis is identifying what's causing your symptoms. Doctors rely on two chief strategies to determine the cause:

A thorough medical history and physical exam

Your doctor may be able to diagnose contact dermatitis and identify its cause by talking to you about your signs and symptoms, questioning you to uncover clues about the culprit, and examining your skin to note the pattern and intensity of your reaction.

A patch test (contact delayed hypersensitivity allergy test)

If the cause of your rash isn't apparent from your history and symptoms, or if your rash recurs often, your doctor may recommend patch testing. During a patch test, small quantities of potential allergens are applied to adhesive patches, which are then placed on your skin. The patches remain on your skin for two days before your doctor evaluates your response. If you're allergic to a particular substance, you develop a raised bump or a reaction limited to the skin just beneath the patch.

What is the treatment for contact dermatitis?

Treatment includes washing with lots of water to remove any traces of the irritant that may remain on the skin. You should avoid further exposure to known irritants or allergens.

In some cases, the best treatment is to do nothing to the area.

Emollients or moisturizers help keep the skin moist, and also help skin repair itself. They protect the skin from becoming inflamed again. They are a key part of preventing and treating contact dermatitis.

Corticosteroid skin creams or ointments may reduce inflammation. Carefully follow the instructions when using these creams. Overuse, even of low-strength over-the-counter products, may cause a skin condition.

Along with, or instead of corticosteroids, your health care provider may prescribe drugs called tacrolimus ointment or pimecrolimus cream to use on the skin.

In severe cases, corticosteroid pills may be needed. You will start them on a high dose, which is tapered gradually over about 12 days. You may also receive a corticosteroid shot.

Wet dressings and soothing anti-itch (antipruritic) or drying lotions may be recommended to reduce other symptoms.

How can I prevent contact dermatitis?

For allergic contact dermatitis:

  • Avoid contact with substances that cause the skin rash.
  • Wash any area that comes into contact with allergic substances.
  • Learn to recognize poison oak and poison ivy.

For irritant contact dermatitis:

  • Wear cotton gloves under rubber gloves for all wet work. Or, use petroleum jelly to protect the skin. Reapply the petroleum jelly two or three times a day and after washing your hands.
  • Avoid contact with substances that irritate the skin.
  • Use mild soaps.
  • Use hand creams and lotions frequently.

Home Remedies for Contact Dermatitis

Apply an anti-itch cream or calamine lotion to the affected area. A nonprescription cream containing at least 1 percent hydrocortisone can temporarily relieve your itch.

Take an over-the-counter antihistamine. A nonprescription oral antihistamine, such as diphenhydramine (Benadryl, others), may be helpful if your itching is severe.

Apply cool, wet compresses. Moisten soft white washcloths and hold them against affected areas to soothe your skin.

Avoid scratching whenever possible. Trim your nails and wear white cotton gloves at night. If you can't keep from scratching an itchy area, cover it with a dressing and bandages.

Take a comfortably cool bath. Sprinkle your bath water with baking soda or colloidal oatmeal — a finely ground oatmeal that's made for the bathtub (Aveeno, others).

Wear smooth-textured cotton clothing. This will help you avoid irritation.

Choose mild soaps without dyes or perfumes. Be sure to rinse soap completely off your body. And after washing, apply a moisturizer to protect your skin.

Outlook (Prognosis)

Contact dermatitis usually clears up without complications in 2 or 3 weeks. However, it may return if the substance or material that caused it cannot be found or avoided.

You may need to change your job or job habits if the disorder is caused by occupational exposure.