Contact dermatitis is an itchy and red rash which is caused when a certain substance comes in contact with the skin. This rash is not life-threatening or contagious, but can be very uncomfortable.
Contact dermatitis is caused by soaps, fragrances, cosmetics, jewelry or plants like poison oak or poison ivy. It can also be caused by exposure to certain substances at one’s workplace.
In order to treat contact dermatitis, the cause should be identified and avoided. Avoiding the causative substance helps the rash to clear up in two to four weeks.
Based on the cause, contact dermatitis can be divided into two types:
- Irritant contact dermatitis
- Allergic contact dermatitis
Irritant contact dermatitis:
This type of contact dermatitis occurs when the skin comes in direct contact with irritant substance which damages the skin and causes redness, burning sensation and itching. It may be caused if the skin has been exposed to a weak irritant for long durations or can be caused by exposure to a strong irritant for a short duration.
Common irritant substances include:
- Detergents and soaps
- Antiseptics and anti-bacterials
- Cosmetics and perfumes
- Lubricating oils used in machines
- Acids and alkalis
- Dust and soil
- Heavily chlorinated or hard water
- Plants such as spurge, Ranunculus, mustards and Boraginaceae
Exposure at work:
Irritant contact dermatitis can also be caused by exposure to irritants which are present at workplace. The common occupations where the irritants are present at workplaces include:
- Chemical workers
- Agricultural workers
- Hairdressers and beauticians
- Cooks and caterers
- Construction workers
- Health and social care workers
- Electronic and metal workers
- Mechanics and vehicle assemblers
- Machine operators
Allergic contact dermatitis:
This type of contact dermatitis occurs when the skin comes in contact with a substance which the body’s immune system is against to.
The common causes of allergic contact dermatitis include:
- Preservatives in cosmetics, hair dyes, fragrances
- Nail varnish hardeners
- Metals such as cobalt and nickel in jewelry
- Dyes and resins in the textiles
- Epoxy resins present in strong glues
- Some plants such as sunflowers, chrysanthemums, tulips, daffodils and primula.
Contact dermatitis occurs on skin areas where it has been exposed to the irritant substance. The signs and symptoms include:
- Severe itching
- Bumps or red rash
- Dry, scaly or cracked skin in chronic conditions
- Blisters, crusting and draining fluid
- Burning or tenderness, swelling
The following procedures are done to diagnose contact dermatitis:
- Physical examination and medical history: The physician may do a physical examination to identify the symptoms of contact dermatitis and may ask questions regarding the pattern and severity of reaction and the daily routine to identify the causative irritant.
- Patch test: Contact delayed hypersensitivity allergy test or patch test is done to check if the patient is allergic to something. This test is useful when the cause of rash is not apparent and the rash occurs often.
In this test, the suspected allergens are applied on the adhesive patches which are placed on the skin usually on the back. These patches are kept for two days during which it is required to keep the skin of back dry. Then the patches are removed and the physician checks for skin reaction.
The treatment of contact dermatitis involves the following options:
- Avoiding the causative agent: If a specific allergen or irritant has been identified which is causing the rash, then it is best to avoid that substance. Additionally the physician may give a list of substances which contain that allergen or irritant.
- Steroid creams: The physician may prescribe steroid creams to reduce the symptoms of the skin.
- Medications to repair skin: Medications such as calcineurin inhibitors pimecrolimus or tacrolimus available as ointments and creams can be applied to skin to repair the damaged skin. They are also useful in preventing the recurrence of contact dermatitis.
- Oral medications: The physician may prescribe oral drugs such as corticosteroids, antihistamines or antibiotics in severe cases to reduce the inflammation, itching and bacterial infection if any.
The following tips should be followed to prevent contact dermatitis:
- Avoid the allergens and irritants.
- Wash the skin immediately after having contact with rash causing substance.
- Wear gloves or protective clothing while working with irritating substances.
- Apply over-the-counter skin creams which contain bentoquatam to prevent or lessen the skin reaction to poison oak.
- Using moisturizer can help retain the skins moister and prevent it from cracking.
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