What Causes Contact Dermatitis?

What Causes Contact Dermatitis

Have you ever touched something and noticed your skin becoming red and itchy? This reaction could be contact dermatitis. Your skin is like a shield, protecting you from harm. When something harmful touches it, your skin reacts. In the case of what causes contact dermatitis, your immune system overreacts to the allergen or gets damaged by the irritant, leading to the rash symptoms. 

What is Contact Dermatitis?

Contact dermatitis is a common skin condition that falls under eczema and dermatitis. It affects 9% of the UK population and is the most common type of work-related skin condition. This condition is seen across all ages and backgrounds, making it a widespread skin issue.

There are two main types of contact dermatitis: 

  • Allergic Contact Dermatitis: This type occurs when your skin reacts to something it is allergic to. Common examples include nickel, a metal in jewellery, and certain plants like poison ivy.
  • Irritant Contact Dermatitis: This type is more common. It happens when your skin comes into contact with a harsh substance. Think of strong cleaning agents or acids. These irritants can damage your skin over time.

Unlike other skin problems, contact dermatitis is not caused by hormones or viruses inside your body; it is caused by external factors. It usually only affects the skin area that touches the irritant or allergen.

Who is More Likely to Get Contact Dermatitis?

Some people are more likely to get contact dermatitis than others. This can depend on several factors:

  • Job: People in specific jobs can get occupational contact dermatitis, like cleaning, hairdressing, or construction, if they often touch chemicals or allergens.
  • Skin Condition: Those with dry or sensitive skin are more prone.
  • History of Allergies: If you have other allergies, like hay fever, you might be more at risk.
  • Age: It can happen at any age, but certain types are more common in adults.
  • Past Skin Reactions: If you’ve had contact dermatitis, you’ll likely get it again.

Symptoms of Contact Dermatitis 

Contact dermatitis can cause several noticeable changes to your skin:

  • Rash: Often the first sign, appearing red and itchy.
  • Itching: A strong, sometimes unbearable urge to scratch.
  • Redness and Swelling: The affected area may become inflamed.
  • Blisters: In some cases, small blisters can form.
  • Dry, Scaly Skin: The skin may become dry and flaky over time.
  • Burning Sensation: Some people feel a burning on the skin.
  • Tenderness: The skin might be sensitive to touch.

Where on My Body Will I Have Symptoms of Contact Dermatitis?

The symptoms of contact dermatitis usually appear on the part of your body that touches the allergens and irritants. Common areas include:

  • Hands and Fingers: Especially if you’ve touched chemicals or allergens.
  • Face and Neck: Reaction to cosmetics or shampoos.
  • Arms and Legs: From plants like poison ivy or wearing certain fabrics.
  • Torso: Due to soaps, lotions, or detergents.

Remember, the location of the rash can give you clues about what caused it. For example, a rash on your wrist might be due to a watch or bracelet.

What Causes Contact Dermatitis?

Contact dermatitis happens when your skin reacts to certain substances. These can be things you touch every day or rare items.

When something your body doesn’t like touches your skin, your immune system responds. If you see your skin swell or become inflamed, it’s a sign your white blood cells are reacting to the allergen or irritant. This can lead to an itchy rash. The rash might show up in minutes with an irritant or take hours or days after exposure to an allergen.

What causes Allergic Contact Dermatitis?

Allergic contact dermatitis occurs when your immune system reacts to contact with an allergen. Here, your body mistakenly sees a harmless substance as a threat and responds to protect you: 

  • Nickel: Found in jewellery and metal items.
  • Poison Ivy, Poison Oak and Other Plants: Their sap triggers a reaction.
  • Cosmetics: Certain ingredients in makeup and skincare products.
  • Fragrances: Present in perfumes and scented products.
  • Latex: Used in gloves and some medical devices.

When these allergens touch your skin, your immune system releases chemicals. This causes the skin to become itchy and inflamed.

Are Allergic Reactions Immediate?

Only sometimes. The rash takes a few days to appear after contact with the allergen, and each person’s reaction time can vary.

What causes Irritant Contact Dermatitis? 

Irritant contact dermatitis is different from the allergic type. It’s caused by direct damage to your skin from a substance:

  • Detergents and Soaps: Harsh cleaning products can strip oils from your skin.
  • Solvents: Chemicals used in industry can irritate the skin.
  • Acids: Found in some industrial and household cleaners.
  • Prolonged Water Exposure: Long periods in water can remove protective skin oils.

When these irritants touch your skin, they can damage its outer layer. This leads to irritation and a rash. Unlike allergic contact dermatitis, this type doesn’t involve your immune system.

How is Contact Dermatitis Diagnosed? 

Figuring out if you have contact dermatitis involves a few steps. Doctors, like GPs or dermatologists, play a significant role in this.

  • Doctor’s Examination: First, your GP or pharmacist will examine your skin and ask about your symptoms. They’ll want to know what substances you’ve been in contact with. They will also discuss your health history and ask about past skin problems and allergies. This helps them understand your situation better.
  • Patch Test: Another part of diagnosing contact dermatitis is the patch test. Small amounts of different substances are placed on your skin in this test. Then, your skin is watched for a reaction. This helps to find out what you’re allergic to.
  • Track Symptoms: While you can’t diagnose contact dermatitis at home, you can keep track of your symptoms and what you touch. This info can help your doctor or pharmacist make a diagnosis.

How is Contact Dermatitis Treated?

The treatment for irritant contact dermatitis and allergic contact dermatitis is the same. There are two main differences in treatment: 

  1. Avoidance: If you know what’s causing your rash, try to stay away from it or limit your contact with it.
  2. Medications and Topical Creams: You might use anti-itch creams available without a prescription, creams or tablets for allergies like anti-histamines or corticosteroid creams. 


Emollients are treatments used for managing conditions like eczema and dermatitis, as they moisturise the skin and form a protective layer. There are various types, and finding the right one may involve trial and error. Options include:

Creams and lotions are less greasy, making them suitable for daytime use, while ointments are better for very dry areas and night use. If an emollient stops working or irritates your skin, consult your pharmacist for alternatives.

Topical Corticosteroids 

More intensive treatment might be needed during a severe contact dermatitis outbreak, where your skin is sore and inflamed.

Your GP or pharmacist can prescribe a topical corticosteroid as a cream or ointment for direct application to reduce inflammation. Mild steroid creams are also available for smaller affected areas.

The prescribed corticosteroid’s strength varies based on your dermatitis severity and the skin area. Prescriptions may include:

Always follow the instructions in the patient information leaflet accompanying your medication.

How to Prevent Contact Dermatitis 

Preventing contact dermatitis involves a few important steps:

  1. Identify and Avoid Irritants or Allergens: Know what substances cause your reactions and avoid them.
  2. Use Protective Clothing: Wear gloves or protective clothing when handling irritants. 
  3. Skincare: Keep your skin moisturised to protect its barrier. Use gentle, fragrance-free products.
  4. Stay Informed: Be aware of common allergens in your environment, especially at work. Wash your hands or skin if you come into contact with a known irritant. 
  5. Test New Products: Patch test new skincare or cosmetic products on a small skin area first.

Treat Contact Dermatitis with Click2Pharmacy 

At Click2Pharmacy, we offer a variety of treatments for contact dermatitis. Our range includes creams, moisturisers, and medications, both over-the-counter and prescribed by healthcare professionals. We understand the discomfort of contact dermatitis and strive to provide effective solutions. Visit our online Eczema and Dermatitis clinic for a selection that suits your specific needs, and enjoy the convenience of having your treatment delivered directly to you. We are committed to helping you manage your contact dermatitis effectively and comfortably.

Contact Dermatitis FAQS

What is the difference between Contact Dermatitis and Eczema?

Contact dermatitis and eczema are both skin conditions, but they are different:

  1. Cause: Contact dermatitis is caused by touching an irritant or allergen. Eczema, or atopic dermatitis, is often linked to genetics and is a chronic condition.
  2. Triggers: Eczema can be triggered by stress, temperature changes, and food. Contact dermatitis triggers are usually external substances.
  3. Symptoms: Both can cause itching and redness, but contact dermatitis is usually found where the skin touches the irritant.
  4. Treatment: Treatment can overlap, like using moisturisers and avoiding irritants. However, the approach might differ based on the underlying cause.

Is Contact Dermatitis contagious? 

Contact dermatitis isn’t contagious. You cannot catch it from someone else. It’s caused by your skin’s reaction to certain substances, not by a virus or bacteria that can be passed on. This misconception might come from seeing similar rashes on different people, especially if they’ve been in contact with the same irritant or allergen. If you’re around someone with contact dermatitis, you don’t need to worry about catching it. However, if you touch the same substance that caused their rash, you might experience symptoms of contact dermatitis if you’re sensitive to it.