Allergic Dermatitis: What is it? Types, Causes, Symptoms, Diagnosis and Treatment

The rash produced is red and itchy, but it is not contagious or a serious condition, although it is uncomfortable for the patient.

Contact dermatitis occurs when a person develops a rash from being in contact with certain substances.

This irritation or allergic skin reaction causes inflammation of the skin and is known as contact dermatitis.

The cause of contact dermatitis can be found in everyday things, such as jewelry, soaps, fragrances, cosmetics, plants (poison oak or poison ivy), among others.

Certain occupations where the person is exposed or works with certain substances can also cause contact dermatitis.

Treatment consists of identifying the cause and avoiding the causes for which the rash usually resolves in 2 to 4 weeks.

Other measures, such as anti-itch creams and wet compresses, help soothe the skin and reduce inflammation.

Types and causes of contact dermatitis

Depending on the cause, contact dermatitis is divided into two groups:

Irritant contact dermatitis

This is the most common contact dermatitis and occurs when the outer protective layer of the skin is damaged by certain substances, such as chemical solvents, cosmetics, harsh soaps, deodorant, etc.

The skin has dry, red, itchy patches commonly found on the face, hands, and fingers.

The severity of the condition depends on the duration of the exposure and the strength of the offending agent.

Strong irritants like acids or bleach can cause a reaction after being exposed to it just once.

Allergic contact dermatitis

It occurs when an individual who is allergic to a particular substance comes into contact with it, this leads to an immune reaction in the skin that produces red bumps and rashes.

In severe conditions, there is blistering as well.

Some of the allergens can be: hair dyes, metals such as nickel, natural rubber, jewelry, cosmetics, perfumes, and plants such as poison oak and ivy.

Once an allergy to a specific agent is formed, then the person will be allergic to that substance for their entire life. Even a small exposure will result in a reaction.

Photoallergic contact dermatitis

There are some substances that cause allergic contact dermatitis when after its application they are exposed to sunlight.

Common substances that cause this reaction are some ingredients found in sunscreens and ointments that contain non-steroidal anti-inflammatory drugs.

Certain oral medications, such as hydrochlorothiazide, can also cause a skin reaction caused by exposure to sunlight.

This is known as photosensitivity and looks like photo allergic contact dermatitis.

Most common dermatitis-causing substances

Some of the most common allergens or irritants are:

  • Nickel
  • Poison ivy.
  • The Oak.
  • The nuts.
  • Los anacardos.
  • Some topical antihistamines .
  • The antibiotics.
  • Antiseptics.
  • Flavorings.
  • Fragrances.
  • Soaps.
  • Strong detergents.
  • Skin cleansers.
  • The cosmetics.
  • The deodorant.
  • Some textiles for clothing and shoes.
  • Household cleaning substances.
  • Latex (natural rubber).
  • The costume jewelery.
  • The fuels.
  • The dyes.
  • The cement.
  • Industrial solvents.
  • Paper dust, sawdust, among others.

Airborne substances such as insecticidal sprays can cause contact dermatitis.

Symptoms of contact dermatitis

  • Presence of red rash, patches and bumps.
  • Itch.
  • Red spots that are dry, fissured, and resemble a burn.
  • Blistering in severe reactions, draining fluid and forming scabs.
  • There may be pain or tenderness to the touch.

Serious symptoms of contact dermatitis

  • If the condition is affecting daily life activities.
  • If there is an infection with drainage of pus.
  • If there is extreme pain.
  • If the person feels embarrassed because of the rashes and it affects their self-esteem.
  • If the dermatitis is related to the patient’s occupation.
  • If conventional treatment fails.

If the rash is severe and persistent in nature and the patient continually scratches it, then it could lead to other complications, such as neurodermatitis (lichen simplex chronicus) and bacterial or fungal infection of the skin.

So it is important to seek treatment if symptoms get worse.

Diagnosis for contact dermatitis

  • Medical history and physical exam.
  • Delayed hypersensitivity allergy test (patch test) to determine what substance the patient is allergic to.

Treatment for contact dermatitis

The best treatment for contact dermatitis is prevention.

Attempts should be made to identify the cause or the allergen or irritant that is responsible for the condition and avoid your exposure to it.

Some treatments include:

  • Applying anti-itch creams and wet compresses helps with itching and redness.
  • Hydrocortisone creams and calamine lotion also help relieve itching and redness.
  • If the rash does not resolve with medication, then the doctor may prescribe stronger medications.
  • In severe cases, oral corticosteroids and antihistamines are prescribed to reduce itching and inflammation.
  • Rashes should never be scratched, as this could lead to infection.
  • Keeping your nails trimmed and wearing cotton gloves when sleeping is a good thing to do.
  • Wearing cotton clothing that has a smooth texture helps prevent irritation.
  • Always use mild soaps, which do not have perfumes or dyes. You should always rinse soap completely from your body after a bath.
  • Use an unscented moisturizer after bathing.
  • Mild, fragrance-free laundry detergents should always be used.
  • Protective gear should always be worn when at work.
  • Mixing a few tablespoons of baking soda or oatmeal in the water from the last rinse in your daily bath can provide temporary relief.