When a person’s skin comes into contact with an irritating substance, they may develop an itchy or burning rash. This reaction is contact dermatitis.
Contact dermatitis is an inflammatory skin condition that results from contact with an irritating substance. Chemicals, heat, and substances that a person may be allergic to can all cause contact dermatitis.
This article outlines the types of contact dermatitis, their appearance, what may trigger them, and what a person can do to treat or prevent occurrences.
There are several common types of contact dermatitis. These typically vary depending on the agent involved.
Irritant contact dermatitis
Irritant contact dermatitis is the most common type of contact dermatitis and accounts for about 80% of all cases.
Many external factors may cause irritant contact dermatitis, including irritating chemicals, friction, and heat. Repeated exposure to weak irritants may also cause irritant contact dermatitis.
A person with irritant contact dermatitis
Allergic contact dermatitis
Allergic contact dermatitis occurs when the immune system produces an allergic reaction to a substance or chemical.
According to a 2018 study, exposure to nickel is the most common cause of allergic contact dermatitis in the United States, accounting for 17.5% of cases.
Many everyday products contain preservatives and other substances that can cause allergic reactions. As a result, many people may not be aware of what exactly is causing their allergic reaction without a diagnosis.
Occupational contact dermatitis occurs in certain professions where the workers may have frequent exposure to irritants or allergens, such as rubber, latex, or chemicals.
People who may experience occupational contact dermatitis include healthcare workers, hairdressers, and cleaners, among others.
Photocontact dermatitis occurs when a person comes into contact with a substance and sunlight at the same time. These irritants or allergens may be external, such as some sun lotions, or the result of ingested medications.
In photocontact dermatitis, exposure to sunlight is necessary to trigger the irritant or allergic reaction.
In nearly all cases of contact dermatitis, a rash will develop after exposure to an allergen or irritant. This rash may appear red on lighter skin tones, while on darker skin tones, it may appear dark brown, purple, or gray.
In most cases of contact dermatitis, the rash will be discolored and itchy, and it may sting. If exposure to an irritant or allergen continues, the skin may harden.
Additionally, contact dermatitis may lead to:
Triggers will vary from person to person and according to the type of contact dermatitis. As a result, a person needs to identify their triggers to avoid contact with the substance in the future.
The following are some of the most common triggers for contact dermatitis:
- nickel or gold jewelry
- fragrances in soap and perfumes
- isothiazolinones — preservatives in cosmetics
- poison ivy, poison oak, and poison sumac
- medications that people apply to the skin
- citrus fruit
- hair dye
Toxic or corrosive substances may lead to irritant contact dermatitis. A person may encounter these as part of their profession or at home.
Common chemical irritants include:
- pepper spray
- hand sanitizer
- battery acid
- drain and other cleaners
However, irritant reactions are not limited to toxic or more corrosive substances.
As mentioned, photocontact dermatitis requires the presence of an irritant and exposure to sunlight.
Examples of irritants that may react to sunlight include:
- shaving cream
- sun lotion or tanning oils
- topical steroids, in rare cases
- certain medications
In most cases, the rash and other reactions
However, the rashes that contact dermatitis causes may take time to heal after the initial exposure ends. This will naturally take longer if irritants damage the skin.
As a result, people can treat and manage most cases of contact dermatitis by avoiding contact with known irritants.
Should the symptoms of contact dermatitis cause discomfort, a person may be able to treat them with home remedies or over-the-counter (OTC) treatments, including:
- anti-itch ointments for the infected skin
- oatmeal baths, or similar
- antihistamine drugs
In severe cases, a person may need to see a dermatologist, an allergist, or another healthcare professional. They can prescribe ointment, creams, or prescription drugs to treat contact dermatitis.
In most cases, prevention is as simple as
However, a person may not know what caused the reaction. For example, preservatives in cosmetics are a common cause of contact dermatitis that may not be easily identifiable.
A dermatologist may be able to identify the allergen or irritant causing a person’s dermatitis. They may do so by assessing a person’s medical history and lifestyle habits or performing patch testing.
Contact dermatitis causes inflammation of the skin. It results from contact with an irritating substance and can lead to an itchy rash or even blisters.
A person may also experience contact dermatitis due to an allergic reaction to a substance, such as a preservative in skin care products or a certain plant. Chemicals and other corrosive agents may also cause contact dermatitis.
In rare cases, a combination of an irritant and sunlight exposure may cause a rash. Medical professionals refer to this as photocontact dermatitis.
A dermatologist or allergist may assist in determining the cause of a person’s contact dermatitis if it is not apparent.
In general, people can treat contact dermatitis by avoiding known irritants. They may also manage the symptoms with OTC medications and creams.