Contact dermatitis

Overview

Contact dermatitis is a skin reaction that occurs when your skin comes into contact with certain substances. Most cases of contact dermatitis are caused by skin irritants, while others are triggered by allergens, leading to an allergic response. The reaction may not appear until 24 to 48 hours after exposure. Direct contact with an irritant can also cause contact dermatitis that is not an allergic reaction. Although itchy and uncomfortable, contact dermatitis is not contagious.

Contact dermatitis can be triggered by various substances, including cosmetics, fragrances, jewelry, and plants. Typically, the rash appears within a few days after coming into contact with these substances. Identifying and avoiding the substance responsible for the reaction is crucial for successful treatment, and doing so often leads to clearance of the rash within 2 to 4 weeks. In the meantime, soothing the skin with a cool, wet cloth and practicing self-care can help alleviate symptoms.

Symptoms

Contact dermatitis manifests as a skin reaction in the area that has come into direct contact with the triggering substance. For instance, if the skin brushes against poison ivy, the rash may appear along the affected leg. The onset of the rash can occur within minutes to hours after exposure, and its duration typically ranges from 2 to 4 weeks.

Contact dermatitis symptoms and signs can vary greatly and may include:

• Hyperpigmented leathery areas that are darker than usual, typically found on brown or black skin.
• An itchy rash.
• Dry, cracked, and scaly skin, usually observed in white skin.
• Bumpy skin that occasionally oozes and crusts, along with blisters.
• Inflammation, burning, or sensitivity.

Consult your doctor if:

• You have difficulty is sleeping or go on with your daily activities because the rash is too itchy.
• There is a strong or extensive rash.
• If the rash is severe or widespread.
• Your concern is the appearance of your rash.
• If the rash persists for more than three weeks without improvement
• The eyes, lips, face, or genitalia are affected by the rash.

Seek immediate medical care if you suspect a skin infection accompanied by symptoms like fever and the presence of pus oozing from blisters. Likewise, if you experience difficulty breathing after inhaling burning weeds, or if your eyes and nasal passages are painful following exposure to smoke from burning poison ivy, it is crucial to seek prompt medical attention. Additionally, if you believe that a substance you ingested has caused damage to the lining of your mouth or digestive tract, it is important to seek immediate medical care.

Causes

Contact dermatitis occurs when your skin comes into contact with a substance that either irritates it or provokes an allergic reaction. This substance can be any of numerous known allergens and irritants. It is common for individuals to experience both irritant and allergic reactions simultaneously.

• Irritant contact dermatitis: Is the most prevalent form of skin reaction that occurs when an irritant causes damage to the outer protective layer of the skin. While some individuals may react to potent irritants after a single exposure, others may develop a rash after repeated contact with even mild irritants like soap and water. Interestingly, some people can gradually build a tolerance to the substance over time. Typical irritants include solvents, rubber gloves, bleach and detergents, hair products, soap, airborne substances, plants, fertilizers, and pesticides.
• Allergic contact dermatitis: Occurs when your skin reacts to a substance that triggers an immune response. This reaction is specific to the area of your skin that came into contact with the allergen. Sometimes, the allergen can enter your body through food, flavorings, medication, or medical procedures, leading to a condition known as systemic contact dermatitis.

Repeated exposure to certain substances over many years can cause sensitization, where you develop an allergy to those substances. Even a small amount of the allergen can then trigger a reaction.

Common allergens that can cause contact dermatitis include nickel (found in jewelry and various items), medications like antibiotic creams, Balsam of Peru (used in perfumes, toothpastes, and flavorings), formaldehyde (found in preservatives and cosmetics), personal care products such as body washes, hair dyes, and cosmetics, plants like poison ivy and mango (containing a highly allergenic substance called urushiol), airborne allergens like ragweed pollen and spray insecticides, and certain products that cause a reaction when exposed to sunlight, such as some sunscreens and cosmetics.

Children can develop allergic contact dermatitis not only from common allergens but also from exposure to various items such as diapers, baby wipes, jewelry used in ear piercing, clothing with snaps or dyes, and other similar sources. These items can trigger an immune reaction in the child’s skin, leading to the development of allergic contact dermatitis.

Risk factors

People who engage in particular occupations and pastimes may be more susceptible to contact dermatitis. Examples comprise:

• Cleaners
• Construction workers
• Health care workers
• Machinists
• Mechanics
• Florists
• Food handlers or those who cooks food
• Workers in the agriculture sector
• Hair stylists and make-up artists
• Swimmers or scuba divers because of the rubber in their face masks or goggles