Contact dermatitis is an itchy, inflamed rash caused by something that touches the skin. Sometimes the trigger directly irritates the skin; other times the immune system has developed an allergy to a substance that was previously tolerated.
Common triggers include soaps, cleaning products, fragrances, preservatives, metals, adhesives, gloves, hair products, cosmetics, topical medications, plants such as poison ivy, and workplace exposures.
Irritant vs. allergic contact dermatitis
Irritant contact dermatitis occurs when repeated or strong exposure damages the skin barrier. Frequent handwashing, sanitizers, detergents and wet work are common examples.
Allergic contact dermatitis is a delayed immune reaction to a specific allergen. Nickel, fragrance, preservatives, hair dye ingredients, adhesives and topical medications are frequent causes.
Poison ivy, poison oak and poison sumac
These plants contain urushiol, an oil that can cause allergic contact dermatitis. The rash may be intensely itchy and blistering. The fluid inside the blisters does not spread the rash, but urushiol remaining on clothing, tools, pets or other surfaces can cause new exposure.
How we evaluate contact dermatitis
The location and shape of the rash often provide important clues. We review skin-care products, medications, hobbies, work exposures and anything new that may have contacted the skin. When allergic contact dermatitis remains a concern, patch testing may be recommended to help identify a delayed skin allergy.
Contact dermatitis can resemble eczema, fungal infection, psoriasis or other rashes, so persistent or recurrent cases deserve a diagnosis rather than repeated trial-and-error treatment.
Treatment
- Avoidance: Identifying and avoiding the trigger is the most important long-term step.
- Skin-barrier care: Gentle cleansers, moisturizers and protection from repeated irritation help the skin recover.
- Prescription treatment: Topical anti-inflammatory medication is often used. More extensive or severe reactions may require additional treatment based on the examination and medical history.
- Poison ivy: Extensive blistering, facial swelling, genital involvement or severe symptoms should be evaluated promptly.
When to seek urgent care
Seek immediate medical care for trouble breathing or swallowing, significant facial or eye swelling, widespread blistering, fever, rapidly worsening pain, or other signs of a severe reaction or infection.
Related reading from Borealis
More information: American Academy of Dermatology: Contact dermatitis.
Schedule an evaluation
Appointments are available in Garden City, Syosset, and Bellerose, NY. Book Appointment or call (516) 246-8800.