Contact Dermatitis: Causes, Poison Ivy and Florida Plant Rashes, and How to Treat It

Written by Cherlie Joseph, MSN, FNP-BC · Medically reviewed by Naurah Gaspard, DNP, FNP-C, FNP-BC · Updated November 2026

Contact dermatitis is a red, itchy, sometimes blistering rash that shows up where your skin touched something that irritated it or that you are allergic to. Common culprits are soaps, nickel, fragrance, hair dye and plants like poison ivy. Avoiding the trigger and using an anti-inflammatory cream usually clears it in 2 to 3 weeks; widespread or facial rashes may need a prescription.

Irritant vs allergic contact dermatitis

	Irritant	Allergic
What happens	Something damages the skin directly	Your immune system reacts to a substance
Who gets it	Anyone, with enough exposure	Only people who are sensitized
Timing	Often soon after contact, or builds with repeated exposure	Usually 1 to 3 days after contact
Feels like	Burning, stinging, dry, cracked	Intense itch, often blisters
Typical example	Hand rash from frequent washing, sanitizer or cleaning products	Poison ivy, nickel in a belt buckle, fragrance, hair dye

Irritant contact dermatitis is the more common type. Both can look alike, and you can have both at once, especially on the hands.

Common causes

• Nickel: jewelry, watchbands, belt buckles, jeans snaps, phone cases
• Fragrance: perfume, lotion, soap, detergent, even "unscented" products that contain masking fragrance
• Preservatives: in wipes, shampoos and cosmetics
• Hair dye: especially dark dyes containing PPD; rash on the scalp edges, ears and neck
• Antibiotic ointments: neomycin and bacitracin are common allergens
• Rubber and latex: gloves, waistbands
• Acrylic nails and nail glue
• Irritants: water and soap, cleaning chemicals, hand sanitizer, cement, solvents

The shape of the rash is often the biggest clue: a rash under a ring, around the eyes from nail polish touching them, or in streaks from a plant.

Poison ivy and Florida plant rashes

Poison ivy, poison oak and poison sumac contain an oil called urushiol. Florida adds a few local relatives:

• Poisonwood grows in South Florida and the Keys and causes a similar blistering rash.
• Mango peel and sap contain related compounds. Some people get an itchy, blistering rash around the mouth or on the hands after peeling or biting into mangoes.
• Brazilian pepper, a common invasive shrub, can irritate skin in sensitive people.

What to know about plant rashes:

• Wash skin with soap and cool water as soon as possible after contact, and scrub under nails.
• Wash clothes, gloves, tools and pet fur, since the oil stays on surfaces.
• The rash often appears in lines or streaks, 1 to 3 days later, and can keep appearing for several days in areas that got less oil.
• Blister fluid does not spread the rash. Only the plant oil does.
• Most plant rashes last 1 to 3 weeks.

How contact dermatitis is treated

• Avoid the trigger. The rash will keep coming back until you do.
• Cool compresses and oatmeal baths ease itch and dry oozing blisters.
• Topical steroids. Over-the-counter 1% hydrocortisone helps mild rashes. Stronger prescription steroids work better for thick or blistering rashes on the body; the face and skin folds need gentler options.
• Moisturize with a thick, fragrance-free cream to repair the skin barrier, especially on hands.
• Oral antihistamines may help you sleep, though they do less for this kind of itch than for hives.
• Oral steroids are used for severe or widespread rashes, like poison ivy covering large areas or the face. They are usually tapered over 2 to 3 weeks, because shorter courses can let the rash rebound.

Skip antibiotic ointments and products with "-caine" numbing ingredients on the rash; they can cause their own contact allergy.

Finding a hidden trigger: patch testing

If a rash keeps coming back and the cause is not obvious, patch testing can help. A dermatologist or allergist tapes small amounts of common allergens to your back, then checks your skin over several days. Once you know your allergen, you can read labels and avoid it.

Frequently asked questions

How long does contact dermatitis last?

Once you avoid the trigger, most rashes clear in 2 to 3 weeks. Plant rashes like poison ivy last 1 to 3 weeks. If the trigger keeps touching your skin, it will not fully heal.

Is poison ivy contagious?

No. The rash and blister fluid do not spread to other people. The plant oil on skin, clothes or pets can, until it is washed off.

What is the fastest way to get rid of contact dermatitis?

Stop contact with the trigger, use cool compresses and an appropriate steroid cream, and moisturize. A widespread or facial rash may need a prescription, so it is worth an evaluation.

Sources

• American Academy of Dermatology: Contact dermatitis overview
• American Academy of Dermatology: Contact dermatitis causes
• American Academy of Dermatology: Contact dermatitis diagnosis and treatment

Keep reading

• Rash identifier guide
• Eczema in adults
• Hives: causes and treatment
• Browse all conditions and treatments A to Z

This article is for general education and is not a substitute for medical advice. Treatment, including any prescription, is decided by a licensed provider after reviewing your health history. OurTopClinic is not for emergencies; if you have a medical emergency, call 911. OurTopClinic serves adults located in Florida, New Mexico, Oregon and Washington. Learn more at ourtopclinic.com.