Contact urticaria is localized color changes and swelling on the skin that appear immediately after coming into contact with a specific substance.
Contact urticaria can result from a variety of substances, like foods, preservatives, fragrances, and animal products. Latex gloves, cosmetics, skin creams, and sorbic acid (a food preservative) are the most common causes.
A urticaria rash can either be a nonimmune response to an external irritant, like stinging nettles, or an immune-related response to an allergen you’ve already had exposure to, such as latex gloves.
This article looks at contact urticaria in more detail, including its causes, risk factors, symptoms, and treatment.
What’s the difference between contact urticaria and contact dermatitis?
Contact urticaria is an immediate and short lived reaction to a certain substance, with symptoms typically clearing up within 24 hours.
Contact dermatitis appears hours or days after coming into contact with an irritant, and it may take several days or weeks to clear up.
There are two types of contact urticaria: nonimmunological contact and immunological contact. Each type has its own causes.
Nonimmunological contact urticaria is a mild, localized reaction to a skin irritant, like stinging nettles.
Immunological contact urticaria is an immune response to an allergen that you’ve already had exposure to. It commonly occurs in people who are predisposed to allergies such as eczema, asthma, and allergic rhinitis (hay fever).
The table below lists
| Potential causes of nonimmunological contact urticaria | Potential causes of immunological contact urticaria |
| fragrances and flavorings, such as Balsam of Peru and cinnamic acid | rubber latex, such as surgical gloves |
| food preservatives, such as sorbic acid | certain antibiotics |
| disinfectants, such as formaldehyde | certain metals, such as nickel |
| certain metals, such as cobalt | short-chain alcohols, such as denatured alcohol, propyl alcohol, and isopropyl alcohol |
| certain plants, such as stinging nettles and seaweed | polyethylene glycol (used in some laxatives) |
| certain medications and remedies, such as benzocaine, camphor, and witch hazel | plant proteins, such as vegetables and fruits |
| animal proteins, such as meat and seafood | |
| some enzymes, such as alpha-amylase and cellulase |
Anyone can get contact urticaria, but certain groups of people are at increased risk due to more frequent exposure to substances that can cause irritation.
In most of the following cases, people have had exposure to irritants over time, and their contact response is immune-related:
- Agricultural workers may be at higher risk due to their exposure to cow dander, grains, or feed.
- Bakers may be at higher risk due to flour, alpha-amylase, or ammonia persulfate exposure.
- Dentists may have a higher risk due to their use of latex gloves, epoxy resins, or acrylate.
- Food workers may be at higher risk from exposure to fish, shellfish, fruit, flour, or wheat.
- Hairdressers may have an increased risk due to their use of ammonia persulfate or latex.
- Medical and veterinary workers may also be at risk due to their exposure to latex.
Symptoms of contact urticaria appear rapidly, minutes to 1 hour after exposure to an irritant. They may include:
- localized burning, tingling, or itching at the contact area
- localized swelling or colored weals (marks), especially on the hands
- a rash that clears up by itself within 24 hours
In some cases, particularly in immunological contact urticaria, symptoms may occur in places other than the skin. These symptoms may include:
- wheezing
- runny nose and watery eyes
- lip swelling
- hoarse throat
- difficulty swallowing
- nausea
- vomiting
- diarrhea
- stomach cramps
- severe anaphylactic shock
Anaphylactic shock is a serious medical emergency
Anaphylactic shock can be life threatening. Call 911 immediately if you or someone with you is experiencing:
- swollen lips, mouth, tongue, or throat
- choking
- difficulty breathing
- confusion
- drowsiness
- dizziness
- fainting or unconsciousness
A doctor may be able to diagnose contact urticaria by reviewing your medical history and examining your rash.
They may also use the following tests to help confirm a diagnosis:
These tests can help confirm a diagnosis of contact urticaria, but they can’t determine whether it’s immunological urticaria or nonimmunological urticaria.
In most cases of nonimmunological urticaria, the rash clears up on its own once the irritant is no longer in contact with the skin.
Management focuses on avoiding the substance that causes the reaction, if you can, or finding a replacement for it. For example, you can use gloves to protect your hands from coming into contact with irritants, and you can swap latex gloves for nonlatex gloves if you have a latex allergy.
A doctor may also prescribe over-the-counter (OTC) antihistamines or topical corticosteroids for more severe or painful reactions.
People with immunological urticaria should note how their body responds to irritants. If you’ve experienced potentially life threatening reactions to certain allergens, for example, consider wearing a medical alert bracelet.
Contact urticaria is a fairly common skin condition that occurs after coming into contact with an irritant. Symptoms are typically localized skin color changes and swelling that clear up on their own within 24 hours.
In some cases, you may experience nonskin reactions, like wheezing, a runny nose, or watery eyes. More serious reactions, such as difficulty breathing or anaphylactic shock, are also possible.
The best form of management is to avoid contact with the irritant that causes the urticaria. A doctor may also prescribe OTC antihistamines or corticosteroids for symptom relief.