What is Contact Urticaria?
Contact urticaria, or CU, is a type of skin reaction that shows up as a temporary bump and redness. This reaction happens within 10 to 60 minutes after coming into contact with whatever caused it, and it completely fades away within a day. The condition, first identified by Alexander Fischer in 1973, falls under the category of acute urticaria, a type of hives that lasts for less than six weeks.
What Causes Contact Urticaria?
The likelihood of developing contact urticaria (CU) can be higher if the outermost layer of the skin is disrupted due to mutations in the filaggrin gene or exposure to substances that irritate the skin. There are several substances linked to the development of CU, which we will list later. Certain jobs put people at a higher risk of developing CU, including healthcare, laboratory work, farming, hairdressing, cosmetics, the chemical industry, cleaning, construction, catering, cooking, electronics, machinery, and metal production.
Risk Factors and Frequency for Contact Urticaria
Chronic urticaria (CU), an issue characterized by long-term skin reactions, often goes unnoticed in the general population because of lower diagnosis rates. However, professional studies reveal some statistics:
- For people who work in certain jobs, the prevalence of the condition is around 0.4%.
- Actually, about 30% of all job-related skin diseases are chronic urticaria.
- The prevalence range of latex-related CU is somewhere between 5% to 10%.
- Among healthcare workers, 5% to 13% have been found to be sensitive to natural rubber latex (NRL).
- Common items like natural rubber latex (NRL), cosmetics, skin creams, and sorbic acid are frequent causes.
- From 1989 to 1994, the incidence of chronic urticaria more than doubled, as suggested by the Finnish Registry.
- Common allergens that can cause the issue are cow dander, NRL, flour, and grains.
Signs and Symptoms of Contact Urticaria
When identifying Chronic Urticaria (CU), a detailed history and medical examination are crucial. Exchange of patient history and a thorough examination aid in making an accurate diagnosis.
During the clinical history phase, besides gathering general information, the healthcare provider should pay extra attention to any exposure to possible causes found in food, everyday environments, cosmetics, and personal care products. The timeline of exposure and symptom development, as well as when symptoms subside, is vital. It’s also important to ask about factors that can worsen or relieve symptoms, such as temperature changes, physical pressure, or medications. Specific skin reactions, like wheals, tingling, burning, or itching, and the course of the symptoms should be discussed. A history of atopy in the individual or their family can be a hint towards an IgE-mediated Intensive Care Unit (ICU). Certain proteins can cause eye irritation, runny nose, or asthma symptoms when they come into contact with the conjunctiva or respiratory tract mucosa; for example, flour. Other whole-body symptoms can include stomach ache, mouth itching when ingesting food (oral allergy syndrome), and diarrhea when in contact with the gastrointestinal tract’s mucosa.
During the physical examination, the most common sign of CU is a wheal and flare reaction and swelling from urticaria. Patients with CU can show symptoms of hives (urticaria) or skin inflammation (eczema). The urticarial response may appear as reddish swelling with surrounding paleness. However, in a non-IgE-mediated ICU (NICU) reaction, the typical wheal and flare response may be missing. The skin examination should focus on the lesion site, pattern, size, shape, and how they merge, along with swelling of a blood vessel, redness, paleness, skin writing disease (dermographism), and hives caused by inflammation of blood vessels (urticarial vasculitis). CU wheals do not usually cause blisters or scaling, are transient, and do not leave any lasting skin changes or pigmentation. The signs can vary between an active outbreak versus a period of calmness (quiescence).
Podiatric Contact Dermatitis (PCD) typically appears as reoccurring skin inflammation with urticarial plaques or blisters. These blisters can form quickly and advance to red scaly or red vesicular lesions. Inflammation around the nails with swelling around the nail bed and redness can be a sign of PCD.
Testing for Contact Urticaria
In addition to your medical history and a physical examination, your doctor may use in-vivo and in-vitro tests to help make a diagnosis. Skin tests are typically quick to perform and generally safe.
In-vivo tests are commonly used to diagnose Chronic Urticaria. These should be supervised by a healthcare professional who is prepared to handle a severe allergic reaction. Reactions can happen within 15 to 20 minutes or may be delayed. If the initial testing on fresh skin comes back negative, the doctor may test the skin where you’ve had a past reaction. The results need to be carefully reviewed in combination with your symptoms. Some medications and exposures to ultraviolet light can affect the test and may lead to false-negative results, so it’s suggested that you stop using antihistamines 48 hours before testing.
A variety of in-vivo tests are used, including the prick test, open test or skin provocation test, chamber or patch test, scratch test, and dimethylsulfoxide (DMSO) test. Each test has its own procedure and is meant to observe the skin’s reaction to certain substances or allergens. It’s important to note that the reaction to these tests should always be observed under medical supervision due to the risk of severe allergic reactions, such as anaphylaxis.
As for in-vitro testing for Chronic Urticaria, this typically involves looking for specific disease-fighting antibodies known as IgE in the patient’s blood. Other laboratory tests might include a complete blood count, erythrocyte sedimentation rate, C-reactive protein, basic metabolic panel, thyroid auto-antibodies, anti-nuclear antibody level and complement levels. These tests help rule out other conditions that might be causing your symptoms, like systemic illness, chronic idiopathic urticaria, autoimmune diseases, infections, and more.
Treatment Options for Contact Urticaria
Avoiding the substance that causes an allergic reaction is the best way to manage the condition. This requires educating patients about proteins that can trigger allergies and advising them to avoid them if they experience symptoms.
If contact with the allergen can’t be avoided at work, safety measures such as wearing gloves, using skin creams or lotions, and wearing cotton liners should be implemented.
For those allergic to natural rubber latex (NRL), substitutes like nitrile, neoprene, or polyvinyl chloride gloves should be used. To reduce the number of cases caused by NRL, some healthcare facilities have prohibited the use of powdered NRL gloves. If a patient has a latex allergy, they should avoid all products containing latex.
The first line of treatment for ICU typically involves second-generation H1-receptor blockers, such as diphenhydramine, hydroxyzine, loratadine, or desloratadine. Other drugs that can inhibit inflammation like montelukast, zafirlukast, and zileuton can also help.
Aspirin and NSAIDs (non-steroidal anti-inflammatory drugs) are the first choices for managing NICU.
Patients should always have access to self-administered epinephrine pens in case of emergencies.
Steroids can also be used as a second line of treatment to help prevent anaphylactic reactions.
In severe cases, immunosuppressive drugs such as cyclosporine and methotrexate can be used.
Exposure to Ultraviolet A and B light can also help inhibit NICU reactions, with effects lasting up to two weeks after treatment. This method can inhibit skin sites that are not directly exposed to light.
Research into the use of subcutaneous immunotherapy in managing CU shows promising results. For example, a study on 41 bakers with wheat protein allergies who received subcutaneous immunotherapy showed improvement in managing CU. This method also proved effective in workers sensitized to NRL, with improvement seen in skin reactivity.
An accelerated (two or four-day) sublingual desensitization to NRL also showed significant improvements in symptom severity.
What else can Contact Urticaria be?
Urticaria and angioedema, which are skin conditions commonly known as hives and swelling respectively, can often be linked with serious body-wide illnesses such as autoimmune diseases, hormonal problems, cancer, and blood diseases. Chronic unexplained hives are generally connected to autoimmune diseases.
Anaphylaxis, a severe allergic reaction, can also manifest as widespread hives along with other symptoms impacting the whole body.
Chronic urticaria, which is a term for long-lasting hives, shares common characteristics with allergic skin rash, angioedema (swelling in deeper layers of the skin), skin lesion due to light scratching, and skin inflammation caused by irritation.
Hand hives caused by gloves are a type of hives resulting from the friction during putting on and taking off the gloves. This condition needs to be distinguished from chronic making distinguish from chronic hives and allergic reaction to natural rubber latex (NRL).
Specific forms of hives such as those caused by water, cold, and sun may show symptoms similar to chronic hives.
For acute hives (short-term hives), it is important to differentiate it from skin conditions like erythema multiforme (red patches with a distinctive target-like appearance), toxic erythema (symmetrical, constant rash), sudden contact dermatitis (skin inflammation), pregnancy-related skin rash, and a toxic reaction from consuming spoiled fish.
What to expect with Contact Urticaria
Most patients with Chronic Urticaria (CU) find that their symptoms improve when they avoid certain triggers and take medications. The duration of the disease tends to be shorter in infants and children but can be more prolonged if it is associated with other allergic diseases or with other widespread symptoms, as seen in Intensive Care Unit (ICU) cases. If patients are repeatedly exposed to the same agents, the reactions in ICU cases can become increasingly severe.
Possible Complications When Diagnosed with Contact Urticaria
Intensive Care Unit (ICU) treatments can sometimes result in serious symptoms such as anaphylaxis, which is a severe and potentially life-threatening allergic reaction. Therefore, it’s crucial to diagnose and treat these patients correctly. Another potential complication is the risk of secondary bacterial infections due to repeated scratching, which can cause the skin to break down.
Potential Complications:
- Severe allergic reactions (anaphylaxis)
- Secondary bacterial infections from skin breakdown due to repeated scratching
Preventing Contact Urticaria
The best way to manage a disease is to avoid anything that causes it. For example, in the case of people who are allergic to natural rubber latex, it’s crucial to avoid this substance. They should instead use alternatives to latex gloves such as those made from bamboo viscose, neoprene, nitrile, or polyvinyl chloride (PVC).
There are steps you can take to prevent these allergies from happening in the first place. These include avoiding triggers, getting advice before starting a job that may involve exposure, and using personal protective equipment.
Other helpful steps are determining the right preventative measures at work, catching the disease early, and regular health checks.
For people with chronic hives, it’s important to have certain items on hand such as pens that can deliver epinephrine under the skin, antihistamines, and non-steroidal anti-inflammatory drugs (NSAIDs).
One last piece of advice is to resist the urge to scratch in order to prevent bacteria from getting into the skin. Scratching can increase your chances of developing a skin infection, which could lead to a skin abscess (a swollen area filled with pus) or cellulitis (a common skin infection).
