A sudden outbreak of swollen and reddish bumps is the primary symptom of urticaria, also known as hives.
Urticaria is not a single disease but rather a reaction pattern, and the body’s mast cells are at the centre of this reaction.
These cells, found in clusters in connective tissues, release histamine in response to allergic and inflammatory reactions. The excess histamine causes the trademark pale red patches in hives.
Hives occur due to high levels of histamine in the skin, causing plasma to leak out of small blood vessels in the skin. What triggers the increase in histamine levels, however, remains unclear.
Different triggers can cause the sudden spike in histamine levels.
Foods like nuts, fish, eggs, milk, and chocolate may contribute to the development of acute urticaria. Note that consuming fresh foods, rather than cooked food, pose a greater risk for hives. Some additives and preservatives can also set-off a reaction.
While food is a common cause of hives, other factors can trigger excessive histamine release such as:
Rare and chronic varieties of urticaria are also autoimmune diseases, and one’s genes play a critical role in the development of the disorder.
It is unknown why autoimmune urticaria develops, but it is sometimes believed to develop alongside other autoimmune conditions like:
In a later section, we will look at the different types of urticaria as well as the most common culprits that cause the condition.
The number of episodes is at the greatest in patients aged between 20 to 30 years old.
Note, however, that children are also at risk. A study involving 4,076 children aged four to 13 years old saw the prevalence of lifetime, acute, and chronic urticaria at 22.5%, 13.9%, and 1.8% respectively.
Interestingly, the study concluded that living in a new residence and belonging to a high-income family increase the risk of chronic continuous urticaria.
Urticaria’s most visible symptom is reddish raised areas of the skin akin to nettle stings.
The rashes, also called wheals, are often round in shape and span one to two centimetres across, about the size of a pencil eraser. However, the wheals may join together and form plaques, which can become the same size as a dinner plate!
The wheals can appear about anywhere on the body, including your:
While harmless in general, they are itchy and may also burn or sting.
Individual wheals can often last 24 hours before fading away without a trace, only to be replaced by new wheals. The course of hives continues for much longer than any individual rash, about 6 months or so depending on the type.
Hives are itchy and annoying. Not to mention the rashes can look alarming when they form together. But acute and chronic urticaria is not life-threatening in general.
On the other hand, you may experience other symptoms aside from rashes and itchiness, and you want to exercise extra caution in such cases. If your hives are severe and are accompanied by:
Get medical help immediately.
Hives can be extremely severe and may appear in the tongue or throat, blocking the passage of air and causing the signs above. The symptoms may also be an indication of anaphylaxis, a more serious and life-threatening reaction.
The appearance or description of hives is often enough for the doctor to make a diagnosis.
But as mentioned earlier, singling out the cause can prove problematic.
Certain cases may have an obvious trigger. A person eats something known for causing allergic reactions, like seafood or nuts, and then experiences an outbreak. Most of the time, however, identifying the trigger calls for detective work and cooperation between the patient and doctor.
Your doctor will have to ask you a series of questions to identify potential causes, though a single episode of hives won’t require comprehensive tests.
If a food allergy is a possibility, your doctor may instruct you to keep track of what you eat in a food diary.
Keeping an eye on what you eat can help you and your physician identify ingredients or substances that can trigger urticaria. From here, you can remove certain foods from your diet to see if your condition improves. The foods may be reintroduced to establish a verdict on whether or not they cause or aggravate the condition.
The severity of the symptoms and hives itself often fluctuates. So keeping a food diary to identify triggers isn’t 100% accurate.
Chronic urticaria, on the other hand, requires an allergist for evaluation.
The allergist will ask questions about:
Your doctor may also take blood or urine samples and send them to the laboratory to look for illnesses or infections that trigger hives.
You may also have to undergo a biopsy, a process which removes a small portion of your skin for examination under a microscope. Doctors usually recommend this procedure if they suspect that vasculitis, an inflammation of the blood vessels, is causing your hives.
Autoimmune urticaria (AIU) can prove especially difficult to diagnose.
Recently, however, researchers from the University of Debrecen found several parameters can improve the accuracy in diagnosing AIU when combined with autologous serum skin test (ASST). The parameters are:
All of which require simple tests to establish.
Urticaria can be associated or even mistaken for other conditions with identical symptoms, such as angioedema. But the latter is a different beast from hives.
Below, we discuss the different types of urticaria in specific.
The condition becomes evident within a few minutes after exposure to an allergen or trigger. The outbreak can last for more than a month but completely resolves within six weeks.
Food is one of the most common triggers of short-term hives.
While our mast cells are responsible for histamine production, the latter may also find its way into our bodies through food. Some foods are naturally high in histamine, while others increase their histamine content through fermentation.
Here are some examples of foods high in histamine:
An array of drugs can also trigger the condition, including NSAIDs like aspirin, ibuprofen, and naproxen. Antibiotics, antidepressants, and vaccines may also set it off. Certain active ingredients can also inhibit the degradation of histamine into the small intestines, causing hives. The list includes:
The symptoms and appearance of urticaria are similar across different types, acute or otherwise. But the severity and duration can vary as we’ll see.
Like the acute version, red, itchy, and raised patches of skin characterize this condition.
The only exception, however, is that chronic urticaria lasts longer than six weeks. The condition can last for months or even years. But the severity of chronic hives is a bigger cause for concern.
Patients with the condition, along with their families, have to endure heavy emotional and economic burden. The patient’s social functioning also suffers as a result of sudden and repeated bouts of burning and itchy wheals, severely reducing their quality of life.
Among many things, getting enough quality sleep is a challenge.
Worse, according to researchers from Warsaw’s Military Institute of Medicine, sleep disruption in patients with chronic urticaria also led to a higher incidence of sleep-related breathing disorders.
Long-term hives is also known as chronic idiopathic urticaria (CIU) and chronic spontaneous urticaria (CSU), meaning the cause of the outbreak is undetermined.
Note, too, that chronic urticaria in 50% of adults and children patients is an autoimmune response. As with most autoimmune diseases, the anecdotal proof shows it’s reversible, but doctors have no direct cure for this variety of hives.
With the cause unknown and a cure yet to be found, patients with chronic urticaria often take a long-winded journey, jumping from one specialist to another to find the most effective management solution.
Chronic urticaria can also be connected to other chronic illnesses like:
We’ve looked at classifications of urticaria based on their duration and severity.
But another group of hives is triggered by a physical stimulus, like exposure to sunlight or sweating. This variety of hives are known as inducible or physical urticaria. The episode of urticaria following a trigger can be acute or chronic.
Dermographism literally translates to “skin writing.”
Firm stroking of the skin in normal people (ex: with fingernails or a car key) triggers the ‘triple response of Lewis’. A red line appears at the stroked portion of the skin, followed by a flare, and mild swelling.
For about two to five percent of the population, however, the response is so pronounced one can read and distinguish the marks. These people have dermographism urticaria.
The wheals don’t carry other symptoms in most cases. But a minority of people may experience wheals and itchiness after stroking their skin. A condition called symptomatic dermographism urticaria (SDU).
If you suspect you have this condition, you can rest easy knowing that dermographism urticaria is benign.
Solar urticaria is a rare condition first described in 1904.
A person with solar urticaria develops wheals and severe itching of the skin after brief exposure to natural or even artificial light. The onset of the symptoms is often sudden and dramatic. And with little information available about its duration, solar urticaria is hard to manage for most patients.
Treatment can be frustrating, too.
Medications like H1-receptor blockers and phototherapy are among the treatment options. But the success of these approaches often fluctuate.
The results of antihistamine therapy, on the other hand, depend on the severity of the solar urticaria.
A patient who takes 10 to 15 minutes to develop hives after exposure to light is likely to find antihistamines helpful. But someone who starts itching within seconds of exposure needs a different treatment.
Whatever mode of the treatment your doctor prescribes, minimising exposure to the sun and other light sources is priority number one for patients with solar hives. Lifestyle changes may involve wearing protective clothing, generous and regular applications of the right sunscreen, or even changing jobs.
Sweat is the physical stimulus that triggers cholinergic urticaria.
The hives appear within minutes after the onset of sweating, and they may last for up to 80 minutes. This condition causes discomfort, so much so that patients have to stop or change what they’re doing to prevent the attack from escalating.
Developing cholinergic urticaria can be especially disheartening for fitness enthusiasts as exercise is the most common trigger for the condition. However, any activity that causes sweating may trigger an urticarial attack. The list includes:
Antihistamine therapy is a common recourse for cholinergic urticaria patients. But some forms of the condition are resistant to traditional treatment options. In other cases, an outbreak of hives can be stopped by rapid cooling and using ultraviolet light.
As with other types of hives, the patient must make lifestyle changes to cope with the disorder. Alcohol, hot foods and beverages, and spicy food are off the menu for a person with cholinergic urticaria.
Patients will also have to avoid activities that induce sweat, like working out or holidaying in warm regions, to deter outbreaks.
Pressure urticaria, where hives occur after exposure to pressure, is another rare variety of physical urticaria. The onset of wheals and itching may happen within minutes or within four to six hours, as is the case in delayed pressure urticaria (DPU).
Patients may experience other symptoms along with the rashes and itching such as burning and pain, and they may last up to three days. Exposing any part of the body to pressure may trigger hives. But the hands, feet, buttocks, and legs are most prone to outbreaks.
Pharmacologic treatment options for pressure urticaria isn’t always effective.
Second-generation antihistamines can reduce the severity of chronic idiopathic hives that follow exposure to pressure. But ultimately, they can’t control the symptoms. NSAIDs, on the other hand, deliver mixed results and can even worsen an episode of hives.
As for the patient, limiting pressure stimuli is a critical step in managing the disorder.
Standing, walking, sitting, and leaning on hard surfaces may trigger the itchy wheals, and avoiding these activities may be necessary. One may also need to replace tight fitting clothes with airier ones, or broaden and cushion the straps to disperse pressure.
After looking at the different types of hives and their known triggers, maybe you’re now itching to learn about the treatment and management options available. You will notice that, in both acute and chronic urticaria, active participation by the patient in managing the condition is of utmost importance.
Acute urticaria clears up within four to six weeks. So the primary goal of the treatment is to manage and control the severity of the symptoms during the course of an outbreak.
Primary care providers have enough know-how to manage most cases of acute hives. If your doctor identifies a trigger and avoidance of the suspected cause resolves the problem, then the patient need not consult a specialist.
However, your doctor may suspect an allergic reaction but can’t zero-in on the exact trigger. In such cases, speaking to an allergist is recommended. The same is true if avoiding a trigger doesn’t fix the problem or if the patient is not responding well to antihistamines.
The latter may warrant in-patient therapy, especially if the hives are severe and the patient shows signs of anaphylactic shock, including:
Most cases of acute hives are benign, and a combination of pharmacological and non-pharmacological treatment methods can effectively relieve the symptoms. Let’s take a look at the options available.
Diphenhydramine, clemastine, and brompheniramine are among the first-generation antihistamines. They reduce the wheals and intense itching, but their efficacy comes at a price.
The older antihistamines can leave a number of side effects in their wake, including drowsiness and cognitive impairment. These adverse effects can also continue until the next day depending on the patient and the dose.
Medical guidelines advise against using these sedating drugs unless a special indication compels a doctor to do otherwise, especially since second-generation antihistamines are relatively non-sedating and have excellent safety track records.
If you must turn to first-generation antihistamines, however, take them at bedtime. This way, they won’t interfere with your activities during daytime and you fall asleep much faster.
Taking medications at night is not an option for everyone, of course.
So if you need your dose during the day, you should get a cab instead of driving to work. You also shouldn’t operate heavy machinery nor carry out any activity where inattention can put your safety and others at risk.
Cetirizine, loratadine, and fexofenadine belong to the second generation of antihistamines. Specialists and care providers prefer the newer drugs as they are safer and have very few reported side effects.
Of course, the safeness of just about every drug is relative. Different factors are at play during treatment such as possible allergies due to a certain antihistamine as well as other medications you are taking.
Specialists may also prescribe drugs that reduce the secretion of gastric acid (H2 blockers) along with second-generation antihistamines. The combination has been shown to better treat the symptoms of acute urticaria than antihistamine or an H2 blocker alone.
For people with acute or short-term urticaria, knowing that the condition will only last up to six weeks is a relief. Chronic urticaria patients, however, don’t have that luxury.
Chronic urticaria can persist for years, and the onset of burning, itching wheals can be quite sudden. Both the trigger for the hives and the cure can be elusive, often requiring a series of tests to get closer to answers. In many cases, a patient is never cured of urticaria as is the case in autoimmune hives.
And to add to the problem:
"A high proportion of people who do get a diagnosis have to wait as long as 18 months or more to get a referral to a specialist," noted Dr. Roger Henderson in his column for The Spectator.
Proper and consistent management of the symptoms for a long time is a must if a patient is to remain functional. And even so, people with the condition are likely to suffer a significant reduction in their quality of life.
The disruption brought about by chronic urticaria on the daily activities, social interactions, work, and quality of rest is similar to what heart disease patients experience.
Moreover, the wide-ranging effects of the condition can erode one’s emotional state, so much so that a 2009 study advises care providers to talk to their patients about the emotional impact of chronic urticaria.
As in acute urticaria, antihistamines play a crucial role in keeping chronic hives under control. Second-generation and low-sedation antihistamines are the go-to prescriptions. But know that daily intake improves quality of life in patients more than taking antihistamines only when needed.
Initially, your doctor may prescribe a long-lasting antihistamine once a day, usually in the morning. But if this isn’t enough, doubling the dose is not only necessary, but it is also often the safest therapeutic approach when patients don’t get the relief they need with the usual dosage.
The European Academy of Allergy and Clinical Immunology suggests increasing the dosage of second-generation antihistamines up to four times should the situation call for it.
Chronic urticaria patients may not notice or feel the severe itching during the daytime when the antihistamine is doing its work while activities keep them busy.
But itching can become troublesome at night, especially since the effects of the long-acting antihistamine are wearing off and there are fewer distractions. To fix the problem, your doctor may prescribe a first-generation or sedative antihistamine, which works double-time by providing symptomatic relief while helping patients go to sleep.
Antihistamines aren’t the only medications available to help in managing urticaria. Your physician may recommend some of the following drugs depending on their findings:
Remember that all medication is prescribed on a case by case basis, and that if you have any questions about a certain medication you should always consult your doctor or specialist first.
No matter what form of urticaria a person may live with, there are some universal methods for managing the symptoms alongside your prescribed medication.
If food allergies are suspected, maintaining a food and symptom diary for two to four weeks can help in establishing a conclusion. The patient will need to write down any food they consume about six to eight hours before the onset of hives.
Some cases saw patients eat a certain food (ex: peanuts) and not result in an outbreak. But hives recur when eating the same food before or after performing an activity like working out. So be sure to write down the activities you engage in, too, for good measure.
Activity monitoring is especially important if your doctor or specialist suspects physical urticaria. As we’ve discussed, everyday stuff can trigger a flare-up in many people - from walking outside, taking a dip in the pool, to simply sitting.
Keeping a diary will help your doctor or specialist match your symptoms with their possible triggers.
Prevention is better than cure. The Journal of the European Academy of Dermatology and Venereology recommends avoiding known triggers as an essential step in managing the symptoms of chronic hives.
Doing so could mean giving up foods or activities we enjoy. But complete avoidance is critical, so the condition doesn’t get out of control.
Once you have worked out what your triggers are, either via keeping a diary or through another method, knowing what to avoid will be much easier.
If you or your doctor think that a certain medication may be causing your symptoms, contact the doctor who prescribed it to you. They will know if there are alternatives available.
Give your skin some TLC. The drier it is, the itchier it gets and the greater the temptation to scratch. Scratching the wheals is the last thing you want to do as it can worsen the condition.
Instead, you should soothe and moisturise your skin by applying a topical cream, or a gentle, unscented moisturiser.
Applying these creams straight after a bath or shower will help seal moisture into the skin and prevent it from escaping so easily.
Aloe vera gel can also be used due to its anti-inflammatory and antimicrobial properties. It helps to reduce redness, itching and swelling when applied to the skin. Because of these properties, it is also used to help soothe sunburn and irritated skin from waxing or laser hair removal.
When buying an aloe vera gel, look for one with as little ingredients as possible and as close to 100% aloe vera gel as possible.
Make sure to hydrate your skin from the inside out by drinking lots of water.
If you’re having a flare-up of hives, try using a cold compress to help reduce the inflammation and itching.
Using a cold compress can help shrink the blood vessels and restrict blood flow to the area. This should also stop more histamine being released, in turn calming the flare up quicker.
Try wrapping ice cubes or a frozen bag of peas in a tea towel and apply to the flare-up for around 5 to 10 minutes.
Many people are deficient in vitamin D, especially during the winter months. Talk to your doctor about vitamin D supplements.
Getting your daily dose of vitamin D is easier in the summer months when even 10 minutes of sun exposure can be enough. However, if your symptoms are related to the sun, supplementing is of extra importance.
The conclusion of a two-year study published in the Annals of Allergy, Asthma & Immunology saw daily intake of vitamin D3 (on top of regular medications) reduced the symptoms by 33 percent within the first week.
Oatmeal is anti-irritating, anti-inflammatory and soothing due to its naturally high salicylic acid content. It’s well known to help naturally soothe your skin and is commonly suggested to help manage eczema as well.
Try soaking in an oatmeal bath for 20 minutes to help reduce your flare up. Add 1 or 2 cups of ground oatmeal directly to a lukewarm bath, or tie the oatmeal up in a cheesecloth or a pair of tights and put it under the tap while the taps are running.
Make sure that the water is only lukewarm, and not too hot or cold as any extreme temperature could make your flare up worse.
Avoiding stress is easier said than done, as for some it can play a part in day to day life.
Where possible, avoid situations that you know will be stressful. This may not always be possible, so consider adopting techniques which promote calm and relaxation like meditation or deep breathing. These activities can help keep both stress and hives at bay.