What is Chronic Urticaria (Chronic Hives)?
Chronic urticaria is a condition where there’s frequent appearance of hives, and/or swellings in the deeper layers of skin. These occur because of a type of cell, called a mast cell.
There are different types of this condition, classified based on how long it lasts and what causes it:
* Acute spontaneous urticaria: This type refers to hives and/or deep swellings that appear on their own and last for less than six weeks.
* Chronic spontaneous urticaria (CSU): This is when hives and/or deep swellings show up without any known cause and last for six weeks or longer. This is also known as “chronic urticaria” or “chronic idiopathic urticaria.”
* Chronic inducible urticaria (CIndU): This is when hives last for six weeks or longer and appear due to physical triggers, like touch or extreme pressure. This condition is also called “physical urticaria.”
What Causes Chronic Urticaria (Chronic Hives)?
The exact cause of Chronic Spontaneous Urticaria (CSU), a skin condition that causes hives and itching, is not completely understood yet. The main theory suggests it could be linked to a malfunction in the immune system where the body mistakenly produces antibodies that target compounds in your own blood, leading to a release of histamine that causes the skin to swell and turn red.
In studies, it’s been found that about 40% of people suffering from CSU positively respond to a skin test in which their own blood serum (part of the blood) is injected into their skin and triggers an urticarial reaction. Additionally, about one-third of patients with CSU revealed the presence of particular antibodies against specific compounds found within their blood serum.
People with CSU often have a higher rate of autoimmune diseases, where the immune system mistakenly attacks your own body. Hypothyroidism, a condition where your thyroid gland doesn’t make enough thyroid hormones, is notable among these. Other related conditions are rheumatoid arthritis, lupus, Sjogren’s syndrome, celiac disease, and type-1 diabetes.
Infections by various germs have also been linked to CSU, including different bacteria (like Helicobacter pylori and Staphylococci), viruses (like Hepatitis or Norovirus), and parasites (like Giardia lamblia). It’s not exactly known if these infections cause CSU, but they might trigger autoimmune reactions in the body that lead to the condition.
Food and additives, typically associated with immediate allergic reactions, seldom cause CSU.
Finally, it’s unclear if cancer and CSU are related, as studies looking into this have shown mixed results.
Risk Factors and Frequency for Chronic Urticaria (Chronic Hives)
Chronic Spontaneous Urticaria, also known as CSU, is found in about 0.23% to 1.8% of people both in the U.S. and around the world. It tends to affect women about twice as much as it affects men. CSU can occur in both children and adults, but it is most common in people who are 40 to 60 years old.
- CSU affects about 0.23% to 1.8% of the population in the U.S. and internationally.
- Women are twice as likely as men to have CSU.
- Both children and adults can have this condition, but it’s most common in those between 40 and 60 years of age.
Signs and Symptoms of Chronic Urticaria (Chronic Hives)
Urticaria, also known as hives, is a skin condition where itchy pink to red bumps, called papules, appear with a clear center. These papules can ooze and combine to create a larger patch on the skin. Each bump normally lasts less than a day and doesn’t leave any marks or bruises behind. It’s more common to find these bumps on parts of the body where there’s friction, such as the waist, armpits, and groin, but it can affect any area of the skin.
Scratching the bumps can cause further changes to the skin, like scrapes, sores, and bleeding crusts.
In some cases, up to 40% of the time, people with urticaria also experience angioedema. This condition results in swelling under the skin or mucous membranes, and it’s usually seen around the lips, eyes, genitals, and limbs. Instead of itchiness, patients usually feel discomfort or pain. Angioedema can take up to three days to fade and is the main symptom in 10% of chronic spontaneous urticaria cases.
Testing for Chronic Urticaria (Chronic Hives)
If you’re seeing a doctor for chronic spontaneous urticaria (CSU), they’ll start by asking detailed questions about your condition to understand possible triggers or factors that could be making it worse. They’ll want to know about how long you’ve been experiencing the hives, if you’ve noticed any swelling (angioedema), or if you’ve had other health-related symptoms. They’ll be interested in any history of allergies or autoimmune diseases, either in yourself or your family, your lifestyle habits, and your work environment.
The doctor may ask if you’ve been exposed to any physical elements that could cause the hives, such as sunlight or temperature changes, and whether the hives came about after taking any new medications or encountering any specific foods. They’ll also check for factors that could be making your condition worse.
If you can’t remember when the hives appeared, your doctor might outline one with a skin marking pen to see if it goes away within a day. This can help them better understand your condition. However, if you can’t recall and your doctor can’t detect any triggers from your history, it’s unlikely that they could identify an external cause for your CSU.
Your doctor may also order blood tests, including a complete blood count and checks for inflammation, to rule out other conditions. If your blood shows an unusually high number of a certain type of white blood cell (eosinophilia), this could suggest an allergy or a parasitic infection. Elevated inflammation indicators could signal an associated systemic disease. Unless there’s a reason to suspect a specific condition based on your history, additional investigations are unlikely to reveal new information.
Allergy skin tests are generally not useful for CSU since this condition is rarely caused by a type I allergy. The use of a patient’s own serum in skin testing to look for certain antibodies is an ongoing area of research.
Several methods have been developed to measure the severity of your condition (like the urticaria activity score), how well it’s being managed (such as the urticaria control test), and how much it’s affecting your quality of life (with tools like the chronic urticaria quality of life index). These assessments can offer useful insights to help your doctor make decisions about your treatment and monitor your progress.
Treatment Options for Chronic Urticaria (Chronic Hives)
The main goals of managing CSU (Chronic Spontaneous Urticaria) are to avoid triggers that worsen the condition and to control symptoms. Medications used for treatment aim to prevent immune cells known as mast cells from releasing inflammatory substances or to mitigate the effects of these substances after they’re released.
First choice for medication treatment are second-generation H1-antihistamines, like cetirizine, loratadine, and fexofenadine. They are taken regularly and the dose can be increased up to four times the typical amount if symptoms remain after 2 to 4 weeks. First-generation antihistamines are not recommended due to side effects on the nervous system and their anticholinergic properties, which can cause dry mouth and blurred vision among other side effects.
A key difference in treating CSU and inducible urticaria is that for the latter, treatment can be used as needed if the patient knows their trigger and can prepare by taking an antihistamine about two hours before expected exposure.
An effective second-line therapy for CSU resistant to antihistamines is omalizumab. This medication is a monoclonal antibody that binds to a type of immune protein called IgE. It’s given as a subcutaneous injection, typically 300 mg every 4 weeks.
Ciclosporin is recommended as a third option for CSU that doesn’t respond to both antihistamines and omalizumab. Since it’s not officially approved for CSU, its dose and duration should be kept minimal to avoid side effects like kidney damage and high blood pressure.
For sudden flare-ups of CSU, brief instances of steroid treatment may help to reduce the severity and duration of symptoms. Steroids applied directly to the skin, however, don’t play a role in CSU management.
Some other treatment options, including leukotriene antagonists, dapsone, methotrexate, sulfasalazine, plasmapheresis, phototherapy, and intravenous immunoglobulin, have been investigated. However, current evidence supporting them is limited and of low quality.
What else can Chronic Urticaria (Chronic Hives) be?
Urticarial vasculitis is a type of blood vessel inflammation where the person develops skin welts (hives) that last more than 24 hours. These hives are typically painful, not itchy, and once they settle, they may leave behind a bruised or pigmented area.
Papular urticaria is a reaction to insect bites. It features clusters of itchy bumps, sometimes with a central spot, that can last from several days up to a few weeks.
Mastocytosis includes diseases caused by an excess of mast cells (a type of immune cell) in the skin and internal organs. A telltale sign of this condition known as Darier sign, is when a welt appears after lightly rubbing the skin.
Auto-inflammatory syndromes such as cryopyrin-associated periodic syndromes (CAPS) and Schnitzler syndrome may cause hive-like rashes, fever, joint pain, and other symptoms affecting the body.
If a patient has swelling (angioedema) without signs of a rash, it could be due to a deficiency in the C1-esterase inhibitor. This condition may be hereditary or acquired. Bullous pemphigoid is a disease of the immune system commonly found in older adults. It starts with itching and hives-like patches and advances to form large, fluid-filled blisters. Anaphylaxis is a severe allergic reaction that can be life-threatening. It often starts quickly with skin symptoms like hives and swelling.
What to expect with Chronic Urticaria (Chronic Hives)
Generally, CSU tends to gradually improve on its own, often lasting between 3 to 5 years on average. There’s a high possibility of the condition going away within the first year, which reportedly occurs in about 80% of cases.
However, a small number (around 14%) of patients might experience the disease for more than 5 years. There are certain factors associated with a longer disease duration such as thyroid autoimmunity and the concurrent presence of angioedema, a condition characterized by rapid and severe swelling.
Possible Complications When Diagnosed with Chronic Urticaria (Chronic Hives)
Chronic Spontaneous Urticaria (CSU) can cause itching that severely impacts the patient’s quality of life. This can interfere with daily activities and sleep. CSU can also have a negative effect on a patient’s overall health status.
Preventing Chronic Urticaria (Chronic Hives)
It’s important for patients to understand their treatment goals. Regularly taking H1-antihistamines (a type of allergy medication) can control symptoms better than taking them only when needed. It’s also crucial to understand and avoid things that can make the skin conditions urticaria and pruritus (hives and itchiness) worse. These include:
- Medications: Certain drugs, specifically non-steroidal anti-inflammatory drugs (otherwise known as NSAIDs) and aspirin, can cause non-allergic reactions in some patients. These reactions can worsen symptoms, so it’s best to avoid these drugs if possible.
- Sickness: If a patient is experiencing a bacterial or viral infection, their hives may worsen.
- Environmental factors: Things like tight clothing and heat (like from hot showers) can often make symptoms worse.