Hives (Urticaria) Overview

Hives, known clinically as urticaria, is an inflammatory skin condition that causes bumps, or wheals, to form on the skin. It sometimes occurs alongside angioedema, which is a broader area of swelling. This condition arises due to the activity of skin mast cells and the subsequent release of histamine, a compound associated with immune response. About 20% of the population experiences urticaria at some point in their lifetime.

Hives symptoms typically resolve on their own within a week. However, some people develop chronic urticaria, in which flares recur regularly after six weeks of onset. Treatment for this condition depends on the individual case, focusing on symptom management and steering clear of any triggers. Though hives can significantly impact your quality of life, there are a number of successful therapies for this condition.  

Types of Hives

Clinically, hives cases are primarily classified based on two factors: the cause of the symptoms and the amount of time that they persist. There are three classifications: acute, chronic spontaneous, and inducible. The classification influences the treatment approaches used for the condition.

Acute Urticaria

Acute urticaria refers to cases that resolve on their own without medical treatment within six weeks of initial onset. About two-thirds of all hives cases are acute. The causes of this type are usually unknown (termed “idiopathic”), though the symptoms can also arise due to allergic reactions, medications, or an underlying infection.    

Chronic Spontaneous Urticaria

If hives symptoms persist longer than six weeks, the condition is considered chronic. Most of these cases are chronic spontaneous urticaria, in which the issue is idiopathic, and no specific trigger or cause can be identified. In the United States, about 1% of the population is estimated to have this form.

Inducible Urticaria

Also known as physical urticaria, this form of hives arises due to an identified trigger or external factor. Common causes of this type include:

• Heat
• Cold 
• Pressure on the skin
• Exercise
• Water or being wet
• Wearing or touching latex
• Exposure to sunlight
• Allergens, such as pet dander

Inducible urticaria can impact people of all ages and represents an estimated 20 to 30% of chronic hives cases.

Hives Symptoms

Hives can present with a variety of symptoms, including wheals, angioedema, itching, and systemic symptoms such as headache, nausea, and more.

Wheals

The primary feature of hives is the development of round, oval, or irregularly shaped welts on the skin, known as wheals. They are generally reddish or darker in color, turning temporarily white when you press on them. Setting on rapidly—within minutes to hours—they range in size from less than one to a couple of centimeters. Individual wheals resolve on their own within 24 hours and leave no mark.

Wheals can arise anywhere on the body, though they are typically more prevalent in areas that are under pressure from clothing or on skin that regularly comes into contact with other skin. While hives do not cause pain, eruptions of the condition cause severe itchiness, termed clinically as pruritis. This is typically more severe at night.

Angioedema

Angioedema—patches of swelling under the skin—occurs alongside wheals in about 40% of hives cases. In some cases, this issue can even arise independently. This swelling most often affects the face, lips, limbs, genitals, and spaces around the eyes. As with wheals, angioedema arises quickly and can cause sensitivity, tingling, and numbness. 

Itching

Itchiness is a very common symptom of hives, occurring with or without the presence of wheals. In some cases, itching is the only symptom someone with hives experiences. Itching most commonly occurs with chronic hives, but can happen with any type. Itchiness can sometimes be exasperated by physical triggers such as extreme hot or cold temperatures.

Systemic Symptoms

Though the impact of hives is primarily seen in the skin, a small subset of people with chronic spontaneous urticaria experiences an additional set of body system symptoms. Typically accompanying more severe cases, these include headache, swelling in the joints, fatigue, wheezing or breathing difficulties, flushed skin, nausea, vomiting, abdominal pain, and heart palpitations.

Quality of Life

Because hives can affect your appearance and since it causes itchiness, the condition can significantly impact your quality of life. Since the symptoms are often worse at night, you may experience difficulty getting to or staying asleep. Furthermore, these symptoms can impact daily life and performance at work or school.

What Causes Hives?

At its core, hives is an inflammatory reaction of the skin. The symptoms arise due to the activation of mast cells, which are skin cells that spur your body’s immune response to infection. Similar to allergic reactions (and sometimes resulting from them), these cells trigger the release of histamines and antibodies, which are at the root of itching, swelling, and symptoms.

Several different factors can cause this skin reaction. Acute cases can be set off by allergic reactions to certain foods and drinks, direct contact with some plants (as when you touch stinging nettles), as well as some medications, such as non-steroidal anti-inflammatory drugs (NSAIDs). As noted above, cases of inducible urticaria are triggered by exposure to physical stimuli, such as latex, heat, cold, wetness, and others. However, researchers aren’t sure as to the causes of chronic spontaneous urticaria.  

Risk Factors

While all people can be affected by hives, certain health factors increase your risk of developing this condition. These include:

• Age: Acute hives are most prevalent in children and infants 5 years old and under. 
• Sex: Among adults, those assigned female at birth are more likely to develop hives.
• History of allergy: Those who have allergies or have had hives before are more likely to develop the condition.
• Family history: Genetics seems to play a role as having close relatives with the condition increases your chances of having it, too.
• Autoimmune diseases: Having rheumatoid arthritis or autoimmune thyroid disease may increase your risk of hives. 
• Stress: Some people develop hives as part of a physical response to stressful situations, making high stress a risk factor.

How Are Hives Diagnosed?

Primarily, the diagnosis of hives involves clinical evaluation of symptoms and assessment of medical history. Dermatologists (doctors who specialize in conditions of the skin, hair, and nails) will ask about the severity of your symptoms, any potential triggers, family history of hives, allergies, and medications you’re taking. In addition, diagnosis may include:

• Physical evaluation: The healthcare provider will visually assess wheals or angioedema and assess your overall health by measuring heart rate, body temperature, blood pressure, and breathing.
• Symptom assessment: Alongside visual assessment, the dermatologist may also test dermographism, a primary sign of hives. This is when wheals form within minutes after pressure is applied to the skin (typically by the blunt side of a pen or tongue depressor). Since wheals typically disappear within 24 hours, individual bumps may be circled with a pen, and you may be asked to come back to see if there are any changes.
• Skin prick test: Because allergic reactions can cause hives to develop, you may be tested for allergy using a skin prick test. A small amount of potential allergen is injected into the skin, and the extent of any swelling reaction (a sign of allergy) is assessed 15 minutes afterward.
• Blood tests: Complete blood count (CBC), erythrocyte sedimentation rate (ESR), and allergen-specific immunoglobin (IgE) are among blood tests used to screen for signs of inflammation and identify causes of hives.
• Challenge testing: To test for inducible urticaria, healthcare providers will assess skin responses to certain stimuli, including exposure to cold, water immersion, heat, and pressure on the skin.

Treatment

A majority of hives cases are acute and resolve on their own without the need for additional treatment. However, especially in chronic cases, additional and more sustained therapy is needed. The goal of this work is to avoid triggering attacks and to ease itchiness and discomfort. Several strategies may be employed.

Trigger Avoidance and Lifestyle

If the hives are identified as arising due to exposure to specific triggers, such as heat, cold, or direct sun, then strategies can be developed to avoid them. In addition, modifying certain lifestyle factors can help. You may be advised to avoid alcohol (which can make symptoms worse) or stop using NSAIDs or other medications.

Antihistamine Medications

Antihistamines are a class of anti-allergy medications that serve to ease the inflammatory process at the root of hives symptoms. In acute cases, you may be advised to take an over-the-counter antihistamine and see if that helps. In chronic or more severe cases, prescribed antihistamines include:

• Benadryl (diphenhydramine)
• Vistaril (hydroxyzine)
• ChlorTrimeton (chlorpheniramine)
• Claritin (loratadine) 
• Zyrtec (ceterizine) 
• Allegra (fexofenadine)

Corticosteroids

If antihistamines aren’t yielding results, your healthcare provider may prescribe another class of medication, a corticosteroid. Common corticosteroids include drugs like prednisone and hydrocortisone. This therapy is often indicated alongside other drugs, such as antihistamines.

Antacids

Antacids, which are also known as acid reducers, are typically used for acid reflux or heartburn, but they can also be used to help with managing hives. This is because the histamines that trigger hives also stimulate cells in the stomach, producing excess stomach acid. Antacids are only prescribed for hives treatment in combination with antihistamines. Common antacids include Pepcid (famotidine) or Tagamet (cimetidine).

Other Medications

A couple of newer therapies have emerged for hives. If antihistamines or other approaches haven’t succeeded, an allergist or dermatologist may prescribe the biologic Xolair (omalizumab). This type of drug is a monoclonal antibody and is known to have an anti-inflammatory effect that can ease symptoms.  

In addition, leukotriene-receptor antagonists, such as Singulair (montelukast) and Accolate (zafirlukast), may have a similar effect.

How to Prevent Hives

Depending on the case, there may be ways to prevent the onset of hives and limit the recurrence of symptoms. Prevention strategies include:

• Seeking out medical care: Consultation with an allergist or dermatologist to confirm your diagnosis and begin management can go a long way in easing the burden of the condition. 
• Tracking flares and triggers: Keep a record of when you are getting symptoms, as well as what may be setting them off. If you know of dietary or other triggers, try to avoid them as well as you can. Steer clear of alcohol and potential problem medications, such as NSAIDs.
• Mental health: Since stress can be a factor in the development of hives, developing means of relaxation may help. Meditation, yoga, exercise, getting good quality sleep, or even taking walks may help. 

Comorbid Conditions

Having hives, especially in chronic form, is associated with a higher risk of developing a number of diseases. These comorbid conditions include:

• Depression and anxiety: Among the most commonly reported conditions associated with hives are depression and anxiety. The quality of life disruption associated with chronic cases, including impacts on self-image, can have a major impact on mental health.
• Rheumatoid arthritis: Rheumatoid arthritis occurs when the immune system mistakenly attacks and damages joints, causing painful swelling and inflammation. This increased immune activity may also lead to hives development. 
• Other autoimmune conditions: Alongside rheumatoid arthritis, the risk of other autoimmune conditions, such as thyroiditis, a disease of the thyroid, and vitiligo, the formation of patches of pigment-less skin, may increase in chronic hives cases. 
• Atopic dermatitis: Commonly known as eczema, this is excessive dryness, flakiness, and brittleness of the skin. This condition shares with chronic hives an underlying hyperactivity of immune function.
• Asthma: Characterized by attacks of severe breathing difficulties and wheezing, asthma rates are higher among those with chronic urticaria. Both conditions are linked to elevated levels of IgE antibodies as part of an inflammatory response.
• Osteoporosis: Studies have also linked hives with osteoporosis, a condition that causes bones to weaken and become brittle. Similar allergic and immune processes have been observed in both cases. 
• Diabetes mellitus: Causing an inability to digest sugars, diabetes mellitus may also be a comorbid condition. While the exact links with hives are unknown, both conditions involve higher activity of mast cells.  

Living With Hives

While hives can be very uncomfortable, they rarely are dangerous. Only in cases of severe allergic shock do they imply anything life-threatening. Acute cases are self-limiting and go away on their own without the need for treatment. 

That said, chronic hives can significantly impact mental health and well-being. Since it causes issues like sleep problems, fatigue, and difficulty concentrating, those living with it are at a higher risk of stigmatization, sadness, anxiety, and social isolation.

That said, medical management is highly successful in managing the burden of the condition. If you experience persistent symptoms, be sure to seek out medical care from a dermatologist or allergist. Carefully follow your treatment plan, as well as make dedicated lifestyle changes. Over time, you’ll be better able to manage symptoms and prevent them.