What Causes Hives?
Hives affect approximately 20% of people at some point during their lives and can be triggered by different substances or situations. Hives can appear anywhere on the body as small spots, blotches, or large and connected bumps. The welts that result from hives arise when certain cells release histamines, chemicals the body produces to defend itself against outside intruders, and other chemicals into the bloodstream. In some people, histamines can cause swelling, itching, and several hives-related symptoms. In terms of allergens, there are different potential hives causes, including pollen, medications, foods, animal dander, and insect bites. Hives can also be caused by stress, tight clothing, exercise, illnesses, infections, or more.
It’s also possible for hives to develop due to excessive exposure to hot or cold temperatures or irritation due to excessive sweating. Hives are not contagious, meaning it's impossible to catch hives from another person or transmit them to another person. However, hives may occur along with contagious infections or health conditions.
Symptoms Of Hives
Hive symptoms may include varying features, though most commonly include the presence of raised, red or skin-colored itchy bumps and blanching, which refers to the center of a red hive turning white when the hive is pressed or pushed against. The most noticeable symptom associated with hives is skin welts. Welts can be red or skin-colored and small and round, ring-shaped, or large and a random shape. Hives are often itchy and tend to develop in batches on the affected body area.
The hives can grow larger, change shape, and spread to other body areas. Hives can appear, disappear, and reappear during the outbreak. Each hive can last anywhere from half an hour to a day. Sometimes, the hives can change shape or combine to create a larger, raised area of skin. Hives can occur nearly anywhere on the body, but if you develop a hive outbreak around your throat or tongue or have trouble breathing with hives, contact 911 or seek medical attention immediately.
Who Is At Risk Of Developing Hives?
Individuals with allergies are more likely to develop hives than those without allergies. People may also be at risk of developing hives if they are on medications or unknowingly exposed to things they may be allergic to, such as certain foods or pollen. People already ill with an infection or health condition may be more vulnerable to developing an urticarial rash. When hives result from an allergy or sensitivity reaction, it can significantly affect the face (hives on face) by causing swelling in the lips, for example. Should the hives on lips become more widespread, they can affect the mouth, throat, and airways, making breathing difficult. This is considered an emergency and requires immediate medical care, as the person is at risk of developing anaphylaxis, which is a life-threatening condition.
Types Of Hives
There are multiple types of degrees in severity associated with conditions with hives, including allergic reactions, anaphylaxis, chronic hives, dermatographism, temperature-induced hives, and infection-induced hives.
Allergic Reactions
The most common cause of hives is an allergic reaction, which can be caused by any allergen a person may be sensitive to, including foods (like nuts, milk, and eggs), pet dander, pollen, dust mites, insect bites or stings, and medications (like antibiotics, cancer drugs, and ibuprofen). Mild hives resulting from allergies are often treated with long- or short-term allergy medications and strict avoidance of the trigger or triggers.
Anaphylaxis
Anaphylaxis is a severe and life-threatening allergic reaction. With this condition, hives are often accompanied by breathing difficulties, nausea, vomiting, severe swelling, and dizziness. If you suspect anaphylaxis, you should call 911 or seek medical attention immediately.
Chronic Hives
Chronic hives comprise ongoing cases of hives that may not have identifiable chronic hives causes. Also known as chronic urticaria, this condition is characterized by recurring hives, lasting anywhere from 6 weeks and several months or years. Chronic hives can be a symptom of an underlying health problem, such as celiac disease, lupus, type 1 diabetes, rheumatoid arthritis, thyroid disease, or other health conditions.
Dermatographism
Dermatographism is a form of acute hives, generally considered mild, and can be caused by excessive scratching or continuous pressure on the skin. Dermatographism usually clears up on its own in a short period, typically without treatment by a medical professional.
Temperature-Induced Hives
In some cases, temperature changes can induce hives. Cold-induced hives can occur due to exposure to cold water or air, while body heat from physical activity or another cause can cause exercise-induced hives or heat hives. Solar hives can result from exposure to sunlight or using tanning beds.
Infection-Induced Hives
Viral and bacterial infections can cause hives. Common bacterial infections that cause hives include urinary tract infections and strep throat. Infectious mononucleosis, hepatitis, and colds may likewise result in hives.
How Are Hives Diagnosed?
In some cases, the trigger of hives is obvious. For example, if a person eats peanuts or shrimp and develops hives, the trigger of the hives is likely peanuts or shrimp. Other cases may require some investigation by the patient and their dermatologist, as there are many potential causes. If your hives have disappeared for a long period, it may be more difficult to identify the cause of your former outbreak. While a single episode of hives may not call for extensive testing, you may seek treatment or the advice of a skin specialist, such as those with Advanced Dermatology and Skin Cancer Center, or an allergist to help treat your symptoms and avoid further outbreaks. Please contact our office to learn about our available treatments for hives and schedule an appointment with our dermatologists.
Hives Treatment
Oftentimes, the first step in getting hives treatment is to figure out if you have hives. In most cases, your dermatologist can determine this by performing a physical exam on the affected skin. Your skin will show signs of welts associated with hives if you have them. Your dermatologist or practitioner may also perform blood or skin tests to determine the cause of your hives, especially if they result from an allergic reaction. If you are experiencing a mild case of hives unrelated to other health conditions, you may not require prescription treatment. In these cases, your practitioner may recommend temporary relief with the following.
- Antihistamines for hives
- Avoid irritating the affected area
- Avoid hot water, which can aggravate hives
- Taking a cool or lukewarm bath with colloidal oatmeal or baking soda
Can Hives Be Prevented?
Making simple lifestyle changes may help prevent hives from reoccurring in the future. If you have allergies and know what likely caused your allergic reaction, your doctor will suggest avoiding any possible exposure to these factors. Another option that can help you reduce the risk of experiencing hives again is allergy shots. If you have recently experienced a hives breakout, you should avoid being in high-humidity areas and wearing tight clothing.