Urticaria: Causes, Symptoms, and Appropriate Treatment

Urticaria is a skin condition that many people have experienced. Symptoms often appear as raised, red, itchy rashes that can occur on several areas of the body. This leads many people to wonder what causes urticaria, how it can be treated, how long it takes to resolve, and why it sometimes recurs. Some types of urticaria resolve quickly, while others may persist for a longer period. Understanding the underlying causes of urticaria can help you take appropriate care of yourself and manage the symptoms more effectively.

Key Takeaways

• Urticaria can be divided into two types: acute urticaria, in which symptoms occur and resolve within 6 weeks, and chronic urticaria, in which symptoms recur for longer than 6 weeks.
• The diagnosis of urticaria focuses on medical history-taking and blood tests. In cases where complications are suspected, special imaging techniques such as CT scans or MRI may be used to identify underlying causes.
• Treatment for urticaria includes antihistamines and avoiding triggering factors. If you have chronic urticaria, you should consult a doctor at the Skin and Plastic Surgery Center for specific treatment.

What Is Urticaria? Why Does the Skin Develop Raised, Itchy Rashes?

Urticaria is a type of skin condition that can occur in people of all ages and genders. It is characterized by raised, red, swollen rashes or welts with intense itching and may vary in size and shape.

What causes urticaria? Urticaria occurs as a result of the body's reaction, which causes an important chemical called histamine to be released from skin cells. This causes the blood vessels beneath the skin to dilate and fluid to leak into the skin layers, resulting in the raised swelling characteristic of urticaria. However, most urticarial rashes usually fade on their own within 24 hours without leaving any marks.

How Many Types of Urticaria Are There?

Urticaria, or hives, can be divided into two types based on the duration of symptoms: acute urticaria and chronic urticaria. These two types differ in their characteristics and course of the condition.

• Acute urticaria is a type of urticaria in which symptoms last for no more than 6 weeks. It usually presents with raised, red, itchy rashes and may resolve on its own within 1 week. In some cases, acute urticaria may become more severe, such as with swelling of soft tissues, known as angioedema, but in general, the symptoms can be managed and relieved.
• Chronic urticaria is a type of urticaria in which symptoms continue for more than 6 weeks and may occur several times a week for longer than 1 year. This type of urticaria often occurs without a clearly identifiable cause. In some cases, it may result from the body's response to triggering substances (allergens) or abnormalities in the immune system. Therefore, patients with chronic urticaria require close monitoring and appropriate treatment by a doctor.

What Causes Urticaria?

Urticaria does not result from a single factor but occurs as a reaction of the body to various external and internal triggers, causing cells to release histamine. Common causes of urticaria include:

• Food: Food allergies are a major cause of acute urticaria, particularly seafood, eggs, milk, nuts, and certain food additives.
• Medication: Certain groups of medications, such as antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), some pain relievers, and even medications used to control high blood pressure, such as ACE inhibitors, can trigger urticaria.
• Infection: Viral infections, such as the common cold, bacterial infections, fungal infections, or parasitic infections can trigger urticaria, particularly in children.
• Environmental Factors and Allergens: These include pollen, dust mites, animal dander, venom from insect bites or stings, and chemicals from direct contact.
• Physical Factors: Urticaria may be triggered by physical changes such as cold, heat, sunlight, pressure, vibration, or even sweating.
• Autoimmune Conditions and Other Illnesses: In cases of chronic urticaria with no identifiable cause, the condition may be associated with abnormalities of the body's immune system or other diseases, such as thyroid disease or lupus.

As for the question of what causes urticaria at night, it is often related to changes in body temperature or room temperature during the night, contact with bedding that may contain dust mites, or reactions to medication taken before bedtime. These factors may all trigger urticaria.

What Are the Symptoms of Urticaria?

Symptoms of urticaria may appear differently on the skin from person to person, ranging from mild itchy rashes to severe symptoms that affect other body systems. Common symptoms that patients may notice include:

• Raised Red or Pink Rashes: This is a distinctive characteristic of urticaria. The rash appears as raised, swollen patches on the skin, varies in size, and has clearly defined borders. When pressure is applied to the center of the rash, it temporarily becomes pale.
• Severe Itching: Urticaria is often accompanied by intense itching that may interfere with daily activities and sleep.
• Recurrent Symptoms: Individual urticarial rashes generally remain in the same area for no longer than 24 hours before gradually fading without leaving marks or scars. However, new rashes may continue to appear in other areas even after the original rash has disappeared, causing symptoms to continue for several days or weeks.
• Swelling of Soft Tissues: Some patients with urticaria may experience deeper swelling beneath the skin, known as angioedema. It commonly occurs around the lips, eyelids, tongue, genitals, hands, or feet. This type of swelling usually causes a feeling of tightness and pain rather than itching.
• Severe Allergic Reactions: A severe allergic reaction is a medical emergency that may occur together with urticaria. Symptoms indicating a severe reaction and requiring immediate treatment include rapid swelling of the tongue or throat causing difficulty breathing, or chest tightness accompanied by other symptoms such as dizziness, low blood pressure, or loss of consciousness. If these symptoms occur, seek medical attention as soon as possible.

Urticaria and Diagnosis

The diagnosis of urticaria mainly focuses on taking a detailed medical history and performing a physical examination to assess the rash. In cases of chronic urticaria or severe symptoms, additional tests may be required to identify the underlying cause. Doctors may diagnose urticaria using the following methods:

• Medical History and Physical Examination: The doctor will ask about the history of urticaria, whether it is acute or chronic, the duration of the rash, suspected triggers such as food, medication, or stress, as well as any history of other medical conditions to help narrow down the possible causes.
• Blood tests may be performed to assess levels of markers indicating inflammation or to identify abnormalities in internal organs, such as the liver or kidneys, or to test thyroid hormone levels in order to investigate possible causes of chronic urticaria.
• Skin Prick Test: This test is used to identify specific allergens that may cause acute urticaria, such as certain foods or pollen. An allergen extract is placed on the skin, and a small needle is used to prick the skin to observe the urticarial reaction.
• Challenge Tests: For patients with urticaria triggered by physical factors, such as cold or exercise, the doctor may directly expose the skin to the suspected trigger to confirm the type of urticaria.
• Radiological Examinations (CT Scan and MRI): Radiological examinations are not used to diagnose urticaria directly. However, in some cases where urticaria is suspected to result from an underlying internal condition or where severe angioedema affects internal organs, CT scans or MRI may be used to rule out other complications or identify an underlying condition causing the urticaria.

What Are the Treatment Options for Urticaria?

The main goals of urticaria treatment are to relieve itching and inflammation and prevent symptoms from recurring. The appropriate treatment depends on the type and severity of urticaria. Treatment options include:

• Antihistamines are the main treatment and a basic method for managing urticaria. These medications help inhibit the effects of histamine, which causes urticarial rashes and itching. The doctor may prescribe both sedating and non-sedating antihistamines at standard doses or at higher doses to control symptoms of chronic urticaria.
• Avoiding triggering factors is the most important part of managing urticaria. Patients should identify and avoid foods, medications, or environmental factors that trigger urticaria symptoms to help prevent recurrence.
• Corticosteroids may be used in cases where acute urticaria symptoms are very severe or when angioedema and severe allergic reactions (anaphylaxis) occur together. They are generally used for a short period to reduce severe inflammation associated with urticaria.
• Immunosuppressants and Biologics: For patients with chronic urticaria who do not respond to antihistamines even at higher doses, the doctor may consider biologic medications, such as omalizumab, or other immunosuppressive medications to provide long-term control of urticaria symptoms.
• Emergency Treatment: If a patient experiences a severe allergic reaction (anaphylaxis) associated with urticaria, the doctor will administer epinephrine and provide other supportive treatment to manage the emergency promptly.

When Urticaria Affects Your Daily Life, Praram 9 Hospital Stands by You with Specialist Care

Urticaria is a skin condition that can cause significant discomfort. Although most cases of acute urticaria can resolve on their own, patients should not ignore chronic urticaria or severe symptoms such as chest tightness. If complications are suspected and further investigation using specialized techniques such as CT scans or MRI is required, patients should seek medical treatment immediately.

If you have questions about urticaria symptoms or require an accurate diagnosis and comprehensive treatment, the Skin and Plastic Surgery Center, as well as the Allergy Center within the Pediatric Center at Praram 9 Hospital, are ready to provide appropriate care. Our dermatology specialists are available to provide consultation and closely develop a treatment plan for all types of urticaria.

For More Information

• Facebook: Praram 9 Hospital International & Expats
• Line: @Praram9Hospital
• Tel: 1270

Frequently Asked Questions About Allergies

1. Can Allergies Really Cause Dark Circles Under the Eyes?

Allergies can cause dark circles under the eyes, particularly in people with allergic rhinitis. Inflammation and swelling of the nasal cavity can affect blood circulation, causing blood to accumulate beneath the eyes and making the skin under the eyes appear darker than usual.

2. Are Allergies Considered a Chronic Medical Condition?

Allergies can be considered a chronic medical condition with symptoms ranging from mild to severe, particularly when symptoms are chronic or recur frequently. Symptoms often recur when the body comes into contact with allergens such as dust, pollen, or certain foods.

References

Jacqueline Eghrari-Sabe. (n.d.). What is Chronic Urticaria?. Allergy & Asthma Network. https://allergyasthmanetwork.org/chronic-urticaria/

American Academy of Allergy, Asthma & Immunology. (2025, October 2). Hives (Urticaria) and Angioedema Overview. https://www.aaaai.org/tools-for-the-public/conditions-library/allergies/hives-(urticaria)-and-angioedema-overview

ASCIA. (2024, June). Hives Urticaria. https://www.allergy.org.au/patients/skin-allergy/urticaria-hives