Urticaria or the symptom “hives” is a common condition found in all ages and genders that many people are familiar with or have experienced. Urticaria can be caused by various factors. The distinctive characteristic of the disease is the presence of red rashes or raised red patches that are clearly visible and accompanied by itching. These symptoms usually appear all over the body, but some cases may only affect certain parts of the body. Similarly, some cases last only a few hours and then disappear, while others may occur daily or persist for years, which is called “chronic urticaria”.
Causes and Factors of Urticaria
Urticaria can be caused by many factors. It may result from allergies to certain substances through ingestion, contact, inhalation, or injection into the body. The main causes of urticaria can be categorized as follows:
Foods That Cause Urticaria
There are many types of foods that can cause urticaria, such as
- Protein-rich foods such as shrimp, fish, shellfish, eggs, nuts, milk, or even fruits
- Food additives or snacks such as food coloring, especially yellow or green colors often using Tartrazine, found in sweets like salim, kanom duang, puffed rice, candied winter melon, Chinese tea, layered desserts, sweetened beans, crispy jelly, khlong kraeng, lollipops, and crispy foi thong
- Certain vegetables and fruits containing salicylates, which can trigger urticaria, such as apples, cucumbers, potatoes, tomatoes, limes, black pepper, oranges, etc.
- Foods and drinks containing yeast, such as bread, liquor, and beer
Food allergy-induced urticaria is the most common, so it is important to carefully observe and identify the allergic cause from food intake to avoid it.
Medications That Cause Urticaria
Medications are another important cause of urticaria, which may occur immediately after taking the drug, such as
- Antibiotics, especially penicillin and sulfa drugs
- Painkillers and sleeping pills
- Contrast agents used in X-ray examinations
- Certain vitamins
Allergic reactions after injection or ingestion of medication are usually easy to observe, but in some cases, it may take 7-10 days, making it difficult to detect the allergy.
Insects That Cause Urticaria
Urticaria can be caused by contact or insect bites/stings, such as
- By contact, such as cat mites, dog mites, bird mites, and chiggers
- By bites or stings, such as bees, wasps, hornets, fire ants, and red ants
Sometimes, symptoms can be severe, including urticaria, swelling all over the body, or shock. Some cases may result in death shortly after being stung.
Weather That Causes Urticaria
- Sunlight: Some patients may develop urticaria when exposed to sunlight at certain times of the day, which involves specific wavelengths. When exposed, rashes may appear. This can be managed by avoiding sun exposure during those times or using sunscreen.
- Cold: Exposure to cold air or cold water, or consuming ice, may cause swelling in the neck area, difficulty breathing, or may be related to certain diseases such as syphilis or lymphoma.
- Airborne substances: Dust, airborne fungi, pollen, and animal dander when inhaled in large amounts may trigger urticaria.
Other Factors That Cause Urticaria
- Sweat Some people develop urticaria after heavy exercise or excessive sweating. This type of urticaria usually appears as small bumps on the arms and legs more than on the torso.
- Emotions and Mental State In some cases, urticaria occurs after emotional disturbances such as anger, stress, or anxiety, often resulting in chronic urticaria.
- Scratching Caused by friction on the skin. Some patients have sensitive skin that reacts to scratches by developing raised itchy marks within minutes. Scratching and itching further increase the marks and itching.
- Infections can also cause urticaria.
- Intestinal parasites are a common cause, such as roundworms, flatworms, and amoebas.
- Infections in other parts of the body such as vaginal fungal infections
- Tooth decay can also be a cause of urticaria. Treating or extracting decayed teeth may relieve urticaria symptoms in some patients.
- Other underlying diseases Some diseases can cause urticaria, such as lymphoma.
Urticaria can result from many causes. Symptoms range from mild, such as food allergies, to being part of serious diseases. Generally, urticaria is not severe and may resolve on its own once the allergen is removed from the body. However, if the patient has chronic symptoms, a thorough examination should be conducted to find the cause and receive appropriate treatment. The doctor will take a detailed history, perform a physical examination, and conduct laboratory tests such as blood, urine, stool tests, or chemical analysis in the blood. Some cases may require skin allergy testing as well.