Causes and clinical symptoms of acute allergic urticaria

Acute allergic urticaria has a rapid and acute onset with very obvious symptoms. Allergic symptoms may occur in various parts of the body. When the disease occurs, it can feel extremely itchy and round wheals of varying sizes will appear on the body. Generally, it will last for half an hour to an hour and then disappear on its own. What are the causes of acute allergic urticaria?

1. Causes

1. Food: Animal protein such as fish, shrimp, crab, meat, and eggs are the most common, followed by certain plant foods such as strawberries, apples, peaches, grapes, pineapples, and nettles.

2. Drugs: They can be divided into two categories. One is drugs that can form antigens, such as penicillin, serum, etc., and the other is histamine releasers, such as aspirin, morphine, etc.

3. Various infectious factors can cause this disease.

4. Inhalants: pollen, dust, animal dander, smoke, feathers, fungal spores, volatile chemicals (such as formaldehyde, acrolein, etc.) and other airborne allergens.

5. Animal and plant factors: such as insect bites, piercing of poisonous hairs (such as caterpillars, beetles and moth scales piercing the skin) and contact with hemp, wool, etc.

6. Physical factors: cold, heat, sunlight, friction, pressure, etc.

7. Mental factors: Mental tension or excitement, and exercise can cause the release of acetylcholine. Genetic factors: Some types of urticaria are related to genetics, such as familial cold urticaria, hereditary familial urticaria syndrome, etc.

8. Systemic diseases: rheumatic fever, SLE, hyperthyroidism, malignant tumors, etc.

2. Symptoms

1. The serum infiltrates rapidly in the microvessels, compressing the wall of the microvessels. The wheals may appear pale white, and the pores on the surface are obvious like orange peel.

2. In acute allergic urticaria, the edema will decrease within a few hours, the wheals will turn into erythema and gradually disappear, but new wheals will occur one after another, and may occur multiple times within a day.

3. Severe cases may have symptoms of anaphylactic shock such as palpitations, irritability, nausea, vomiting, and even low blood pressure. Some patients may have gastrointestinal involvement and mucosal edema.

4. When the wheal occurs, there is abdominal pain, which is sometimes very severe and resembles acute abdominal pain. Diarrhea may also occur, accompanied by tenesmus and loose mucus stools. If the laryngeal mucosa is involved, there will be difficulty breathing and even suffocation.