Does allergy always cause itching? What are the symptoms of allergy?

Allergies are very common in our lives. People with allergies will have allergic reactions after coming into contact with allergens. So, does allergies always cause itching?

Does allergy always cause itching?

Allergies do not necessarily cause itching. Allergies are abnormal or pathological reactions to certain substances (such as bacteria, pollen, food or drugs), situations (such as mental or emotional excitement or exposure to sunlight) or physical conditions (such as cold). When the body's resistance to antigen invasion is too strong, an allergic reaction will occur under the stimulation of allergens.

Symptoms of allergy:

1. Allergic shock reaction:

(1) Symptoms of respiratory obstruction: caused by laryngeal edema, tracheal and bronchial spasms, and pulmonary edema. Symptoms include chest tightness, palpitations, a feeling of throat obstruction, difficulty breathing, and flushed face, accompanied by a sense of danger, dry mouth, dizziness, and numbness of the face and limbs.

(2) Symptoms of microcirculatory disorders: caused by extensive dilation of microvessels. Symptoms include pale complexion, irritability, chills, cold sweats, weak pulse, and decreased blood pressure.

(3) Central nervous system symptoms: caused by lack of oxygen to the brain. Manifestations include loss of consciousness, coma, convulsions, and incontinence.

(4) Skin allergies: such as itching, urticaria and other various rashes.

2. Hematologic disease-like reactions. The differentiation of this group of reaction types mainly depends on the changes in blood test results. The main symptoms include: granulocytopenia or agranulocytosis, thrombocytopenia, aplastic anemia, hemolytic anemia, and megaloblastic anemia.

3. Serum sickness-like reaction. The reaction symptoms are mainly serum sickness-like changes, with sudden widespread erythema and urticaria-like rash common clinically, and may be accompanied by fever, joint pain and lymphadenopathy.