What are the allergic reactions?

Many people in life suffer from allergies. These people have allergic constitutions. They are prone to allergies after eating seafood in daily life, and then they will vomit, have diarrhea, abdominal pain, and their skin will also be itchy. Some people develop allergic rhinitis or asthma after inhaling dust or powder, and some people are allergic to drugs. Let's take a look at the common reactions of allergies.

Clinical manifestations of allergic reactions:

1. Anaphylactic shock reaction:

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

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

(3) Central nervous system symptoms: caused by brain hypoxia. Symptoms include loss of consciousness, coma, convulsions, and incontinence.

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

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

3. Serum sickness-like reaction. The main reaction symptoms are serum sickness-like changes, and the common clinical manifestations are sudden widespread erythema and urticaria-like rash, which may be accompanied by fever, joint pain and lymphadenopathy.

4. Other systemic reactions. Most skin and mucous membrane rashes caused by drugs belong to this type. The clinical manifestations are varied. The common allergic drug eruptions include: fixed drug eruption, epidermolysis bullosa, exfoliative dermatitis drug eruption, eczematous dermatitis drug eruption, erythema multiforme and severe erythema multiforme drug eruption, photosensitivity drug eruption, etc.