February 2, 2023

Facial swelling may occur in diseases characterized by fluid retention, such as heart failure, kidney disease, and liver failure. In these conditions, the body cannot eliminate fluid adequately, and fluid accumulates in the face.
Facial swelling may also be due to allergy. It is usually sudden, and may or may not be accompanied by itchiness. Facial swelling or angioedema occurs because the walls of the smallest arteries and veins become inflamed and leaky, allowing fluid passage from inside blood vessels to the surrounding tissue.
Allergens include food, drugs, latex, exercise, pollens, and other substances. Angioedema is a common component of anaphylaxis or severe allergy. The face is one commonly affected area because the tissue surrounding the blood vessels are considered to be of “low resistance”.
Mast cells and bradykinins mediate allergic reactions. Upon activation, mast cells release substances called inflammatory mediators, and these are heparin, histamine, leukotriene C4, and prostaglandin D2 the substances that cause dilatation and leakiness of the small blood vessels.
Treatment of facial swelling due to fluid retention involves treatment of the underlying medical illness. It may include diuretics, fluid restriction, and salt restriction.
Treatment of facial swelling due to allergies entails the use of antihistamines with or without steroids. Treatment of anaphylaxis, which is a life-threatening condition due to inflammation of the larynx, entails the use of epinephrine.

When our body is exposed to infective agents – be it viruses or bacteria – our immune system will always mount a reaction – a normal or so-called physiologic protective mechanism to defend our body from being harmed.
This immune reaction is either innate/inborn or acquired. Acquired immunity develops after a naturally-acquired infection like when a person develops chickenpox after being exposed to a person with shingles or chickenpox itself.
Acquired immunity may also be initiated through immunization. A person is exposed to a controlled dose of antigen to incite the production of protective antibodies.
The duration of the protection conferred by natural infections and vaccinations cannot be easily predicted, and it would take months of observation and several studies to assess the protective immunity.
For the Covid-19 vaccines, the duration of immune protection is not yet known. There are two new studies which suggest that immunity may last for one year and possibly lifetime.
Reactions to these vaccines also involve mast cells and other immune system body cells.