There are two stages to the development of an allergic reaction: acute and late-phase reaction. The body's reaction depends a lot on the phase and how far chemical mediation has progressed.
Allergy pathophysiology
Anaphylaxis pathophysiology
Drug allergy pathophysiology
Cellulitis pathophysiology
Stevens-Johnson syndrome pathophysiology
Gangrene pathophysiology
Endocarditis pathophysiology
Sarcoidosis pathophysiology