Final answer:
Vasculitis is the inflammation of blood vessels and can lead to petechiae. Common types are related to immune complex diseases such as glomerulonephritis, rheumatoid arthritis, and systemic lupus erythematosus, which involve damaging immune reactions. Type II hypersensitivity and Hereditary Angioedema are additional forms of vasculitis.
Step-by-step explanation:
Types of Vasculitis
Vasculitis involves inflammation of the blood vessels and can lead to several health issues. Vasculitis can cause blood to leak from damaged vessels, forming purple spots called petechiae. There are various types of vasculitis, some of the most common forms being associated with immune complex diseases seen in conditions such as glomerulonephritis, rheumatoid arthritis, and systemic lupus erythematosus (SLE). In SLE and rheumatoid arthritis, harmful Type III hypersensitivity reactions occur when auto-antibodies form immune complexes with self antigens, which can damage tissues and organs, particularly the kidneys and joints.
Other forms of vasculitis can result from hypersensitivities, such as Type II, which is IgG-mediated and can occur during mismatched blood transfusions, and Hereditary Angioedema which is due to a deficiency in C1 esterase inhibitors affecting the complement system.