What condition is characterized by swelling and irritation of an epicondyle?

Epicondylitis is the condition that involves swelling and irritation of an epicondyle, which is a bony prominence on the surface of a bone, typically located near a joint. This condition usually affects the elbow and is commonly associated with repetitive movements that strain the muscles and tendons around the elbow, leading to inflammation.

In the case of epicondylitis, the most common presentations are medial epicondylitis (often called golfer's elbow) and lateral epicondylitis (often referred to as tennis elbow). Both conditions are characterized by pain and tenderness around the affected epicondyle, and they result in discomfort during certain movements.

The other terms provided, such as epiphysis, epistaxis, and erythema, refer to different medical concepts. An epiphysis is the end part of a long bone, involved in joint formation and growth. Epistaxis refers to nosebleed, which is unrelated to joint or tendon involvement. Erythema relates to redness of the skin, usually as a result of inflammation or infection, but does not specifically denote swelling or irritation of bony structures like epicondyles. Hence, understanding the specific context of epicondylitis clarifies why it is the correct answer