What is the term for any pus-forming skin disease?

The term "pyoderma" specifically refers to any pus-forming skin disease. It derives from the Greek words "pyon," meaning pus, and "derma," meaning skin. Pyodermas can arise from various bacterial infections, leading to inflammation, redness, and the development of pus within the affected skin areas. Conditions classified as pyodermas can include impetigo and folliculitis, among others, highlighting the primary characteristic of pus formation.

In contrast, the other terms provided refer to distinct conditions or symptoms unrelated to pus-forming skin diseases. Myalgia refers to muscle pain, lesion denotes a pathological change or injury in tissue, and mumps is a viral infection characterized by swelling of the salivary glands. Thus, pyoderma is the appropriate term for any condition involving pus formation on the skin.