What is a common symptom of a bacterial skin infection?

A common symptom of a bacterial skin infection is characterized by localized redness, swelling, and often the presence of pus. This occurs because bacteria invade the skin and trigger an inflammatory response from the body's immune system. The inflammation manifests as redness due to increased blood flow to the area, swelling as fluid accumulates, and pus which is made up of dead white blood cells, bacteria, and tissue debris, indicating an active infection.

The other options represent symptoms associated with different skin conditions or infections. Itchy rashes usually occur with allergic reactions or viral infections but not consistently with bacterial skin infections. Dry and flaky skin is often a sign of skin conditions such as eczema or psoriasis, rather than a bacterial infection. Sudden hair loss in patches, known as alopecia areata, is not typical of a bacterial skin infection and is usually related to autoimmune conditions. Thus, the distinctive combination of redness, swelling, and pus is vital in identifying a bacterial skin infection.