Final answer:
In the case of cellulitis of the right leg, a nurse would look for signs including reddening, warmth, and pain in the affected area, along with systemic symptoms such as fever and swelling. If the infection advances, as in Mark's case, it may progress to necrotizing fasciitis.
Step-by-step explanation:
When assessing a client with cellulitis of the right leg, a nurse would expect to find symptoms such as an area of the skin that is reddened, warm to the touch, and painful. The causative agent is often S. pyogenes, which can enter through a breach in the epidermal barrier such as a cut or abrasion. In the given scenario, the client, Mark, develops additional symptoms indicative of an advancing infection, including fever, swelling, and pus production, signaling possible progression to a condition called necrotizing fasciitis, which is more severe.