Final answer:
The patient with red and white oral lesions after long-term antibiotic use most likely has oral candidiasis (thrush), which is treated with antifungal medications.
Step-by-step explanation:
A patient who has been on broad-spectrum antibiotics for 4 weeks and presents with widespread, sore, red, and white oral mucosal lesions is most likely suffering from oral candidiasis. Antibiotics can disrupt the normal flora of the mouth, giving rise to opportunistic infections such as candidiasis, commonly known as thrush. The condition is characterized by white patches and pseudomembranes and is often treated with topical antifungal agents like nystatin or clotrimazole, though systemic treatment with azole antifungals such as fluconazole may be necessary for severe cases.
White lesions in the mouth are typical of oral thrush, an overgrowth of Candida yeast, which can be diagnosed through clinical observation and confirmed through culture and susceptibility testing for antifungal agents. Topical or systemic azoles are the usual treatments, with repeat infections being a common issue that can be mitigated by following treatment recommendations and practicing good hygiene.