A woman experiences painful mouth lesions triggered by spicy food. What is the most likely diagnosis?

The woman's experience of painful mouth lesions that are triggered by spicy food strongly suggests the diagnosis of aphthous ulcers, commonly known as canker sores. These ulcers are characterized by their painful nature and can be exacerbated by certain foods, particularly those that are spicy or acidic.

Aphthous ulcers typically appear as round, shallow lesions with a gray or whitish base and a red halo. They commonly occur on the movable tissues of the mouth, such as the inside of the lips and cheeks, and can be recurrent in nature. The exact cause of these ulcers is not fully understood, but they are thought to be associated with various factors, including stress, dietary deficiencies, or immune responses.

In contrast, other conditions like candidiasis would present as white patches that can be scraped off, geographic tongue involves a map-like appearance of the tongue, and Koplik spots are characteristic of measles, presenting as small white spots on the mucosa, typically appearing before the rash. Each of these conditions presents with distinct symptoms and characteristics that do not align with the description of painful mouth lesions specifically triggered by certain foods. Hence, the presence of painful lesions that are aggravated by spicy foods leads to the conclusion that aphthous ulcers are the most likely diagnosis