What is the most likely diagnosis for a woman experiencing flushing and pustules primarily on her cheeks and chin after eating spicy foods?

The presentation described—flushing and pustules specifically located on the cheeks and chin that are triggered by consuming spicy foods—strongly aligns with the diagnosis of rosacea.

Rosacea is characterized by persistent facial redness, flushing, and the development of red bumps or pustules, particularly in sensitive areas such as the central face. Triggers for rosacea can include spicy foods, alcohol, temperature changes, and stress, which can exacerbate symptoms. The fact that the flushing and pustules occur after eating spicy foods suggests the presence of a flare-up related to known rosacea triggers.

Atopic dermatitis generally presents as itchy, inflammatory skin that can affect various body parts, often starting in childhood, and it is less likely to be associated specifically with flushing after eating. Lupus often has a broader systemic involvement and is associated with different cutaneous manifestations, such as a butterfly rash over the cheeks. Acne vulgaris is characterized by comedones and is more prevalent in younger individuals and typically does not present with flushing as a primary symptom. The distinct combination of flushing and pustules localized to the cheeks and chin after dietary triggers is what makes rosacea the most likely diagnosis in this scenario.