What is the most likely diagnosis for a patient with facial flushing and pustules aggravated by spicy foods?

The most likely diagnosis for a patient presenting with facial flushing and pustules, particularly when these symptoms are aggravated by spicy foods, is rosacea. Rosacea is a chronic skin condition that primarily affects the face and is characterized by a variety of symptoms, including persistent facial redness (flushing), visible blood vessels, and often the emergence of small, red, pus-filled bumps (pustules). Triggering factors for rosacea frequently include hot or spicy foods, alcohol, and extreme temperatures, making it particularly sensitive to dietary and environmental changes.

In contrast, atopic dermatitis typically presents with dry, itchy skin and often involves other areas of the body, such as flexural surfaces, rather than being localized primarily to the face. Lupus can cause a rash, but it usually presents differently, with a characteristic butterfly-shaped rash across the cheeks and nose, and is often accompanied by systemic symptoms. Acne vulgaris is generally related to comedones (blackheads and whiteheads), and while it can cause pimples, it does not typically feature flushing or sensitivity triggered by food intake in the same way that rosacea does.

Thus, given the symptoms of flushing and pustules that worsen with spicy foods, rosacea is the most fitting diagnosis.