What condition is indicated by burning under the breast and malodorous discharge in an older female?

The described symptoms of burning under the breast and the presence of malodorous discharge in an older female point towards intertrigo. This condition typically occurs in warm, moist areas of the body where skin surfaces rub together, such as under the breasts, in the groin, or between skin folds. The friction and moisture can lead to inflammation, irritation, and sometimes secondary infections due to the accumulation of sweat and skin debris, creating an environment conducive for bacterial and yeast overgrowth.

In older women, especially those who may have larger breast tissue, the friction and moisture retention under the breast can result in intertrigo, characterized by a burning sensation and odor due to the breakdown of the skin and the activity of microbes. This aligns well with the symptoms presented.

Conditions like cellulitis typically present with signs of acute infection and localized redness or swelling, while fungal infections may cause a distinct rash but are less likely to present with significant malodorous discharge without other notable signs. Dermatitis encompasses a broader category of skin irritations, which might not specifically relate to the moisture and friction experienced in intertrigo. Thus, intertrigo is the most appropriate diagnosis in this scenario based on the given symptoms.