Vulvovaginal candidiasis: This is a common condition caused by a yeast infection, leading to symptoms such as itching, burning, and redness in the vaginal area. The external vagina burning sensation is a hallmark symptom, making it the most likely diagnosis.

Bacterial vaginosis: An imbalance of naturally occurring bacteria in the vagina can cause symptoms like burning, itching, and abnormal discharge.
Urinary tract infection (UTI): While primarily affecting the urinary system, UTIs can cause burning sensations in the genital area, especially during urination.
Vulvar dermatitis: Skin conditions like eczema or contact dermatitis can cause burning, itching, and redness in the vulvar area.
Sexually transmitted infections (STIs): Certain STIs, such as herpes or gonorrhea, can cause burning sensations in the genital area.

Herpes simplex virus (HSV): Although less common, HSV can cause severe symptoms, including burning, and can have significant consequences if left untreated.
Pelvic inflammatory disease (PID): A serious condition that can cause burning sensations, PID requires prompt treatment to prevent long-term complications.
Vulvar cancer: Although rare, vulvar cancer can cause burning sensations and must be ruled out to ensure proper treatment.

Lichen sclerosis: A rare skin condition that can cause burning, itching, and scarring in the vulvar area.
Vulvar vestibulitis: A condition characterized by chronic pain and burning in the vulvar area, often associated with intercourse.
Neurological disorders: Certain conditions, such as neuropathy or nerve damage, can cause burning sensations in the genital area, although these are relatively rare.