Vaginal Candidiasis: This is a common condition in girls, especially after antibiotic use, which can disrupt the normal vaginal flora and lead to an overgrowth of Candida. The symptoms of vaginal itching and discharge are consistent with this diagnosis.

Bacterial Vaginosis: Although less common in prepubertal girls, bacterial vaginosis can occur and cause similar symptoms. The recent use of antibiotics could have altered the vaginal flora, making this a possible diagnosis.
Vaginal Foreign Body: In young girls, the insertion of a foreign body into the vagina can cause irritation, discharge, and itching. This should be considered, especially if the discharge is foul-smelling.
Allergic or Irritant Dermatitis: Exposure to soaps, bubble baths, or other irritants can cause vaginal itching and discharge in girls.

Sexual Abuse: Although not likely, it is crucial to consider the possibility of sexual abuse in any child presenting with genital symptoms. A thorough and sensitive evaluation is necessary.
Streptococcal Infection: Group A beta-hemolytic streptococcal infection can cause vulvovaginitis, characterized by itching, burning, and discharge. This condition requires prompt antibiotic treatment.
Gonococcal or Chlamydial Infection: These sexually transmitted infections, although rare in this age group, can cause severe consequences if not treated promptly.

Lichen Sclerosus: A chronic skin condition that can cause itching and discharge, although it is less common in this age group and typically presents with more skin changes.
Vaginal Tumors: Extremely rare in children, but any persistent or unusual symptoms should prompt further investigation to rule out such conditions.