Amsel criteria for diagnosis of bacterial vaginosis

Amsel criteria for diagnosis of bacterial vaginosis (BV)
Sign	Homogeneous, thin, grayish-white discharge that smoothly coats the vaginal walls
Vaginal pH	Vaginal pH >4.5
Amine test	Positive whiff-amine test, defined as the presence of a fishy odor when a drop of 10% potassium hydroxide (KOH) is added to a sample of vaginal discharge
Saline microscopy	PMN:EC <1; loss of rods; increased coccobacilli; clue cells comprise at least 20% of epithelial cells (present in >90% of patients)

At least three Amsel criteria must be present to make the diagnosis of BV.

BV: bacterial vaginosis; EC: vaginal epithelial cell; PMN: polymorphonuclear cell.

Data from: Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep 2021; 70:1.

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