5.            Differential diagnosis

·       Bacterial vaginosis: vaginitis caused by a combination of bacterial species usually present at low counts in the vagina, which when present at higher levels disrupt the normal flora and cause infection. Discharge may be confused with thrush, but it is white and watery with a strong 'fishy' odour. Itching is a less prominent feature than in candidiasis.

·       Trichomoniasis: a sexually transmitted disease caused by a protozoan parasite, Trichomonas vaginalis. As in thrush, there is vulvar itching, but discharge is profuse, frothy, yellow-green in colour and with an unpleasant odour.

·       Cystitis: with thrush, discomfort when urinating may be confused with dysuria associated with cystitis. However, in thrush the discomfort and burning are in the external vaginal area rather than in the bladder and urethra, as in cystitis.

·       Atrophic vaginitis: in postmenopausal women lack of oestrogen reduces vaginal resistance to infection and injury, which can produce similar burning and itching symptoms to thrush, but thrush is uncommon in postmenopausal women.

·       Adverse drug reactions: drugs that can predispose to thrush include broad-spectrum antibiotics, corticosteroids and drugs that can affect oestrogen levels, including oral contraceptives, hormone replacement therapy, tamoxifen and raloxifene.