2 Cause Vaginal candidiasis is caused by a yeast, Candida albicans, a usually harmless inhabitant of the gastrointestinal tract, skin and vagina, which overgrows to cause infections when conditions allow. Oestrogen promotes the production of glycogen in the vaginal epithelium; the glycogen breaks down to glucose and lowers the pH of vaginal secretions promoting an environment favourable to the growth of Candida.

3 Predisposing factors: pregnancy; diabetes; broad-spectrum antibiotics; immuno-compromised status; immuno-suppressant drugs, including oral steroids; use of bath additives, vaginal deodorants and preparations for vulval pruritus containing local anaesthetics; wearing occlusive underwear.