A number of factors have been implicated as triggers for episodes of vulvovaginal candidiasis. However, apart from antibiotics, pregnancy and poorly controlled diabetes, CKS found that the evidence to support individual risk factors is inconclusive.

Accepted risk factors for vulvovaginal candidiasis:

• Antibiotics:
• Vulvovaginal candidiasis occurs in about 30% of women taking a course of systemic or intravaginal antibiotics. No antibiotic has been identified as having a low risk for vulvovaginal candidiasis [Sobel, 2007].
• Only women who are already colonized with Candida are at risk of vulvovaginal candidiasis following treatment with antibiotics [Sobel, 2007].
• Pregnancy:
• During pregnancy, asymptomatic vaginal colonization with Candida, acute vulvovaginal candidiasis, recurrent infection, and treatment failure are all more common [Sobel, 2007].
• Diabetes mellitus (poorly controlled):
• Poorly controlled diabetes predisposes to symptomatic vulvovaginal candidiasis [Sobel, 2007].
• Vulvovaginal candidiasis is not more frequent in women with well controlled diabetes [Sobel, 2007].
• Women without diabetes who have recurrent vulvovaginal candidiasis tend to have substantially higher plasma glucose levels (but still within the normal range) [Sobel, 2007].
• Immunocompromised status, such as HIV/AIDS:
• Vaginal colonization and vulvovaginal candidiasis are more common in women with HIV/AIDS. The risk increases with, longer time since diagnosis, lower CD4 count, and higher HIV viral load [Duerr et al, 2003; Ohmit et al, 2003].
• In women with HIV/AIDS, oral candidiasis is more likely to be a problem than vulvovaginal candidiasis [Ohmit et al, 2003].
• Although vulvovaginal candidiasis is more common among HIV-infected women, it is no more severe in this group than in women without HIV [Duerr et al, 2003].

Possible risk factors for vulvovaginal candidiasis:

• Contraceptives:
• It is a commonly held view that contraceptives, especially combined oral contraceptives, increase the risk of vulvovaginal candidiasis. There are many studies of the various contraceptive methods, but all have methodological weaknesses and the results are inconsistent [Sobel, 2007].
• Sexual behaviours:
• Although the incidence of vulvovaginal candidiasis increases greatly during the years of peak sexual activity, CKS found only weak evidence that sexual behaviours influence transmission, and no good evidence of benefit from treating sexual partners.
• Women receiving oral sex may be at greater risk of vulvovaginal candidiasis [BASHH, 2002; Mardh et al, 2002; Sobel, 2007].
• Treatment of asymptomatic male sexual partners is not advocated by guidelines (such as [CDC, 2006; RCGP and BASHH, 2006]) as there is little evidence of benefit.
• Tight-fitting clothing:
• Wearing tights or using pantyliners was found to be a risk factor for vulvovaginal candidiasis in one small observational study [Patel et al, 2004].
• Female hygiene and sanitation:
• Sanitary towels: CKS found limited evidence that sanitary towels may increase the risk of vulvovaginal candidiasis [Mardh et al, 2002].
• Tampons: CKS found no evidence that tampons cause vulvovaginal candidiasis [Mardh et al, 2002].
• Vaginal douching: CKS found no evidence that douching increases the likelihood of vulvovaginal candidiasis [Mardh et al, 2002].