Vulvovaginal Candidiasis

Vulvovaginal candidiasis is inflammation of the vulva and vagina caused by overgrowth of yeasts of the genus Candida, most commonly Candida albicans. It is a frequent cause of vulvovaginal itching, irritation, and discharge in women, and it represents an overgrowth of a commensal organism rather than a sexually transmitted infection.

Definition

Vulvovaginal candidiasis is a symptomatic inflammation of the vulvar and vaginal mucosa caused by overgrowth of Candida species, predominantly Candida albicans, in the genital tract.

Scope

The entry covers the fungal aetiology of the condition, its typical clinical features, the distinction between uncomplicated and recurrent or complicated forms, and the predisposing factors that favour Candida overgrowth. It is a reference description of the entity and does not provide diagnostic or treatment instructions.

Core questions

• Which organisms cause vulvovaginal candidiasis, and why is it considered an overgrowth rather than a transmitted infection?
• What clinical features characterise the condition?
• What distinguishes uncomplicated from recurrent or complicated candidiasis?
• Which host factors predispose to Candida overgrowth?

Key concepts

• Candida albicans and non-albicans species
• Commensal overgrowth rather than sexual transmission
• Inflammatory vulvovaginitis (itching, erythema, discharge)
• Uncomplicated versus complicated candidiasis
• Recurrent vulvovaginal candidiasis
• Predisposing host factors
• Normal vaginal pH (typically unchanged)

Mechanisms

Candida species, chiefly Candida albicans, can colonise the vagina as commensals without causing symptoms. Disease arises when the balance between the host and the organism shifts in favour of fungal overgrowth and tissue invasion, provoking an inflammatory response in the vulvovaginal mucosa that produces itching, erythema, and a characteristic discharge (Sobel, 2007). Factors that promote overgrowth — such as conditions that alter host defences or the local environment — predispose to symptomatic infection. Unlike bacterial vaginosis, the vaginal pH usually remains within the normal range (Sobel, 2007; ACOG, 2020).

Clinical relevance

Vulvovaginal candidiasis is clinically relevant because it is one of the most common causes of vulvovaginal symptoms; most cases are uncomplicated, but a minority of women experience recurrent or complicated disease that is more difficult to manage and that may involve non-albicans species (Sobel, 2007). This entry describes the spectrum of disease for orientation and is not a basis for individual diagnosis or treatment.

Epidemiology

Candidiasis is one of the most frequent causes of vaginitis in reproductive-age women, and a large proportion of women experience at least one episode during their lifetime; a smaller subset experience recurrent disease defined by multiple episodes within a year (Sobel, 2007; ACOG, 2020).

Evidence & guidelines

Comprehensive narrative review summarises the microbiology, classification, and clinical features of the condition (Sobel, 2007), and professional guidance from ACOG and the CDC frames its evaluation and the distinction between uncomplicated and complicated disease (ACOG, 2020; Workowski, 2021). This entry reports these sources for orientation rather than reproducing their recommendations.

Debates

How should recurrent vulvovaginal candidiasis be understood?

Recurrent disease, conventionally defined by several episodes within a year, behaves differently from sporadic infection and is more often associated with host susceptibility and, in some cases, non-albicans species; its pathophysiology and optimal classification remain areas of active discussion.

Seminal works

• sobel-2007
• acog-vaginitis-2020

Frequently asked questions

Is vulvovaginal candidiasis a sexually transmitted infection?

No. It results from overgrowth of Candida yeasts that can normally live in the genital tract as commensals, rather than from a pathogen acquired through sexual contact, although it produces symptomatic vulvovaginal inflammation.

What is the difference between uncomplicated and complicated candidiasis?

Uncomplicated candidiasis describes sporadic, mild-to-moderate disease, typically due to Candida albicans in otherwise healthy women, whereas complicated disease includes severe, recurrent, or non-albicans infection or infection in women with predisposing host factors.