Vulvovaginal candidiasis

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

Vulvovaginal candidiasis is diagnosed when compatible vulval or vaginal inflammation occurs with Candida support. Candida may also live in the vagina without causing disease, so a laboratory report is not a treatment instruction and population screening for colonisation does not improve care.

The symptom pattern often centres on itch, burning, soreness, superficial dyspareunia or external dysuria. Erythema, oedema, excoriation and fissuring may be more useful than discharge, which can be thick, thin or absent. Vaginal pH usually remains 4.5 or below because the lactobacillus-dominated environment is not replaced in the way seen with bacterial vaginosis.

A single uncomplicated episode and a recurrent syndrome require different levels of proof. Microscopy can connect symptoms to yeast during an acute visit. Repeated, severe or treatment-resistant symptoms require culture, species identification and a fresh examination because non-albicans Candida, azole exposure, dermatitis, vulval dermatosis and vulvodynia can all change the plan.

Recurrent VVC means at least four symptomatic episodes in a year, with microbiological confirmation built into the definition. A remembered history of repeated “thrush” after remote or over-the-counter treatment is insufficient. Confirming episodes protects patients from long suppressive courses when the true problem is irritant skin disease or another infection.

Treatment choice is shaped by pregnancy, preference, interactions and whether disease is uncomplicated. Topical and oral azoles are similarly effective for many acute episodes, but pregnancy directs care to a longer topical imidazole course and away from oral azoles. Confirmed recurrent C. albicans disease may need induction followed by maintenance, while non-albicans or refractory disease needs specialist microbiological advice.

Bacterial vaginosis is a differential comparator rather than a second subject here. Thin homogeneous malodorous discharge, little inflammation, pH above 4.5 and clue cells point away from VVC. Prominent itch, fissuring or vulval swelling should not be explained by BV without looking for Candida, trichomoniasis, dermatitis or mixed disease.

Key points

VVC is an inflammatory syndrome: itch, soreness, burning, erythema, oedema or fissuring matters more than whether discharge looks curdy.
No symptom or discharge appearance is diagnostic; inspect persistent or atypical disease and consider dermatitis, dermatosis, herpes, vulvodynia, trichomoniasis and cervical infection.
Use microscopy to support symptomatic infection, and interpret culture with the examination because Candida growth without symptoms is colonisation.
Call disease recurrent only after at least four symptomatic episodes in 12 months, including at least two microbiologically confirmed episodes and at least one positive culture.
For suitable non-pregnant adults with uncomplicated disease, a topical imidazole or a single oral fluconazole dose can be selected after contraindications and interactions are checked.
During pregnancy use an intravaginal topical imidazole course, generally up to seven nights; avoid oral azoles during pregnancy, pregnancy risk and breastfeeding.
Obtain fungal culture with species identification for recurrent, refractory or suspected non-albicans disease before assuming azole resistance.
VVC is usually endogenous overgrowth, so routine treatment of an asymptomatic sexual partner is not indicated.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

Endogenous Candida overgrowth

Most episodes arise when Candida already present in the genital tract becomes associated with symptomatic inflammation, rather than after acquisition as a conventional STI.

Host and environmental modifiers

Pregnancy, recent antibiotics, diabetes, immune compromise and individual mucosal susceptibility can favour symptomatic disease, but no single factor is present in every patient.

Non-albicans species

Candida species other than C. albicans occur less often, may be less responsive to standard azoles and are especially important when cultures and symptoms remain concordant after treatment.

Iatrogenic symptom persistence

Repeated antifungals, fragranced washes and topical remedies can irritate vulval skin, making a resolved infection appear to be continuing disease.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Superficial mucosal inflammation
Yeast adhesion and filamentation provoke epithelial and neutrophil responses, generating marked itch, burning, swelling and fissures without an ascending pelvic infection.
2
Preserved vaginal acidity
Lactobacillus dominance is usually retained during VVC, so pH commonly stays at or below 4.5 despite substantial symptoms.
3
Colonisation without inflammation
Candida can be cultured when epithelial and host responses are not producing disease, which explains why screening and treatment of asymptomatic carriage are unhelpful.
4
Relapse and repeated episodes
A susceptible host may experience new inflammatory episodes after apparently successful short treatment; confirmation is needed to distinguish true fungal recurrence from persistent non-infective symptoms.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

Inflammatory Candida phenotype

Vulval itch or burning with soreness, erythema, oedema, excoriation or fissures and a non-offensive discharge supports VVC; discharge texture alone is unreliable.

Severe episode

Extensive erythema, marked oedema, excoriation and fissuring indicate greater inflammatory burden and justify examination, microbiological support and a review of host modifiers.

Recurrent vulvovaginal candidiasis

At least four symptomatic episodes within 12 months, with the required microbiological confirmation, defines a recurrence problem that should be assessed before maintenance treatment.

Possible non-albicans or resistant disease

Persistent symptoms after correctly used therapy, especially with recurrent positive cultures, prompts species identification and susceptibility advice while the clinician rechecks for a non-fungal diagnosis.

Bacterial vaginosis as a comparator

A fishy odour, thin homogeneous discharge, minimal visible inflammation, raised pH and clue cells favour BV; marked soreness and fissuring should keep VVC or another inflammatory disorder in view.

Red flags requiring action

Fever, lower abdominal pain, cervical excitation or adnexal tenderness is not explained by uncomplicated VVC and requires a pelvic-infection and emergency differential.
Collapse, shoulder-tip pain, bleeding or significant abdominal pain when pregnancy is possible requires urgent ectopic-pregnancy assessment.
Rapidly spreading erythema, tissue necrosis, marked oedema, ulceration or inability to pass urine demands examination for severe infection or another vulval process.
Postcoital, intermenstrual or postmenopausal bleeding needs cervical and cancer-focused assessment rather than attribution to thrush.
Severe or refractory inflammation with poorly controlled diabetes or major immunosuppression requires culture, species identification and specialist-directed management.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
Microscopy during symptomsFirst step
Why
Link a current inflammatory episode to budding yeast or pseudohyphae before treatment obscures the finding.
Interpretation and limitations
Compatible symptoms plus yeast forms support VVC. A negative preparation is not completely sensitive, so recurrent or persistent disease may still require culture.
02
Fungal culture with species identification
Why
Confirm recurrent or complicated VVC and distinguish C. albicans from organisms less likely to respond to standard fluconazole.
Interpretation and limitations
Interpret growth alongside symptoms, signs and pH. An asymptomatic positive result represents colonisation and does not justify antifungal treatment.
03
Susceptibility assessment
Why
Guide specialist care when adherent treatment fails and culture repeatedly supports ongoing Candida disease.
Interpretation and limitations
An in-vitro result is only one part of the decision; exclude ongoing irritants, an incorrect original diagnosis and non-albicans colonisation before escalating therapy.
04
Vaginal pH and differential testing
Why
Identify a pattern that does not fit VVC and direct tests for BV, trichomoniasis or cervical STI.
Interpretation and limitations
A pH of 4.5 or below is compatible with VVC, while a value above 4.5 points toward BV or trichomoniasis; blood, semen and sampling conditions can affect the result.
05
Pregnancy and targeted host assessment
Why
Choose a safe route of treatment and investigate a plausible modifier of severe or repeated disease.
Interpretation and limitations
Check pregnancy before oral therapy. Test for diabetes or immune compromise according to clinical evidence rather than applying a broad screen to every isolated episode.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

Bacterial vaginosis

Thin homogeneous discharge, fishy odour, clue cells and pH above 4.5 with little vulval inflammation favour vaginal dysbiosis over VVC.

Trichomoniasis

Raised pH, malodorous discharge and genital inflammation can overlap with both VVC and BV, but organism testing changes partner treatment and follow-up.

Irritant or allergic dermatitis

Washes, wipes, pads and repeated topical medicines produce burning and erythema without fungal evidence and may worsen with each empiric course.

Vulval dermatosis or vulvodynia

Persistent itch, architectural change, plaques, erosions or pain out of proportion to visible findings requires a careful skin and pain assessment rather than antifungal escalation.

Herpes or cervical infection

Ulcers, vesicles, contact bleeding, mucopurulent cervical discharge or pelvic tenderness directs lesion or STI testing because VVC therapy will not address the cause.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

01ACUTETreat a supported acute episodeFirst stepA stable adult has a first or occasional episode with a compatible inflammatory pattern.

1Ask about itch, soreness, external dysuria, odour, pelvic symptoms, bleeding, pregnancy possibility, recent antibiotics, diabetes risk and products already applied.
2Examine and obtain microscopy when symptoms are severe, atypical, persistent or diagnostically uncertain; do not let discharge colour substitute for syndrome recognition.
3For a suitable non-pregnant adult, select a topical imidazole or oral fluconazole after checking pregnancy, interactions and patient preference.
4Explain that symptoms should improve after treatment and arrange reassessment, rather than automatic repeat prescribing, if they do not.

02RECURRENTConfirm recurrence before suppressionThe patient reports at least four episodes in a year, rapid relapse, or repeated treatment with incomplete benefit.

1During symptoms, obtain microscopy and fungal culture before another dose where practical, recording which episodes meet the microbiological definition.
2Request species identification and specialist susceptibility advice for supported refractory disease, while reviewing adherence and all recent antifungal exposure.
3Look again for dermatitis, vulval dermatosis, vulvodynia, herpes, trichomoniasis or a cervical cause and assess diabetes, immune compromise, antibiotics and irritants when clinically indicated.
4For confirmed recurrent C. albicans VVC, agree an induction and six-month maintenance plan, then reassess after treatment stops rather than assuming lifelong suppression.

03PREGNANCYUse the pregnancy pathwayPregnancy is confirmed or reasonably possible in a patient with supported symptomatic VVC.

1Use a recommended intravaginal topical imidazole course, generally up to seven nights, and avoid oral azoles during pregnancy, pregnancy risk and breastfeeding.
2Give careful product instructions and avoid forceful applicator use during pregnancy.
3EscalationReview persistent symptoms with examination and microscopy or culture rather than shortening, repeating or escalating treatment empirically.
4EscalationEscalate pain, bleeding, collapse, fever or abdominal findings through the relevant pregnancy or acute pelvic pathway because VVC does not account for them.

Key medicines and prescribing safety2 treatments · regimens, roles and cautions

Treats uncomplicated Candida locally and provides the appropriate route when systemic azole exposure should be avoided.

Clotrimazole vaginal pessary

Insert 500 mg intravaginally once for uncomplicated vulvovaginal candidiasis; use a longer topical azole course in pregnancy.

Follow the formulation instructions, avoid forceful applicator use in pregnancy and examine persistent symptoms before another empiric course.

Provides a convenient oral option for a confirmed or strongly supported uncomplicated episode in a suitable non-pregnant adult.

Fluconazole

Take 150 mg orally as a single dose for suitable uncomplicated vulvovaginal candidiasis.

Avoid in pregnancy; review hepatic disease, QT risk and interacting medicines, and confirm recurrent disease before prolonged off-label suppression.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

Recurrent symptom burden

Repeated itch, soreness and fissuring can disrupt sleep, work and sexual activity even though infection remains superficial.

Diagnostic entrenchment

A repeated “thrush” label may delay recognition of dermatosis, neuropathic pain, STI or irritant injury when later episodes are never re-examined.

Treatment-related harm

Unnecessary systemic or topical therapy creates adverse effects, interactions and further irritation without benefiting colonisation or a non-fungal disorder.

Psychosexual effects

Pain, fear of recurrence and misplaced concern about sexual transmission can reduce intimacy; explanation should separate endogenous overgrowth from partner blame.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

Use clinical improvement rather than a repeat culture as the usual outcome after an uncomplicated episode.
If itch, pain or discharge persists, re-examine and obtain appropriate microbiology before issuing another remote antifungal prescription.
For recurrent VVC, maintain an episode record showing symptoms, microscopy, culture species, treatment exposure and response so the diagnostic criteria remain visible.
During maintenance, review adverse effects, interactions, adherence and breakthrough symptoms, then reassess the need for treatment after the six-month course ends.
Recheck pregnancy possibility whenever systemic azole use is contemplated and investigate any inadvertent exposure through the appropriate medicines-in-pregnancy route.
A change toward odour with raised pH, ulcers, bleeding, pelvic pain or visible architectural skin change should trigger the relevant alternative pathway.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

Inflammation defines the illness

Candida detection only becomes VVC when it fits vulvovaginal symptoms and signs; colonisation in a well patient requires no treatment.

Discharge is optional

Substantial itch, erythema and fissuring may occur with little discharge, while a thick discharge alone is not proof of Candida disease.

The pH result is a fork

Preserved acidity supports VVC, whereas raised pH should redirect attention to BV, trichomoniasis, blood, semen or mixed disease.

Recurrent is a verified category

Counting self-diagnosed episodes without microscopy or culture can turn several different vulval conditions into one false recurrent-thrush history.

Non-albicans needs correlation

A non-albicans culture may explain poor response or may represent colonisation; specialist decisions should integrate species, susceptibility and the examination.

Partner treatment is not routine

VVC is generally endogenous overgrowth, so treating an asymptomatic partner does not replace confirming and managing the patient’s own syndrome.

11Common pitfallsFrequent interpretation and management errors.

01
Treating Candida reported from an asymptomatic swab as active infection.
02
Diagnosing VVC solely from white discharge without asking about inflammation, odour, pH or alternative causes.
03
Calling repeated symptoms recurrent VVC before the required symptomatic and microbiological episodes are documented.
04
Using oral fluconazole in pregnancy when topical imidazole treatment is the recommended route.
05
Assuming every treatment failure is resistant yeast instead of checking use, culture species, irritants and the original diagnosis.
06
Allowing BV management to dominate a Candida chapter; here it is used to explain the raised-pH, low-inflammation differential.
07
Missing pelvic pain, bleeding, ulceration or persistent skin change because a common vaginal organism was detected.

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