Reproductive · Infectious Disease
The facts most likely to be tested
Vulvovaginal candidiasis typically presents with thick, white, curdy, cottage cheese-like discharge and intense vulvar pruritus.
The vaginal pH in patients with candidiasis remains normal (≤ 4.5), which helps distinguish it from bacterial vaginosis or trichomoniasis.
Microscopic examination of a saline wet mount or 10% KOH preparation reveals pseudohyphae or yeast buds.
The most common causative pathogen is Candida albicans, though non-albicans species like Candida glabrata should be suspected in recurrent or refractory cases.
First-line treatment for uncomplicated vulvovaginal candidiasis is a short course of topical azoles or a single dose of oral fluconazole.
Recurrent vulvovaginal candidiasis is defined as four or more episodes of symptomatic infection within one year and requires long-term maintenance antifungal therapy.
Risk factors for symptomatic infection include recent antibiotic use, uncontrolled diabetes mellitus, pregnancy, and immunosuppression.
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A 26-year-old female presents to the clinic complaining of severe vaginal itching and burning for the past 3 days. She recently completed a 7-day course of amoxicillin for sinusitis. On physical examination, the vulva is erythematous with excoriations, and the vaginal mucosa shows thick, white, clumpy discharge. A pH test of the vaginal fluid is 4.2. A 10% KOH preparation of the discharge is performed in the office.
What is the most likely microscopic finding on the KOH preparation?
Pseudohyphae
The patient's clinical presentation of pruritus, thick discharge, and normal pH following antibiotic use is classic for vulvovaginal candidiasis, which is confirmed by the presence of pseudohyphae on KOH prep.
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Etiology / Epidemiology
Caused by Candida albicans overgrowth. Key risks: antibiotic use, diabetes mellitus, and pregnancy.
Clinical Manifestations
Presents with curd-like discharge and intense vulvar pruritus. Erythema and excoriation are classic.
Diagnosis
Diagnosis via wet mount showing pseudohyphae or yeast buds. pH < 4.5 is diagnostic.
Treatment
First-line is fluconazole 150mg PO x 1 dose. Avoid oral azoles in pregnancy.
Prognosis
Highly responsive to therapy. Recurrent defined as ≥4 episodes/year.
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Epidemiology & Etiology
Most commonly caused by Candida albicans, a commensal organism. Risk factors include immunosuppression, high-estrogen states (pregnancy/OCPs), and recent broad-spectrum antibiotic therapy. It is not classified as a sexually transmitted infection.
Pertinent Anatomy
The vaginal environment is typically acidic, maintained by Lactobacillus species. Disruption of this flora allows fungal proliferation within the vaginal vault and vulvar tissues.
Pathophysiology
Glycogen content in vaginal epithelial cells promotes fungal growth. Antibiotics reduce protective Lactobacillus, raising pH and allowing yeast to transition to the invasive pseudohyphal form. This triggers an inflammatory response leading to classic symptoms.
Clinical Manifestations
Patients report intense vulvar pruritus, burning, and dyspareunia. Physical exam reveals cottage cheese discharge and vulvovaginal erythema. Red flags include fever or pelvic pain, which suggest pelvic inflammatory disease or other complications.
Diagnosis
The wet mount (saline microscopy) is the gold standard for identifying pseudohyphae or yeast buds. A KOH preparation may be used to dissolve epithelial cells for better visualization. The vaginal pH is < 4.5, distinguishing it from bacterial vaginosis or trichomoniasis.
Treatment
Uncomplicated cases are treated with fluconazole 150mg PO single dose or topical clotrimazole. Oral fluconazole is teratogenic; use topical azoles for pregnant patients. Recurrent cases require a longer induction and maintenance regimen with fluconazole weekly for 6 months.
Prognosis
Prognosis is excellent with appropriate antifungal therapy. Recurrent vulvovaginal candidiasis (≥4 episodes/year) requires evaluation for underlying diabetes mellitus or immune deficiency.
Differential Diagnosis
Bacterial Vaginosis: thin, gray discharge with fishy odor and pH > 4.5
Trichomoniasis: yellow-green, frothy discharge with strawberry cervix
Atrophic Vaginitis: thin, pale mucosa in postmenopausal patients
Contact Dermatitis: history of irritant exposure with localized rash
Chlamydia/Gonorrhea: often asymptomatic or associated with mucopurulent cervicitis