What are the differential diagnoses for vaginal itching with ICD-10 (International Classification of Diseases, 10th Revision) codes?

Differential Diagnoses for Vaginal Itching with ICD-10 Codes

The three most common infectious causes of vaginal itching are vulvovaginal candidiasis (20-25% of cases), bacterial vaginosis (40-50% of cases), and trichomoniasis (15-20% of cases), with noninfectious causes accounting for 5-10% of cases. 1

Primary Infectious Causes

Vulvovaginal Candidiasis (VVC)

• ICD-10 Code: B37.3 (Candidiasis of vulva and vagina)
• Vaginal itching is the most specific symptom of VVC and may be the only complaint in some cases. 2
• Other symptoms include vaginal soreness, swelling, burning, dyspareunia, dysuria, and thick white discharge resembling cottage cheese 2, 3
• Vaginal pH is typically ≤4.5 4
• Diagnosis confirmed by microscopy showing yeast or pseudohyphae, or by culture 5
• Accounts for 20-25% of vaginitis cases when a cause is identified 1

Bacterial Vaginosis (BV)

• ICD-10 Code: N76.0 (Acute vaginitis)
• Characterized by malodorous discharge with minimal irritation 4
• Vaginal pH >4.5 5, 4
• Presence of clue cells on microscopy and positive whiff test 5
• Most prevalent cause of vaginal discharge or malodor, accounting for 40-50% of cases 5, 1
• Up to 50% of women with BV may be asymptomatic 5

Trichomoniasis

• ICD-10 Code: A59.01 (Trichomonal vulvovaginitis)
• Presents with malodorous yellow-green discharge, dysuria, and vulvar irritation 4
• Vaginal pH >4.5 4
• Diagnosis by visualization of motile trichomonads on wet mount or nucleic acid amplification testing 4
• Accounts for 15-20% of vaginitis cases 1

Noninfectious Causes (5-10% of Cases)

Atrophic Vaginitis (Genitourinary Syndrome of Menopause)

• ICD-10 Code: N95.2 (Postmenopausal atrophic vaginitis)
• Common in postmenopausal women due to estrogen deficiency 6
• Presents with vaginal dryness, itching, and dyspareunia 1
• Treated with hormonal and nonhormonal therapies 1

Lichen Sclerosus

• ICD-10 Code: L90.0 (Lichen sclerosus et atrophicus)
• Second most common cause of vulvar pruritus after candidiasis 7
• Chronic dermatosis requiring high-potency topical glucocorticoids 7

Contact Dermatitis/Irritant Vaginitis

• ICD-10 Code: L24.9 (Irritant contact dermatitis, unspecified) or L23.9 (Allergic contact dermatitis, unspecified)
• Caused by mechanical, chemical, or allergic irritation 5
• Presence of external vulvar inflammation with minimal discharge 5
• Treatment directed at eliminating triggering factors 7

Vulvar Eczema

• ICD-10 Code: L30.9 (Dermatitis, unspecified)
• Common chronic dermatosis causing vulvar pruritus 7
• Requires restoration of epidermal barrier function and suppression of inflammation 8

Inflammatory Vaginitis

• ICD-10 Code: N76.0 (Acute vaginitis)
• May improve with topical clindamycin and steroid application 1

Preinvasive/Neoplastic Causes

Vulvar Intraepithelial Neoplasia (VIN)

• ICD-10 Code: N90.0 (Mild vulvar dysplasia) or N90.1 (Moderate vulvar dysplasia)
• Should be considered in refractory cases of vulvar pruritus 7
• Requires biopsy for diagnosis 7

Vulvar Malignancy

• ICD-10 Code: C51.9 (Malignant neoplasm of vulva, unspecified)
• Rare but important consideration in persistent cases 7

Diagnostic Algorithm

Laboratory confirmation is recommended before treatment, especially for first episodes. 2

Essential Diagnostic Steps:

• Vaginal pH testing to differentiate VVC (pH ≤4.5) from BV and trichomoniasis (pH >4.5) 4
• Wet mount microscopy with saline to identify trichomonads and clue cells 4
• KOH preparation to identify yeast or pseudohyphae 5, 4
• Whiff test (amine odor with KOH suggests BV) 5
• Culture remains the gold standard for VVC diagnosis when microscopy is negative 5

Common Pitfalls to Avoid

• Do not treat empirically without proper diagnosis - less than half of patients treated for VVC actually have the condition confirmed by objective testing 5, 4
• Symptoms alone cannot reliably distinguish between causes of vaginitis 9
• Mixed infections are common and may require combination therapy 4
• In refractory cases, always consider preinvasive lesions or dermatologic conditions requiring biopsy 7
• Approximately 10-20% of women normally harbor Candida species without symptoms, so treatment should be based on both symptoms and laboratory findings 2