What are the infectious and non‑infectious causes of burning vaginal and suprapubic pain in a woman?

Causes of Burning Vaginal and Suprapubic Pain

Burning vaginal and suprapubic pain has both infectious and non-infectious etiologies that must be systematically evaluated, with infectious causes including bacterial vaginosis, vulvovaginal candidiasis, trichomoniasis, and pelvic inflammatory disease, while non-infectious causes encompass bladder pain syndrome/interstitial cystitis, atrophic vaginitis, vulvodynia, and irritant/inflammatory vaginitis.

Infectious Causes

Bacterial Vaginosis (BV)

• Presents with thin, homogenous vaginal discharge with characteristic fishy odor 1, 2
• Associated with normal vaginal pH (≤4.5) but disrupted vaginal flora
• Can cause vulvar burning and irritation 2
• Does not typically cause suprapubic pain unless ascending infection occurs
• Treatment: oral or intravaginal metronidazole or clindamycin 2

Vulvovaginal Candidiasis (VVC)

• Manifests with white, thick, curd-like discharge, intense pruritus, and vulvar erythema 1, 3
• Vulvar burning is a hallmark symptom, along with external dysuria and dyspareunia 1, 4
• Affects 75% of women at least once; 40-45% experience recurrent episodes 1, 3
• Diagnosis: visualization of yeast hyphae/budding yeast on microscopy or positive culture 2
• Treatment: topical or oral azole antifungals (80-90% cure rate) 1, 3

Trichomoniasis

• Presents with green/yellow frothy discharge, vaginal soreness, vulvar burning, and external dysuria 4, 2
• May cause suprapubic discomfort
• Diagnosis: motile flagellated protozoa on microscopy or NAAT 2
• Treatment: oral metronidazole 2g single dose or 500mg twice daily for 7 days 1, 3
• Partner treatment is mandatory to prevent reinfection 1

Pelvic Inflammatory Disease (PID)

• Causes suprapubic pain, often with fever, cervical motion tenderness 5, 6
• Includes endometritis, salpingitis, tubo-ovarian abscess 5, 7
• Accounts for 20% of pelvic pain cases in postmenopausal women 5
• Etiologies: Chlamydia trachomatis, Neisseria gonorrhoeae, BV-associated pathogens 6
• Can result from sexual activity or recent instrumentation/surgery 5

Non-Infectious Causes

Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC)

• Suprapubic pain, pressure, or discomfort related to bladder filling is the hallmark 8, 9
• Pain locations: bladder, urethra, vagina (burning sensation commonly reported) 8
• Pain typically improves with urination in 57-73% of patients 8
• Aggravated by: stress (61%), sexual intercourse (50%), acidic beverages (54%), coffee (51%), spicy foods (46%) 8
• Diagnosis of exclusion requiring minimum 6 weeks of symptoms 8
• Associated conditions: irritable bowel syndrome, vulvodynia, endometriosis, fibromyalgia 8

Atrophic Vaginitis

• Results from estrogen deficiency, particularly in postmenopausal women
• Presents with vaginal dryness, burning, dyspareunia 2, 10
• Physical exam reveals atrophic changes, thin vaginal epithelium 8
• Treatment: vaginal lubricants, moisturizers, topical estrogen 2

Vulvodynia

• Chronic vulvar pain without identifiable cause, affects up to 16% of women 11
• Described as burning, stinging, irritation, or rawness 11
• Can be generalized or localized (vestibulodynia, clitorodynia) 11
• Diagnosis of exclusion with multifactorial etiology 11
• Requires individualized treatment: vulvar care measures, psychological approaches, local treatments, oral medications 11

Desquamative Inflammatory Vaginitis (DIV)

• Presents with purulent discharge, vulvovaginal burning, dyspareunia 10
• Characterized by inflammatory process with polymorphonuclear neutrophils 10
• Less common but important differential for inflammatory vaginitis 10

Irritant/Contact Vaginitis

• Caused by soaps, detergents, douches, topical medications
• Presents with burning, irritation, clear or minimal discharge 2
• History of exposure to potential irritants is key 2

Diagnostic Approach

For vaginal burning:

1. Assess discharge characteristics (color, consistency, odor)
2. Check vaginal pH (normal <4.5 suggests candidiasis; >4.5 suggests BV or trichomoniasis)
3. Perform wet mount microscopy
4. Consider NAAT for trichomoniasis and STI screening if sexually active 2

For suprapubic pain:

1. Rule out urinary tract infection with urinalysis and culture 12
2. Assess relationship to bladder filling/emptying 8
3. Evaluate for pelvic inflammatory disease (fever, cervical motion tenderness) 5
4. Consider bladder pain syndrome if pain improves with voiding and other causes excluded 8, 9

Critical Pitfalls

• Do not treat asymptomatic candida colonization (10-20% of women harbor Candida normally) 1, 3
• Do not assume all vaginal burning is infectious—consider BPS/IC when suprapubic pain predominates and improves with voiding 8, 9
• Do not overlook partner treatment for trichomoniasis—reinfection rates are high without concurrent partner therapy 1, 3
• In postmenopausal women with acute pelvic pain, consider non-gynecologic causes (urinary, gastrointestinal, vascular) 5