What could be the cause of a white spot on my genitals and how can it be treated?

White Spots on Genitals: Diagnosis and Management

The most likely diagnosis for white spots on the genitals is lichen sclerosus, which requires prompt treatment with potent topical corticosteroids to prevent irreversible scarring and sexual dysfunction. 1

Primary Differential Diagnosis

White spots on genital skin most commonly represent one of three conditions:

• Lichen sclerosus: Presents as porcelain-white papules and plaques, often with follicular delling, affecting the vulva in women (interlabial sulci, labia minora, clitoral hood) or penis in men (balanitis xerotica obliterans). 1 This is an autoimmune inflammatory dermatosis that causes progressive scarring if untreated. 1

• Genital warts (HPV): Appear as white, flesh-colored, or pigmented papules that may have a cauliflower-like, flat, papular, or keratotic appearance. 2, 3 Caused by HPV types 6 and 11 in approximately 90% of cases. 2, 4

• Normal anatomical variants: Include Fordyce spots (ectopic sebaceous glands), pearly penile papules, or areas of hypopigmentation. 5, 6

Critical Distinguishing Features

Lichen Sclerosus Characteristics:

• Appearance: Porcelain-white color with smooth, atrophic surface; may show ecchymosis (bruising) or hyperkeratosis. 1
• Symptoms: Intense itching (especially nocturnal), pain from fissures or erosions, dyspareunia. 1 May be completely asymptomatic. 1
• Distribution: Classic "figure-of-eight" pattern around vulva and anus in women; glans and foreskin in men. 1
• Scarring: Progressive architectural changes including loss of labia minora, clitoral hood sealing, introital stenosis. 1

Genital Warts Characteristics:

• Appearance: Raised, exophytic lesions with variable texture; may be single or multiple clustered lesions. 2, 3
• Symptoms: Often asymptomatic, but may cause pruritus, pain, or friability. 2
• Distribution: External genitalia, perineum, perianal area; can occur on cervix, vagina, urethra, or anus. 2

When to Biopsy

Biopsy is mandatory in the following situations: 1, 2

• Diagnosis uncertain after clinical examination
• Lesions unresponsive to standard therapy after 3-6 treatments
• Lesions worsening during treatment
• Immunocompromised patients
• Pigmented, indurated, fixed, or ulcerated lesions (to exclude malignancy)

Treatment Algorithm

If Lichen Sclerosus is Diagnosed:

First-line treatment: Ultra-potent topical corticosteroids (clobetasol propionate 0.05%) applied once daily. 1 This is the standard of care to prevent irreversible scarring and preserve sexual function. 1

If Genital Warts are Diagnosed:

Treatment goal: Remove symptomatic visible warts, not HPV eradication (which is impossible with current therapies). 1, 4

First-line options based on CDC guidelines: 1, 4

Patient-applied therapies:

• Podofilox 0.5%: Apply twice daily for 3 consecutive days, then 4 days off; repeat up to 4 cycles. 1, 4 Contraindicated in pregnancy. 4
• Imiquimod cream: Applied per product instructions; works better on moist surfaces. 1, 4 Contraindicated in pregnancy. 4

Provider-administered therapies:

• Cryotherapy with liquid nitrogen: Preferred first-line option with 63-88% efficacy and 21-39% recurrence rate. 4, 7 Apply every 1-2 weeks until clearance. 7
• Trichloroacetic acid (TCA) 80-90%: Apply only to warts until white "frosting" develops; neutralize excess with talc or sodium bicarbonate. 1, 4 Safe in pregnancy. 4, 7 Efficacy 81% with 36% recurrence. 7

Treatment modification: Change modality if no substantial improvement after 3 provider treatments or incomplete clearance after 6 treatments. 1, 4

Special Populations

Pregnancy:

• For lichen sclerosus: Continue topical corticosteroids with specialist consultation. 1
• For genital warts: Use only cryotherapy or TCA; avoid podofilox, podophyllin, and imiquimod. 4, 7

Immunocompromised patients:

• May have more extensive or treatment-resistant disease. 2
• Higher index of suspicion for malignancy; lower threshold for biopsy. 1, 2

Critical Pitfalls to Avoid

• Do not dismiss white lesions as "normal" without proper examination, as untreated lichen sclerosus causes irreversible scarring and 4-5% risk of squamous cell carcinoma. 1
• Do not use HPV DNA testing for routine diagnosis or management of genital warts. 1, 2
• Do not treat subclinical HPV infection (acetowhite changes without visible warts), as this is not recommended and ineffective. 1
• Do not promise HPV eradication to patients with genital warts; treatment removes visible lesions but does not eliminate the virus. 1, 4
• Do not confuse perianal warts (can occur without anal intercourse) with intra-anal warts (require specialist referral). 1, 7

Patient Counseling for Genital Warts

Essential points to communicate: 1, 4

• HPV types 6 and 11 are low-risk and do not cause cancer. 4, 7
• Recurrence is common (approximately 30%) regardless of treatment method due to viral reactivation, not partner reinfection. 2, 4, 7
• Partners are likely already infected subclinically even without visible warts. 1
• 20-30% of untreated warts resolve spontaneously within 3 months. 4, 7
• Treatment does not affect cervical cancer risk. 1, 4