How should I manage a pruritic penile papule?

Management of Pruritic Penile Papule

The most important first step is to determine whether this is an infectious, inflammatory, or neoplastic lesion through focused history and physical examination, as treatment differs dramatically between these etiologies.

Diagnostic Approach

Key Historical Features to Elicit

• Sexual history: Recent new partners, condom use, partner symptoms (suggests infectious etiology like herpes, HPV, or candidiasis) 1, 2
• Onset and duration: Acute onset with vesicles suggests herpes; chronic white patches suggest lichen sclerosus 3, 4, 2
• Associated symptoms: Burning, pain, discharge, urinary symptoms, or systemic symptoms 1, 2
• Prior episodes: Recurrent lesions in same location suggest herpes or fixed drug eruption 2, 5
• Medication history: Recent antibiotics (candidiasis), new topical products (contact dermatitis), or systemic medications (fixed drug reaction) 1, 6

Critical Physical Examination Findings

• Lesion morphology: Vesicles/ulcers (herpes), white atrophic patches (lichen sclerosus), red moist plaques on glans (erythroplasia of Queyrat), papillomatous growths (genital warts), or red scaly plaques (psoriasis) 1, 2, 7
• Distribution: Glans only, prepuce involvement, shaft, or urethral meatus involvement 1, 4, 2
• Examine entire skin surface: Psoriasis and lichen planus often have extragenital manifestations 2, 6, 5
• Palpate inguinal lymph nodes: Lymphadenopathy suggests infectious or malignant process 1, 2

Treatment Algorithm by Etiology

If Vesicular/Ulcerative Lesions (Suspect Herpes)

• First episode: Valacyclovir 1000 mg PO twice daily for 7-10 days (most effective when initiated within 72 hours of symptom onset) 8
• Recurrent episodes: Valacyclovir 500 mg PO twice daily for 3 days (most effective when initiated within 24 hours) 8
• Suppressive therapy: Valacyclovir 500-1000 mg PO daily for chronic suppression 8

If Papillomatous/Warty Lesions (Suspect HPV)

Patient-applied options (preferred for accessible lesions <10 cm² total area):

• Imiquimod 5% cream applied three times weekly at bedtime for up to 16 weeks, wash off after 6-10 hours 1
• Podofilox 0.5% solution/gel applied twice daily for 3 days, then 4 days off, repeat up to 4 cycles 1

Provider-administered options (for larger or refractory lesions):

• Cryotherapy with liquid nitrogen every 1-2 weeks 1
• Trichloroacetic acid 80-90% applied directly to warts until white "frosting" develops 1

Critical caveat: Change treatment modality if no substantial improvement after 3 provider treatments or 6 total treatments 1

If White Atrophic Patches with Pruritus (Suspect Lichen Sclerosus)

• First-line: Clobetasol propionate 0.05% ointment applied once daily to affected areas for 1-3 months 3, 4
• Expected outcome: 60% achieve complete symptom resolution (hyperkeratosis, fissuring, erosions resolve; residual pallor/scarring may persist) 3
• Maintenance: If symptoms recur when reducing frequency, increase application until resolution, then taper; most require 30-60g annually 3
• Refer for circumcision if no response after 3 months of adequate topical steroid therapy 3, 4

Critical warning: Lichen sclerosus carries ~5% risk of progression to squamous cell carcinoma; always send excised tissue for histology if circumcision performed 3

If Red Scaly Plaques (Suspect Candidal Balanitis)

• Topical antifungal: Clotrimazole 1% cream applied twice daily for 7-14 days 1, 9
• Alternative: Miconazole 2% cream applied twice daily for 7-14 days 1, 9
• Consider oral therapy: Fluconazole 150 mg single dose for widespread or refractory cases 1
• Treat sexual partner if recurrent infections occur 1

Common pitfall: Male partners of women with recurrent vulvovaginal candidiasis may benefit from treatment even if asymptomatic 1

If Red Scaly Plaques Without Fungal Features (Suspect Psoriasis/Eczema)

• Medium-potency topical steroid: Triamcinolone 0.1% ointment applied twice daily for 2-4 weeks 1, 2
• Note: Typical psoriatic scale is often absent on genital skin due to moisture and maceration 2, 6

When to Biopsy

Immediate biopsy is mandatory for:

• Any non-healing ulcer or lesion persisting >4 weeks despite appropriate treatment 1, 7
• Red, velvety plaques on glans (cannot exclude erythroplasia of Queyrat or Bowen's disease clinically) 1, 2
• White plaques with induration or irregular borders 1, 7
• Any lesion with atypical features or concerning for malignancy 1, 7

When to Refer to Dermatology/Urology

Urgent referral (<2 weeks):

• Suspected malignancy or premalignant lesion 1, 4
• Lichen sclerosus not responding to ultrapotent topical steroid after 3 months 4
• Phimosis or urethral stricture complicating lichen sclerosus 3, 4

Routine referral:

• Diagnostic uncertainty after initial evaluation 1, 2
• Recurrent infections despite appropriate treatment 1, 2
• Extensive disease requiring systemic therapy 1, 9

Critical Pitfalls to Avoid

• Do not assume all penile lesions are sexually transmitted: Psoriasis, eczema, and lichen sclerosus are common non-infectious causes 2, 6, 5
• Do not delay biopsy of persistent lesions: Squamous cell carcinoma and premalignant lesions may appear clinically benign 1, 2, 7
• Do not use topical calcineurin inhibitors for lichen sclerosus: Increased neoplasia risk in a disease with premalignant potential 4
• Do not treat genital warts without confirming diagnosis: Other papular lesions (pearly penile papules, seborrheic keratoses) are normal variants requiring no treatment 1, 7
• Do not prescribe antifungals empirically for all red penile lesions: Many inflammatory dermatoses mimic candidiasis but require steroid therapy 2, 6, 9