How can I differentiate between human papillomavirus (HPV) warts and molluscum contagiosum lesions and what are the appropriate treatment options for each?

Differentiating HPV Warts from Molluscum Contagiosum

HPV warts and molluscum contagiosum are distinguished by their central morphology: paring down a wart reveals pinpoint bleeding from exposed capillary loops, while molluscum lesions display a characteristic central umbilication without bleeding. 1

Clinical Differentiation

HPV Warts (Verruca)

• Paring test is diagnostic: Use a scalpel to pare down the lesion—warts will show pinpoint bleeding as capillary loops of elongated dermal papillae are exposed 2, 1
• Disrupted or absent skin lines across the lesion surface 1
• Hyperkeratotic papulonodules with rough surface texture 1
• Caused by HPV types 1,2,4,27, or 57 for common warts 2
• Can appear cauliflower-like, flat, papular, or keratotic depending on location 3
• Anogenital warts (condyloma acuminatum) are caused by HPV types 6 and 11 and may have papillary projections 4, 3

Molluscum Contagiosum

• Central umbilication is pathognomonic: Small (2-5mm), dome-shaped, skin-colored papules with a central dimple or dell 5, 6
• No bleeding on paring—instead, a white, cheesy core material can be expressed 6
• Smooth, pearly surface without hyperkeratosis 6
• Caused by molluscum contagiosum virus (MCV), not HPV 7
• Multiple lesions often present in clusters 8, 6
• May have surrounding erythema or eczematous reaction 8

Examination Technique

• Soak the lesion in warm water to soften tissue before examination 1
• Carefully pare down superficial layers with a scalpel blade 1
• Inspect closely for bleeding points (wart) versus central umbilication with white core (molluscum) 1, 6

Treatment Algorithms

For HPV Warts

First-line treatment is salicylic acid 15-40% topical preparations (Level 1+ evidence, Strength A recommendation). 1

Treatment Options by Location:

• Common warts (hands/feet):

  • Salicylic acid 15-40% daily application after paring 1
  • Cryotherapy with liquid nitrogen every 2 weeks for 3-4 months 1
  • Expectant management is acceptable—50% clear spontaneously within 1 year in children, two-thirds by 2 years 2, 1

• Anogenital warts:

  • Cryotherapy with liquid nitrogen OR trichloroacetic acid (TCA) 80-90% applied only to warts, then powder with talc or baking soda 4
  • Repeat weekly for up to 6 applications 4
  • Surgical removal if persistent after 6 applications 4
  • Contraindication: Podophyllin and podofilox are contraindicated in pregnancy 4

• Oral warts:

  • Cryotherapy with liquid nitrogen, electrodesiccation, or surgical removal 4
  • Surgical excision is standard for HPV-associated oral lesions due to dysplasia risk 9

• Anal warts:

  • Cryotherapy with liquid nitrogen OR TCA 80-90% 4
  • Surgical removal for rectal mucosa involvement—refer to expert 4

For Molluscum Contagiosum

Treatment is indicated only for symptomatic patients or to prevent transmission, as lesions spontaneously resolve in 6-12 months (up to 4 years). 8, 6

Treatment Options:

• Incision and curettage: Aggressive enough to cause bleeding—most definitive treatment 5
• Simple excision with or without cautery 5
• Cryotherapy with liquid nitrogen: May cause postinflammatory hyperpigmentation or scarring 8
• 10% potassium hydroxide: Similar efficacy to cryotherapy in children 8
• Cantharidin: Observational studies show effectiveness, though one small RCT showed non-significant improvement over placebo 8
• Imiquimod 5% cream: NOT recommended—randomized controlled trials showed no benefit over placebo 8, 10

Special Considerations:

• Treat nascent lesions to reduce viral load and allow host immune response to eliminate residual virus 5
• Conjunctivitis from eyelid lesions may require weeks to resolve after lesion elimination 5
• Large and multiple lesions with minimal inflammation in adults suggest immunocompromised state—consider HIV testing 5

Critical Management Pitfalls

For Warts:

• Never use destructive treatments on facial warts without extreme caution—high scarring risk 1
• Recognize that wart treatments do not eradicate HPV—recurrence is common as virus persists in surrounding normal tissue 4, 1
• Avoid overdebridement causing pain and tissue damage 1
• In pregnancy, avoid podophyllin and podofilox; use cryotherapy or TCA instead 4
• Immunocompromised patients (HIV, transplant) may not respond to standard therapy 4

For Molluscum:

• Do not treat asymptomatic lesions aggressively—spontaneous resolution is the norm 8, 6
• Avoid imiquimod—proven ineffective in RCTs despite case reports 8, 10
• Be aware that 8% of clinical diagnoses of molluscum are actually HPV warts—consider biopsy if atypical 7
• Cryotherapy may cause permanent hyperpigmentation, especially in darker skin types 8

Follow-Up Protocols

HPV Warts:

• After successful treatment, routine follow-up is not necessary 4
• Annual cytologic screening recommended for women with genital warts 4
• Presence of genital warts is NOT an indication for colposcopy 4
• Sex partner examination not necessary—most partners already subclinically infected 4

Molluscum Contagiosum:

• Follow-up not usually necessary unless conjunctivitis persists after lesion removal 5
• Refer to dermatology for multiple suspicious lesions or immunocompromised patients 5
• Athletes should be excluded from contact sports until all lesions are treated or fully resolved 8