Is cryotherapy with liquid nitrogen (LN) effective for treating molluscum contagiosum?

Cryotherapy with Liquid Nitrogen for Molluscum Contagiosum

Cryotherapy with liquid nitrogen is an effective treatment option for molluscum contagiosum and is recommended for symptomatic patients or those with cosmetic concerns. 1

Treatment Rationale and Efficacy

Molluscum contagiosum is a common viral skin infection that presents as flesh-colored papules with central umbilication. While the condition is benign and often self-resolving, treatment may be indicated for several reasons:

• Lesions can persist for months to years (6-12 months typically, but up to 4 years in some cases)
• To prevent spread to other areas of the body through autoinoculation
• To prevent transmission to others
• For cosmetic concerns
• For symptomatic lesions (pain, itching, redness)
• In patients with underlying skin conditions such as eczema

Treatment Options

Current guidelines identify several effective treatment approaches for molluscum contagiosum:

1. Cryotherapy with liquid nitrogen - Physical destruction of lesions 1
2. Incision and curettage (aggressive enough to cause bleeding) 1
3. Simple excision 1
4. Excision and cautery 1
5. 10% potassium hydroxide solution 1, 2

Treatment Algorithm

When to treat:

• Symptomatic patients (pain, itching, redness)
• Cosmetic concerns
• Patients with underlying skin conditions like eczema
• Multiple lesions with risk of spread
• Lesions in areas prone to trauma or irritation

When to consider watchful waiting:

• Asymptomatic patients with few lesions
• Very young children who may not tolerate procedures well
• Patients/parents who prefer to avoid treatment

Cryotherapy Procedure and Considerations

Cryotherapy with liquid nitrogen is particularly effective because:

• It provides physical destruction of the viral lesions
• It can be performed in a single office visit (though multiple visits may be needed)
• It is considered one of the methods of choice for the majority of patients 3

Potential Side Effects:

• Postinflammatory hyperpigmentation (more common with cryotherapy than other treatments) 2
• Uncommon scarring 1
• Pain during application

Comparative Efficacy

A randomized clinical trial comparing 10% potassium hydroxide solution with cryotherapy found both treatments to be equally effective (93.3% complete response with cryotherapy vs. 86.6% with KOH after 4 weeks), with no statistically significant difference between the two treatments 2. However, cryotherapy was associated with more postinflammatory hyperpigmentation.

Special Considerations

• Multiple lesions: Identify and treat all lesions, including nascent ones, to reduce recurrence risk 1
• Immunocompromised patients: Adults with large and multiple molluscum lesions with relatively little conjunctival inflammation may indicate an immunocompromised state 1
• Follow-up: Not usually necessary unless conjunctivitis persists or lesions recur 1
• Referral: Consider dermatology referral for examination of other suspicious lesions 1

Emerging Treatments

While not yet FDA-approved, new treatments are in development, including standardized cantharidin preparation (VP-102) and topical nitric oxide-releasing product (SB206), which have shown promising results in phase III studies 4.

Clinical Pearls

• Reduction of viral load through treatment often allows the host immune response to eliminate residual virus 1
• In patients with ocular involvement, conjunctivitis may require weeks to resolve after elimination of the lesion 1
• Cryotherapy is more difficult to perform in young children due to pain during application 4
• Consider the patient's age, number and severity of lesions, location, and patient/parent preference when selecting treatment 3