What is the diagnosis and treatment for a wax-like papule in childhood that expresses sebum without pain, pruritus, or erythema?

Diagnosis: Molluscum Contagiosum

The diagnosis is molluscum contagiosum, a benign viral skin infection that presents as waxy, skin-colored papules expressing a white, cheesy sebaceous material (molluscum bodies) without associated pain, pruritus, or erythema in its uncomplicated form. 1

Clinical Presentation

Molluscum contagiosum presents as discrete, flesh-colored to waxy papules measuring 2-5 mm in diameter with characteristic central umbilication 1, 2. The lesions:

• Are typically skin-colored, whitish, or have a shiny surface 2
• Express white, cheesy sebaceous material when compressed (molluscum bodies) 1
• Commonly affect the trunk, face, and extremities in children 1
• Are usually asymptomatic without pain, pruritus, or erythema in uncomplicated cases 1
• Affect 5-11% of children aged 0-16 years 1

The infection is caused by molluscum contagiosum virus (MCV), a poxvirus transmitted through direct skin-to-skin contact or fomites, with childhood infections often linked to swimming pool attendance 3, 4.

Diagnostic Confirmation

Diagnosis is primarily clinical based on the characteristic appearance of umbilicated papules 1, 2. Dermoscopy reveals yellowish-white polylobulated structures with peripheral telangiectasia 2. Histologic examination or PCR can be performed in complex or unclear cases, though this is rarely necessary 1.

Treatment Approach

The recommended management is observation with spontaneous resolution, as molluscum contagiosum typically resolves within 6-12 months without intervention, though complete resolution can take up to 4 years. 1

Conservative Management (First-Line)

• Expectant observation is the gold standard approach 1, 4
• Resolution occurs spontaneously in 6-12 months in most cases 1
• No treatment is required for asymptomatic lesions 1

Active Treatment Options (When Indicated)

Active treatment may be considered for:

• Cosmetically bothersome locations 1
• Patients with underlying atopic dermatitis (who are predisposed to severe, protracted disease) 4, 5
• Prevention of transmission to siblings 4, 5

Treatment modalities with similar efficacy include: 1

1. Cryotherapy with liquid nitrogen - commonly used but may cause postinflammatory hyperpigmentation or scarring 1, 5

2. 10% potassium hydroxide - topical application with efficacy similar to cryotherapy 1

3. Cantharidin - effective therapy with high parental satisfaction rates, though evidence is limited to open-label studies 1, 5

4. Curettage - physical removal method 3

Treatments NOT Recommended

• Imiquimod - not shown to be beneficial compared to placebo in randomized controlled trials 1

Return to Activities

For athletes and children in organized sports or swimming, guidelines recommend:

• Covering lesions to avoid skin-to-skin contact 1
• Not sharing towels and fomites 1
• Limiting exposure to swimming pools during active outbreaks 1

Important Caveats

Inflammatory reactions can complicate molluscum and mimic other conditions 2, 4:

• Perilesional eczema may develop around lesions 2
• Molluscum dermatitis can cause pruritus and inflammation 4
• Children with atopic dermatitis develop widespread lesions complicated by dermatitis 4

These inflammatory manifestations can make diagnosis difficult and lead to unnecessary treatments 2. When inflammation is present, the underlying molluscum infection should still be recognized as the primary diagnosis 2.