Pediatric Molluscum: An Update
Molluscum contagiosum virus (MCV) is a poxvirus that causes infection in humans that is limited to the cutis and subcutaneous levels of the skin. The virus is transmitted from close associates in settings such as pools, day care, and bathtubs. Pediatric molluscum is common in school-aged children and resolves spontaneously in healthy children. Widespread lesions, complicated by comorbid dermatitis, are expected in children with atopic dermatitis (AD); however, even children without AD can develop dermatitis or signs of inflammation or pruritus. Molluscum is the great mimicker in pediatric dermatology; the morphology of the lesions and overlying rash can make molluscum look polymorphous and similar to other skin illnesses. This article addresses the issue of transmission, course of disease, comorbidities, and therapeutic options, including the gold standard—nonintervention. The decision to intervene is a joint decision among children, parents/guardians, and the practitioner. The first priority should be reduction of symptoms, followed by reduction of spread and then disease remission.
Practice Points
- Molluscum appears as pearly papules with a central dell (ie, umbilicated).
- Caused by a poxvirus, the disease is very contagious and transferred via skin-to-skin contact or fomites.
- One-third of children with molluscum will develop symptoms of local erythema, swelling, or pruritus.
- Diagnosis usually is clinical.
- Children are primarily managed through observation; however, cantharidin, cryotherapy, or curettage can be used for symptomatic or cosmetically concerning lesions.
Comorbidities
Molluscum lesions can occur in any child; however, the impaired immunologic status and skin barrier in patients with AD is ripe for the extensive spread of lesions that is associated with higher lesion count.36 Children with molluscum infection can experience new-onset dermatitis or triggering of AD flares, especially on the extremities, such as the antecubital and popliteal regions.7 A study of children with MCV infection demonstrated that treatment of active dermatitis reduced spread. The authors mentioned autoinoculation as the mechanism; however, these data also suggest supporting barrier state as a factor in disease spread.36 Superinfection can occur prior to6 or after therapy for lesions,37 but it is unclear if this relates to the underlying atopic diathesis. Children with molluscum have been described to have warts, psoriasis, family history of atopy, diabetes mellitus, and pityriasis alba,7 while immunosuppression of any kind is associated with molluscum and high lesion count or prolonged disease in childhood.1,2
Quality of Life
Children with molluscum who have higher lesion counts appear to be at risk for severe effects on their quality of life. Approximately 10% of children with MCV infection have been documented to have severe impairments on quality of life.39 In my practice, quality of life in children with MCV appears to be affected by many factors (Table 2).7,18,39
Treatments
Proper Skin Care and Treatment of AD
Therapy for AD and/or pruritus appears to limit lesion number in children with MCV and rashes or itch.7,36 I recommend barrier repair agents, including emollients and syndet bar cleansers, to prevent small breaks in the skin that occur with xerosis and AD and that increase itch and risk of spread. Therapy for AD and molluscum dermatitis is similar and overlapping. There is always a concern about the spread of MCV when using topical calcineurin inhibitors. I, therefore, focus the dermatitis therapeutics on topical corticosteroid–based care.6,40
Prevention of Spread
Prevention of spread begins with hygiene interventions. Cobathing is common in children with MCV and should be held off when possible. It is important for the child with MCV to avoid sharing bath towels and equipment23 and having bare skin come in contact with mats in sports. I request that children with MCV wear bathing suits that cover the areas affected.
Reassurance
The most important therapy is reassurance.41 Many parents/guardians are truly unaware that the MCV infection can last for more than a year and therefore worry over normal disease course. When counseled as to the benign course of illness and given instructions on proper skin care, the parent/guardian of a child with MCV will often opt against therapy of uncomplicated cases. On the other hand, there are medical reasons for treatment, and they support the need for intervention (Table 3). Seventy percent of lesions resolve in 1.5 years; however, of the residual infections, some may last as long as 4 years.16 It is not recommended to stop children from attending school because of MCV.
Interventional Therapy
Therapeutics of MCV include destructive therapies in office (ie, cantharidin, cryotherapy, curettage, trichloroacetic acid, and glycolic acid) and at-home therapies (ie, topical retinoids, nitric oxide releasers)(eTable).2,5,6,42-58 When there are many lesions or spread is noted, immunotherapies can be used, including topical imiquimod, oral cimetidine, and intralesional Candida antigen.2,4,7 Pulsed dye laser cuts off the lesion vascular supply, while cidofovir is directly antiviral both topically and systemically, the latter reserved for severe cases in immunosuppressed adults.59 Head-to-head studies of cantharidin, curettage, topical peeling agents, and imiquimod demonstrated better satisfaction and fewer office visits with topical anesthetic and curettage on the first visit. Side effects were greatest for salicylic acid and glycolic acid; therefore, these agents are less desirable.42
Conclusion
Molluscum is a cutaneous viral infection that is common in children and has associated morbidities, including AD, pruritus, poor quality of life in some cases, and risk of contagion. Addressing the disease includes understanding its natural history and explaining it to parents/guardians. Therapeutics can be offered in cases where need is demonstrated, such as with lesions that spread and cause discomfort. Choice of therapeutics depends on the practitioner’s experience, the child’s clinical appearance, availability of therapy, and review of options with the parents/guardians. When avoidance of intervention is desired, barrier enhancement and treatment of symptomatic dermatitis are still beneficial, as are household (eg, not sharing towels) and activity (eg, adhesive bandages over active lesions) interventions to reduce transmission.
