A practical approach to molluscum contagiosum, Part 1: Definition and diagnosis

August 1, 2007

Chances are you've seen its handiwork. It's molluscum contagiosum, and while many 'peds' choose to let this infection run its course, there can be benefits to intervention.

Key Points

Molluscum lesions pose a conundrum for the pediatrician. Left alone, they disappear without treatment, but resolution can take several years and most patients (and parents) don't want to wait that long. Attacking the lesions directly can speed resolution, but destructive therapies are complex and can be hazardous. This primer shows you how widespread the infection is, teaches you how to recognize it, and provides tips on the best management strategies.

Background

Molluscum contagiosum virus, or MCV, is a highly contagious, widely disseminated poxvirus that infects the skin and mucous membranes of infants, toddlers, school-aged children, sexually active teenagers, and immunocompromised individuals. The infection spreads easily from child to child; more than 40% of infected children have an infected sibling and more than 30% report an infected friend.

Who gets molluscum?

Molluscum contagiosum affects as many as 20% of all children worldwide.1 A Dutch survey demonstrated a cumulative infection rate of 17% in children under the age of 15, and a seropositivity study conducted by Australian researchers showed antibodies to molluscum in 23% of the population.2,3 A trend towards an increasing incidence in the United States has also been observed, particularly for genital infection.1,4

The rate of infection peaks in the 2- to 11-year-old age group. Most studies show an equal distribution between the sexes, but a slight female predominance has been noted in children older than 8 years.5 Molluscum infections are more common in children with atopic dermatitis and are one of the minor criteria for diagnosis of that condition. In immunocompromised youngsters, infection can be extensive and severe, with the extent of the lesions possibly reflecting the level of immunocompetency.6-8 Indeed, patients with human immunodeficiency virus (HIV) infections have a tendency to develop more extensive lesions as their CD4 counts decrease.9,10

What does molluscum look like?