Molluscum contagiosum appears as small, firm, dome-shaped bumps on the skin, typically 2 to 5 millimeters across (roughly the size of a pencil eraser or smaller). They’re flesh-colored or pearly white, and their hallmark feature is a tiny dimple or indentation right in the center of each bump. That central dip is the single most reliable visual clue that distinguishes molluscum from other skin conditions.
The Bumps Up Close
Each molluscum bump is smooth, round, and raised, with a waxy or slightly shiny surface. The color usually matches your skin tone, though some bumps lean more toward pink or pearly white. They feel firm to the touch, not soft or fluid-filled like a blister.
The defining feature is the central dimple, sometimes called an umbilication. It looks like someone gently pressed the tip of a pin into the top of the bump. Inside that tiny crater sits a plug of white, waxy material. If you were to squeeze or nick a bump (which isn’t recommended), that white core would come out rather than pus, which is one way clinicians distinguish molluscum from infections like folliculitis or staph abscesses.
Most people develop anywhere from a handful to a few dozen bumps. They tend to appear in clusters rather than as isolated spots, and new ones can crop up nearby as the virus spreads across the skin through scratching or friction. Bumps are usually painless, though the surrounding skin can become red, dry, or itchy, sometimes developing a patch of eczema around the lesion.
Where the Bumps Typically Show Up
In children, the head and neck are the most commonly affected areas (about 66% of cases), followed by the trunk (45%) and the arms (23%). Kids tend to pick up the virus through skin-to-skin contact during play or by sharing towels, so the bumps cluster wherever that contact happened.
In adults, the distribution is similar, with head, neck, and trunk being common, but genital involvement is more frequent (23% of adult cases compared to about 15% in children). Adults are also more likely to have bumps in multiple body areas at once. When molluscum appears in the genital region of an adult, it’s typically spread through sexual contact.
What Molluscum Can Be Confused With
Several common skin conditions look similar at first glance. Folliculitis produces small red or white bumps around hair follicles, but those are tender and contain pus. Bug bites are typically itchier, flatter, and lack the smooth dome shape. Warts have a rough, textured surface rather than the smooth, shiny look of molluscum. Staph infections, including MRSA, tend to cause the surrounding skin to peel or slough off, which molluscum does not.
The trick to spotting molluscum is always that central dimple. If you look closely (a magnifying glass helps) and see a small indentation at the top of each bump, that’s a strong indicator. Dermatologists can usually diagnose molluscum just by looking at the skin, without any testing. In rare ambiguous cases, a tiny scraping of the bump is examined under a microscope to confirm.
One pattern worth knowing: sometimes a child develops an unexplained patch of eczema on an arm, leg, or skin fold that they’ve never had before. Buried in the center of that eczema patch, there may be a molluscum bump causing the irritation. If you see a new, localized eczema flare, it’s worth checking for a small bump hiding within it.
When Bumps Look Unusual
In people with healthy immune systems, molluscum bumps stay small and resolve on their own over months (sometimes up to a year or longer). But in people with weakened immune systems, particularly those with advanced HIV or severe eczema, the bumps can behave very differently.
So-called “giant” molluscum lesions can grow to 1 to 2 centimeters or larger, big enough to resemble skin tumors or cysts. They may be more numerous, more widespread, and much slower to clear. In one documented case, a patient with undiagnosed HIV developed 14 pearly-white nodules ranging from 0.5 to nearly 2 centimeters across the buttocks. Large or unusually persistent molluscum in an adult can sometimes be the first visible sign of an underlying immune problem.
How It Changes Over Time
Molluscum bumps go through a predictable life cycle. They start as tiny, barely noticeable spots, then grow over several weeks into the characteristic dome shape with the central dimple. Before they resolve, bumps often become inflamed: redder, slightly swollen, and sometimes tender. This inflammation is actually a sign that your immune system has recognized the virus and is fighting it off. Within a few weeks of that inflammatory phase, the bump typically flattens and fades.
The frustrating part is that while some bumps are resolving, new ones can still appear nearby, especially if you’ve been scratching or the area has been irritated. This is because the waxy core of each bump contains virus particles, and breaking the skin spreads them to adjacent areas. The cycle of new bumps appearing while old ones heal is why molluscum can seem to drag on for many months, even though individual bumps don’t last that long.