Molluscum contagiosum typically takes 2 to 7 weeks to appear after exposure, though in some cases the incubation period can stretch to 6 months. This wide range means you may not remember the specific contact that caused the infection by the time bumps show up on your skin.
What the First Bumps Look Like
The earliest sign is one or a few small, raised, round bumps that are skin-colored, white, or pink. They’re firm to the touch and usually smaller than 6 millimeters, roughly the size of a pinhead to a pencil eraser. The hallmark feature is a small dimple or dent in the center of each bump, though this may not be obvious on very early or very small lesions.
The bumps are painless, though some people notice mild itchiness. They tend to appear in clusters rather than as isolated spots. In children, they commonly show up on the face, trunk, arms, and legs. In adults who acquired the virus through sexual contact, lesions are more likely to appear on the lower abdomen, inner thighs, and genital area.
Why the Incubation Period Varies So Much
Several factors influence how quickly bumps develop after exposure. The amount of virus that enters the skin, the site of contact, and your immune response all play a role. People with eczema or atopic dermatitis are at higher risk because their skin barrier is already compromised, which may allow the virus to establish itself more quickly.
The long possible incubation window, up to 6 months, is one reason molluscum spreads so easily. You can pass the virus to others or to new areas of your own body before you even realize you’re infected.
How New Bumps Keep Appearing
One of the most frustrating aspects of molluscum is that new bumps can continue to appear for weeks or months after the first ones show up. This happens through a process called autoinoculation: touching or scratching an existing bump transfers the virus to nearby or even distant skin. Children with eczema are especially prone to this because frequent scratching disrupts the skin barrier and spreads the virus efficiently.
Shaving over affected areas is another common way the virus spreads across the skin. Each newly inoculated site goes through its own incubation period, which is why it can feel like the infection keeps expanding even after you’ve identified it.
To slow this spread, avoid picking, scratching, or shaving over bumps. Covering lesions with bandages can help reduce the chance of spreading the virus to other parts of your body or to other people.
How Long the Infection Lasts Overall
Once bumps appear, they usually resolve on their own within 6 to 12 months without treatment. In some cases, the infection can persist for up to 4 years before fully clearing. Individual bumps go through a lifecycle: they grow slightly, plateau, and then become inflamed or red before disappearing. That inflammation near the end is actually a sign your immune system is fighting off the virus in that spot.
Many people choose to wait it out, especially with children, since the infection is harmless and resolves without scarring in most cases. Others opt for treatment to speed things up, reduce the number of bumps, or limit spread to other people.
Molluscum in People With Weakened Immune Systems
The timeline and severity can look very different in people with compromised immune function. Those with HIV, organ transplant recipients on immunosuppressive medications, and people undergoing chemotherapy or taking systemic steroids are all at elevated risk for more extensive infections.
In these individuals, lesions can grow larger (up to 1 centimeter), appear in unusual locations like across the face, and resist treatment. Importantly, there is no evidence that molluscum resolves spontaneously in people with HIV the way it does in people with healthy immune systems. For anyone with a weakened immune system, molluscum tends to be a more persistent and widespread problem that requires active management rather than watchful waiting.
Recognizing Molluscum vs. Other Skin Bumps
The central dimple is the key visual clue that separates molluscum from warts, pimples, or other skin bumps. If you look closely at a mature lesion, you’ll see a tiny indentation right at the top. This feature becomes more obvious as the bump grows. Early bumps can be easy to confuse with other conditions, but as they develop over a few weeks the characteristic shape becomes clearer.
If you’re unsure, a healthcare provider can usually diagnose molluscum just by looking at the bumps. No blood tests or biopsies are typically needed.