DR8.5 | Molluscum Contagiosum Recognition — Summary & Reflection

KEY TAKEAWAYS

Molluscum contagiosum is caused by molluscum contagiosum virus, a poxvirus that replicates in the keratinocyte cytoplasm, producing the histological hallmark of Henderson-Paterson (molluscum) bodies and encoding immune-evasion proteins that let lesions persist. Its diagnostic signature is the pearly, dome-shaped papule with a central umbilication (dell), and it has no ganglion latency, spreading by contact, fomites, sexual contact and autoinoculation. The same lesion carries different meaning across three contexts: benign and self-limiting in children; a sexually transmitted infection (genital/inner-thigh) in adults; and extensive, giant (greater than 1 cm), atypical and facial in the immunocompromised, where it signals low immunity and should prompt HIV testing. The key differential is the rough, black-dotted wart (versus smooth, umbilicated molluscum), with milia and sebaceous cysts also considered, and cryptococcosis mimicking it in HIV. Management is context-led: watchful waiting for children, physical/topical treatment (cryotherapy, curettage, KOH, imiquimod) when wanted, STI counselling for adults, and — crucially in HIV — antiretroviral therapy to restore immunity.

REFLECT

Think of a patient you have seen with molluscum contagiosum, or imagine the next child brought in with a scatter of small bumps. At the time, could you have named the diagnosis from the central dimple alone, and would you have read the clinical context — reassuring a parent, screening an adult for other STIs, or testing for HIV in someone with extensive atypical lesions? Consider how you would explain to a parent that their child's molluscum will likely clear on its own and why painful treatment is often unnecessary, and how your approach would change entirely for an immunocompromised patient. Anchoring the umbilicated-papule signature and the three-context reading to a real patient is what turns this into a dependable clinical reflex.