Molluscum contagiosum !

Molluscum contagiosum is a common viral skin infection causing small pearly bumps with a central dimple. It is frequent in children and usually clears alone.

Updated 2026-11-01

Structures involved

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Microorganisms that cause it

Molluscum contagiosum virus

Why it happens

What it is

A benign infection of the epidermis caused by the molluscum contagiosum virus, a poxvirus. It produces small, firm, dome-shaped, skin-coloured or pearly papules with a central umbilication. It affects mainly children; in adults it is often sexually transmitted, and extensive or giant lesions suggest immunosuppression.

Who gets it

Very common worldwide, especially in children aged 1–10 years, in warm humid climates and in crowded settings. In adults it appears on the genitals as a sexually transmitted infection, and in people with advanced HIV it can be widespread on the face. It is frequently seen in paediatric and dermatology clinics in Colombia.

Causes

Molluscum contagiosum virus (MCV), a DNA poxvirus that infects only humans
Spread by direct skin-to-skin contact, sexual contact and contaminated objects (towels, toys, sponges)
Autoinoculation by scratching or shaving spreads lesions on the same person

Risk factors

Childhood, attending day care or school
Atopic dermatitis (broken skin barrier and scratching)
Swimming pools, shared towels and contact sports
Sexual activity (genital lesions in adults)
Immunosuppression, especially HIV with low CD4 counts, transplant or immunosuppressive drugs

Pathophysiology

The virus infects keratinocytes and replicates in their cytoplasm, forming large eosinophilic inclusion bodies (molluscum or Henderson-Patterson bodies). Infected cells proliferate into a lobulated papule that opens at the centre, which explains the umbilication and the cheesy core. Viral proteins block local inflammation, so lesions persist until the immune system recognises them; redness around a lesion often signals the start of clearance.

Symptoms and signs

Small (2–5 mm), firm, smooth, dome-shaped, pearly or skin-coloured papules
Central dimple (umbilication) that may release a white, waxy material
In children: trunk, armpits, face, arms and folds; often grouped or in lines from scratching
In adults: lower abdomen, pubic area, inner thighs and genitals
Usually painless; itch or eczema around the lesions (molluscum dermatitis)
Redness and swelling of a lesion when it begins to resolve

Diagnosis

Clinical: Clinical diagnosis from the pearly umbilicated papules. Dermoscopy shows a central white-yellow structure with a crown of vessels at the edge.
Tests: If in doubt, curetted material or biopsy shows molluscum bodies on microscopy. Adults with genital lesions should be offered HIV, syphilis and other STI testing; HIV testing is advised in adults with extensive facial lesions.
Imaging: Not needed.

Differential diagnosis

Viral warts (rough surface, no central dimple)
Varicella or herpes simplex vesicles (fluid-filled, painful, acute)
Basal cell carcinoma (pearly papule in older adults)
In advanced HIV: disseminated cryptococcosis, histoplasmosis or talaromycosis that mimic molluscum
Milia, folliculitis and sebaceous hyperplasia

Goal of treatment

Allow spontaneous clearance when lesions are few, reduce spread to other sites and contacts, treat genital or troublesome lesions, and identify underlying immunosuppression.

Treatment

Conservative: Watchful waiting is reasonable in healthy children, because lesions clear by themselves; treat the surrounding eczema.
Procedure: Physical removal by curettage or cryotherapy with liquid nitrogen; cantharidin applied in the clinic; these can hurt and may scar.
Medical: Topical agents such as potassium hydroxide or podophyllotoxin in selected patients; in people with HIV, antiretroviral therapy that restores immunity is the most effective treatment.
Lifestyle: Do not scratch or squeeze lesions, cover them, avoid sharing towels, sponges and clothes; avoid shaving affected areas; condom use and abstaining while genital lesions are present.

Complications

Spread of lesions through scratching (autoinoculation)
Molluscum dermatitis around lesions
Secondary bacterial infection
Chronic follicular conjunctivitis from eyelid lesions
Small pitted scars after inflammation or procedures

Prognosis

In immunocompetent people each lesion lasts weeks to months and the infection usually clears without treatment in 6–12 months, sometimes up to several years. In advanced immunosuppression lesions can be extensive and persistent until immunity improves.

Prevention

Avoid touching other people's lesions and sharing towels, sponges or clothing
Cover lesions during swimming and contact sports
Hand washing after touching lesions
Safer sex practices

Test yourself

Think of the answer, then tap the question to see it.

Which virus family causes molluscum contagiosum?

Poxvirus (molluscum contagiosum virus).

What is the typical lesion?

A small, firm, pearly, dome-shaped papule with a central umbilication.

What do numerous large facial molluscum lesions in an adult suggest?

Immunosuppression, typically advanced HIV infection; HIV testing is indicated.

What is the histological hallmark?

Large eosinophilic intracytoplasmic inclusion bodies (molluscum or Henderson-Patterson bodies).

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Educational information, not medical advice. For any symptom, see a health professional.

Sources: Molluscum contagiosum (MedlinePlus, US National Library of Medicine, 2026); About Molluscum Contagiosum (Centers for Disease Control and Prevention (CDC), 2026).

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