Overview

Molluscum contagiosum is a common, benign skin infection caused by a poxvirus known as the molluscum contagiosum virus (MCV). It results in the appearance of small, raised, flesh-colored bumps on the skin that may have a central dimple or indentation. Molluscum contagiosum primarily affects children, but it can also occur in adults, especially those with weakened immune systems or those who are sexually active. The condition is generally harmless, non-cancerous, and self-limiting, meaning it often resolves without treatment within several months to a year.

Causes

Molluscum contagiosum is caused by direct infection with the molluscum contagiosum virus (MCV), which belongs to the poxvirus family. The virus spreads through:

• Skin-to-skin contact: Direct contact with the skin of an infected person, common during play in children or sexual activity in adults.
• Contaminated objects: Sharing towels, clothing, toys, or sports equipment can facilitate transmission.
• Self-inoculation: Scratching or touching the lesions and then touching other areas of the body can spread the infection.
• Weakened immunity: People with weakened immune systems, such as those with HIV/AIDS, are more susceptible to widespread lesions.

Symptoms

The primary symptom of molluscum contagiosum is the presence of characteristic skin lesions, which include:

• Small, round bumps: Typically flesh-colored, white, or pink, measuring 2 to 5 millimeters in diameter.
• Central dimple: Most lesions have a central indentation or umbilication.
• Shiny or smooth surface: Lesions are often dome-shaped with a waxy or shiny appearance.
• Number of lesions: Individuals may have a few lesions or clusters ranging from 10 to 20; in immunocompromised individuals, hundreds may appear.
• Itching or redness: The lesions may itch or become inflamed, especially if scratched.
• Common locations: Children commonly develop lesions on the face, neck, arms, and trunk, while adults often develop them on the genital area, inner thighs, and lower abdomen.

Diagnosis

Diagnosis of molluscum contagiosum is usually based on the clinical appearance of the lesions:

• Physical examination: A healthcare provider can typically identify molluscum by examining the distinctive bumps.
• Dermatoscope: In some cases, a dermatoscope (a magnifying device) is used to better visualize the central dimple.
• Skin biopsy: Rarely, if the diagnosis is unclear, a small skin biopsy may be performed for microscopic examination.
• No routine blood tests: Blood tests are not necessary unless evaluating underlying immune system concerns.

Treatment

In most cases, molluscum contagiosum resolves without treatment within 6 to 12 months. However, treatment may be recommended for cosmetic reasons, to prevent spread, or if lesions are bothersome:

• Observation: Many doctors recommend watchful waiting since the infection is self-limiting.
• Physical removal: Cryotherapy (freezing), curettage (scraping), or laser therapy can remove lesions quickly.
• Topical treatments: Prescription creams such as imiquimod, tretinoin, or cantharidin may help eliminate lesions over time.
• Oral medications: Rarely used, but in severe or widespread cases, immune-modulating drugs may be considered.
• Good hygiene: Avoiding scratching, covering lesions, and not sharing personal items can prevent spreading.

Prognosis

The prognosis for molluscum contagiosum is excellent:

• Self-resolving: Most cases clear up without treatment within 6 to 12 months, though some may take up to 18 months.
• Minimal scarring: Lesions generally heal without scarring unless scratched or infected.
• Low risk of complications: Occasionally, lesions may become red or infected, but serious complications are rare.
• Recurrence possible: Reinfection can occur, but long-term immunity develops over time.
• More severe in immunocompromised patients: People with weakened immune systems may have more persistent or widespread lesions requiring medical management.

With proper care and hygiene, molluscum contagiosum is a manageable condition with an excellent outcome in most individuals.