Molluscum Contagiosum: Symptoms, Diagnosis & Treatment

Molluscum contagiosum is a viral infection that causes the appearance of small, skin-colored or red lumps on the skin that can itch or become swollen. They are most frequently seen in children, and can affect any part of the body, with the exception of the palms of the hands and soles of the feet. 

This infection can be transmitted by direct contact from those infected with molluscum contagiosum, or through water contaminated with the virus, such as in swimming pools, hot tubs or bathtubs.

Molluscum contagiosum normally resolves on its own, however, it is important to consult a dermatologist for the most appropriate treatment. The doctor can prescribe ointments, cryotherapy or laser to help eliminate the lumps on the skin and reduce the risk of transmission.

Common symptoms

The main symptom of molluscum contagiosum is the formation of lumps on the skin, which usually have the following characteristics:

• Firm and small lumps, with a diameter between 2 mm and 5 mm
• Darker point in the center
• Appear anywhere on the body, except on the palms of the hands and soles of the feet
• Lumps that are isolated or grouped, in the form of a line
• Pearly and skin-colored, but can be red and inflamed

Molluscum contagiosum transmitted through intimate contact can lead to lumps on the genitals, anus, belly or inner thighs. In children, the spots tend to appear more frequently on the face, torso, arms or legs. 

Symptoms of molluscum contagiosum usually appear between 2 weeks and 6 months after initial contact with the virus.

Confirming a diagnosis

A molluscum contagiosum diagnosis is confirmed by a dermatologist through a skin evaluation of the skin. The doctor will examine the lesions and characteristics such as their size, location, color and quantity, in addition to the patient's health history and family history.

Generally, no specific exam is necessary, but more difficult diagnoses can be confirmed or ruled out through other tests, like a dermoscopy, confocal microscopy or histopathology. This way, the doctor can determine whether molluscum contagiosu  or another skin condition is present, like syringoma , warts, skin cancer, cryptococcosis or histoplasmosis.

Possible causes

Molluscum contagiosum is caused by an infection with the poxvirus virus, which infects cells in the most superficial layer of the skin, called keratinocytes. This virus does not penetrate into the body or affecting internal organs.

When keratinocytes become infected, the poxvirus produces proteins that prevent the immune system from responding to the infection, which contributes to skin lesions persisting and taking months to improve spontaneously.

How it's transmitted

The molluscum contagiosum virus can be transmitted through:

• Direct skin-to-skin contact with a person infected with the virus
• Indirect contact with objects contaminated with the virus, such as towels, personal or bedding clothing, gym mats or toys
• Water contaminated with the virus, in swimming pools, bathtubs or saunas
• Sexual contact with a person infected with the virus

Furthermore, more molluscum contagiosum lesions can appear when from scratching existing lesions, which causes the virus to spread to other areas of the skin.

Treatment options

Treatment for molluscum contagiosum is not always necessary, as the skin lesions may resolve on their own (usually within 6 months to 2 years). However, the dermatologist can recommend different treatments to reduce the risk for transmission to other people or to improve the appearance of the lesions for cosmetic reasons.

The main treatments for molluscum contagiosum include:

1. Use of ointments

The use of ointments for molluscum contagiosum may be recommended by a dermatologist or pediatrician. These stimulate an inflammatory response to the lesions, to help speed-up recovery. 

The main ointments for molluscum contagiosum that may be prescribed by your doctor include:

• Podophyllotoxin
• Potassium hydroxide
• Salicylic acid, which can be combined with povidone-iodine
• Benzoyl peroxide
• Tretinoin
• Trichloroacetic acid

Ointments for molluscum contagiosum should be used only if prescribed, as some (like podophyllotoxin and tretinoin) are contraindicated for pregnant women, breastfeeding women or children.

2. Surgical removal

Surgical removal of molluscum contagiosum skin lesions can be performed by a doctor using different techniques, such as:

• Cryotherapy, in which liquid nitrogen is applied to the bumps to freeze them, leading to them falling off
• Curettage, in which the doctor removes the bumps with a tool similar to a scalpel;
• Laser, which is done by applying the laser to the lesion to destroy affected skin cells and reduce their size.

Surgical removal of molluscum contagiosum lesions is typically performed using local anesthesia, which may cause pain, irritation or scarring on the skin after the procedure.

3. Medications

Some oral medications can be prescribed by the doctor, such as cimetidine, which can be an alternative treatment to surgical removal. This is especially considered for children.

Care during treatment

Some measures are important during the treatment of molluscum contagiosum, to avoid the appearance of new lesions on the skin and infecting other people. Some considerations to keep in mind when treating molluscum contagiosum include:

• Wash your hands frequently with neutral soap, especially after touching the skin lesion
• Keep lumps clean, dry and covered with clothing or a bandage
• Avoid scratching or picking at the lumps on the skin
• Do not try to remove the blisters yourself or squeeze the liquid out of the lesions
• Apply a moisturizer to your skin, as recommended by your doctor, as dry skin can cause itching and end up spreading molluscum contagiosum to other parts of the body;
• Use 2 towels to dry yourself after bathing, one towel to dry the blisters on the skin and the other towel to dry the parts of the body that do not have skin lesions
• Avoid shaving the areas of the body that have bumps
• Avoid shaving if you have bumps on your face;
• Do not share personal objects, such as towels, clothes, hairbrush, soap or toys
• Avoid going to swimming pools or swimming
• Avoid sex if you have active bumps in the genital region, groin or inner thighs

In addition, physical activities that require sharing objects, such as helmets, gloves or balls, or that involve direct contact with people, such as judo, karate or jiu-jitsu, should be avoided, unless the affected areas are fully covered.