Molluscum contagiosum: definition, causes, symptoms, diagnosis and treatment
Molluscum contagiosum is a viral skin infection that causes lesions of the skin and, more rarely, the mucous membranes. Molluscum contagiosum presents itself with skin lesions with a typical dome shape called papule with a hollow in the centre, called umbilication
Papules may occur in very variable numbers, ranging from a few to hundreds.
The infection can also occur in any area of the body except the palms of the hands and the soles of the feet.
Molluscum contagiosum affects both adults and children, although it occurs much more often in the latter.
What is molluscum contagiosum?
Molluscum contagiosum is an infectious disease that affects the skin and, rarely, the mucous membranes.
It is manifested by small, solid elevations of the skin that, unlike pustules, do not contain pus and are called papules.
The papules caused by a group of viruses belonging to the Poxviridae family are between 2 and 5 millimetres in diameter, have a smooth surface and are pink in colour.
This particular disorder is particularly contagious, as the lesions not only spread quickly and easily from one skin area to another, but also from person to person.
Molluscum contagiosum is usually transmitted through direct contact by touching an infected person or even through objects used by the same person: towels, bathrobes, sponges or hygienic equipment.
Early intervention with targeted treatments to combat this infection is of paramount importance; however, in some individuals, especially immunocompromised individuals such as AIDS patients, eradicating this disease may be more difficult.
For this reason, in these more severe cases, more invasive treatments such as surgery or cautery of the lesions can be used.
What are the symptoms?
All skin surfaces can be affected by molluscum contagiosum, with the exception of the soles of the feet and the palms of the hands.
As already mentioned, the main symptom of this disorder is the appearance of pink-coloured papules with a smooth surface, which are usually between 2 and 5 millimetres in diameter, but in immunocompromised patients can be up to 15 millimetres in diameter.
The infection generally appears on the face, trunk and limbs in children, while in adults the most affected areas are the pubic area, penis or vulva.
Although very noticeable, the lesions usually only cause an itching sensation and slight pain, the major discomfort being related to an aesthetic factor.
Diagnosis of molluscum contagiosum is generally simple
Contact your general practitioner or a dermatologist, who will be able to accurately identify the nature of the disorder based on direct observation of the lesions.
In cases where the diagnosis is uncertain, the lesion can be thoroughly examined by means of a skin biopsy, a minimally invasive test that allows the molluscs to be analysed under an electron microscope.
Although the pathology is benign, in some cases there is a need to investigate the infection further with a differential diagnosis, in order to rule out the possibility of a more serious pathology such as basal cell carcinoma, dermatitis herpetiformis, keratoacanthoma, herpes simplex and varicella.
Cures and treatments
The treatment of molluscum contagiosum aims at eliminating the skin blemishes caused by the infection and preventing its spread.
The most suitable treatment for this condition may vary from patient to patient depending on age, extent of the lesions and the affected area.
It is possible to intervene with surgical methods, applying irritants, administering medication, or sometimes a combination therapy can be adopted.
Since molluscum contagiosum can often run asymptomatically, the diagnosis of this disorder can often be delayed.
The high infectiousness of this disease, however, is a factor that should not be underestimated: precisely for this reason, in order to avoid infecting other people, recognising the infection immediately is of great importance.
Although it is a disease that usually tends to recede spontaneously, dermatologists recommend treating the molluscum anyway, as the healing time is much faster if one undergoes targeted therapy.
Generally, the infection regresses spontaneously in 1-2 years, but sometimes the time is longer, up to 2-3 years.
However, papules if large and inflamed can leave scars.
Given the mild symptoms, treatment of molluscum contagiosum is recommended mainly for aesthetic reasons and to prevent its transmission.
Numerous specific drugs for the cure and treatment of this infection are available in pharmacies.
As an alternative to drug therapies, there is also the possibility of removing the molluscs immediately by surgical treatment.
This solution, which is more invasive, is prescribed mainly in more severe cases or in patients already debilitated by other diseases, as the lesions may appear more severe than normal and regress with greater difficulty.
Surgery is also prescribed for patients with very large lesions or in particularly delicate areas of the body, such as when the affected area is near the orbital rim.
Applying certain drugs directly to lesions caused by molluscum contagiosum is a practice that significantly shortens healing time.
The most commonly used drugs for this purpose are salicylic acid, potassium hydrochloride, some antiviral drugs, tretinoin or retinoic acid.
One of the treatments that causes less pain, and which for this reason is used especially in younger patients, is the one that is based on the use of a topical irritant: cantharidin; this treatment gives very satisfactory results in a short time, however it can cause blistering.
For this reason, when administered on children, it is always a good idea to inform the parents of the possible side effects.
Also for the same reason, cantharidin is not applied if the papules are located on the face or around the eyes.
Treatment of the mollusc with this substance involves applying a small drop of cantharidin directly onto the lesion, taking special care not to touch the liquid, which could cause skin irritation from contact.
For this same reason, the areas treated with cantharidin should then be bandaged so as not to be rubbed.
After 6 hours cantharidin should be washed off with soap and water.
Alternatively, for the treatment and cure of molluscum contagiosum to be carried out at home, potassium hydroxide-based products can also be purchased in pharmacies: the treatment lasts about 15 days and has satisfactory results even in the case of relapses.
Further treatments employ drugs generally used to treat acne or antivirals applied directly to the lesions.
If the lesions occur in particularly aggressive forms that drugs are not always able to eradicate quickly, it is advisable to consult a specialist for specific medical intervention.
Treatment modalities are varied and include various operations.
It must be kept in mind, however, that the surgical removal of papules caused by molluscum contagiosum can leave indelible scars on the skin, which is why the patient must be warned of the risks that can result from such operations.
Moreover, even after finishing the course of treatment of the infection, it is possible that it may recur and manifest itself again.
In order to minimise the risk of reoccurrence, it is advisable to start treatment in the early phase of the infection, i.e. when the lesions are few and small.
If the papules are few, they can be excised with local anaesthesia using a curette, or a sharp spoon.
There are also other alternative treatments such as burning, the use of iodine disinfectants or certain acids that destroy the papules.
In addition there is cryotherapy or cold therapy, which uses the action of liquid nitrogen to burn the lesions and encourage them to fall off.
These treatments are very effective but must be carried out with caution because they can be very painful, especially if practised without anaesthetic, which is why they are generally only performed on adults.
Lastly, there is laser therapy or discolouration with specific chemical agents and removal using forceps, which gently squeeze the lesions to remove the core.
How to prevent molluscum contagiosum?
Being an easily transmissible infection, unfortunately, preventing molluscum contagiosum is not easy.
There are, however, some precautions that can limit the possibility of contagion, in particular
- avoid using wipes and towels used by others;
- take precautions in common areas frequented by many people such as saunas, swimming pools and gyms;
- limit contact with others if you are used to playing sports.
To reduce the risk of relapse, however, the best solution is to treat the molluscum contagiosum as soon as it shows its first symptoms, so as to prevent it both spreading to other parts of the body and infecting other people.