The scabies, which had been discreet, has returned in force for a few years in schools and communities. This contagious skin condition is caused by a tiny parasitic, the mite Scabiei sarcoptes Var. hominis.
Although it does not transmit infectious diseases, its action on the skin causes very uncomfortable symptoms. He indeed digs galleries in the epidermis to lay his eggs there. The resulting inflammatory reaction results in intense itching, often unbearable at night. Fortunately, only a minimal quantity of laded eggs will produce adult mites, because the eggs do not all hatch, and the larvae that come out of it do not reach all adulthood.
A risk of bacterial infection
If the wounds resulting from scratch are not neat properly, there is a risk of secondary bacterial infections, as well as a development of eczema.
The typical lesions of scabies, often in the form of small papules and vesicles, appear mainly in areas of fine skin or humid skin, such as between fingers, wrists, elbows, and sometimes around the waist or in the genital region.
These itching can persist even after treatment, because the skin continues to react to the debris of mites and the eggs present in the galleries.
To avoid nocturnal scrapes that can lead to infections, it may be recommended to cut the nails to children. More frequent showers will also limit the risk of infection, and more easily eliminate mites responsible for the scabies.
Scabies, a condition in progress
In 2024, the scabies experienced an upsurge in France and in Europe, especially affecting children, students and care environments.
Infection rates seem to have increased considerably since the post-Cavid period, with notable epidemics in universities and care establishments, where skin-to-skin contact and promiscuity promote its spread. Note that this condition is not linked to a lack of hygiene.
While some studies reveal a locally significant increase, probably in connection with collective living conditions, the exact impact for the entire French territory is not available. Its evaluation is indeed faced with various obstacles.
Scabies is not a compulsory declaration disease, except in the event that it is declared in community. Estimates of the incidence of the crisis are therefore based on the number of medical prescriptions rather than a direct counting of infected people.
However, often, doctors diagnose the disease on the basis of a pruriginous dermatosis belonging to a family or community group, without practicing systematic confirmation of the presence of parasites.
The reason is that the microscopic observation test requires the intervention of a dermatologist, or an expert, which can be difficult to organize. After scraping the skin with a vaccinostyle, the sample is observed under a microscope to determine if it contains parasites. In the event of low contamination, this visual test can be negative. As a result, doctors prefer to prescribe the treatment directly.
Note that the fact that the therapeutic scheme includes not only the treatment of infected people, but also that of their close entourage, which complicates the determination of the incidence of the disease. This tends to inflate contamination figures, as many treated people may not be really carriers of scabies.
A treatment often poorly followed
The three current therapeutic options for the treatment of scabies consist of oral treatment and two local treatments (applied directly to the skin). The three molecules used all have an action on the nervous system of parasites, paralyzing them and leading to their rapid death.
Oral treatment, based on ivermectin (Stromectol® trade name), is the easiest to administer, in particular in a collective context.
The ivermectin is in the form of tablets whose dosage is adjusted according to body weight (up to 6 tablets for an individual weighing more than 76 kg. For children under 6 years of age, the tablet can be crushed to facilitate its ingestion. It must be taken fast, at least two hours before or after a meal. A second dose can be administered 8 to 15 days later.
The two skin treatments (“topical” treatments) are less practical to use than oral treatments. They require a minimum time without rinsing.
The first, Ascabiol® is an emulsion based on benzyl benzoate. It can be used from the age of 1 year as well as in pregnant women. For those over 2 years old, the application must be done in two layers 15 minutes apart, with a timeless contact time of twenty-four hours.
For pregnant women, there will be only one layer under the same conditions, but the data published on the risks of exposure are few. As for the child under the age of two, a single layer will be applied with a contact time from six to twelve hours depending on the age (12, 13 and 14).
The second topical treatment, based on permethrin, is Tobiscab®. It must be applied in a single layer with a minimum eight -hour contact time.
The dose to be applied will depend on age. She goes from a hazelnut to the age of 2 to an entire tube at 12 years old and beyond. It will be necessary to start the operation again 8 to 15 days later.
Whatever treatment, itching may persist several days after the end of treatment. This is due to the presence of dead parasites still present in the skin.
The importance of environmental treatment
Using treatments well is one thing, but treating the environment is just as important to avoid reinfestation.
The day after treatment, whatever it is, it is important to decontaminate sheets, toys, carpets, towels, etc. For this, several options are possible: – Place them in a well closed bag for three days (the mite cannot live at room temperature); – lock them up for three hours in a well closed bag by adding an acaricide; – Machine washing them at 60 ° C.
It is also advisable to apply acaricide to surfaces such as sofa, armchairs, etc. Once this is done, you have to carry out a complete washing of the surfaces where the product has been applied.
Should the entourage of contaminated people be dealt with?
It is generally considered that the entourage of a patient infested by scabies is divided into three circles, according to the degree of contact of individuals.
The 1er Circle consists of people who are in direct contact with them: children, spouse, sexual partners, health personnel … The second circle is made up of the relationships that live or work in the same environment, without necessarily direct contact. Finally, the 3e circle consists of people who occasionally visit the environment of patients.
When a person has been infested, it is important to treat all of these circles, because their members have potentially been in contact with them.
Should we isolate the patient?
Patient isolation can be considered to limit propagation. This is particularly the case in communities (daycares, retirement homes, schools, etc.). Indeed, in these places, contact cannot be avoided.
If it is generally advisable to isolate the patient three days after the start of treatment, it is doubtful that this is sufficient. Indeed, the parasite can live longer than that on the tissues. In addition, we know that for the treatment to be effective, a second dose should be administered a week after the first.
In order to avoid repeated contamination, it is also important to monitor the signs of itching that may manifest in people who frequent the environment of infested individuals.
The World Health Organization is mobilizing
To combat scabies, the World Health Organization (WHO) aims to achieve two objectives worldwide by 2030: integrate your treatment into health services covered by universal health coverage and deploy mass administration campaigns in areas where prevalence reaches or exceeds 10 %.
The countries most affected by the scabies are in particular in South Asia and Southeast Asia, as well as in Latin America, the tropical climate and overcrowding being responsible for the most important prevalences.
To achieve the objectives set, the WHO works in close collaboration with its Member States as well as with various scientific and pharmaceutical partners in order to develop control strategies and response plans to scabs.
The ivermectin, now included in the list of essential WHO drugs to treat scabies, is offered by several suppliers who have been prequalified by the organization.
It also recommends entering these strategies in an integrated approach to the fight against neglected tropical diseases affecting the skin, adapted to specific pathologies of each country. It is a question of making an economically viable the interventions antigal and facilitating their adoption rapid.
