Psoriasis is an inflammatory disease that develops in people who are genetically predisposed. During a push, the skin thickens in some places and turns red.
The appearance of these plaques is the result of a runaway immune system. In reaction to an attack (bacterial or viral infection, stress …), lymphocytes, immune cells, become overactive. They will then excessively stimulate the skin cells. ” Instead of renewing in 28 days, they will do it in two weeks », Explains Dr Marc Perrussel, vice-president of the National Union of Dermatologists and responsible for a specialist consultation at the Rennes University Hospital.
It is not clear why psoriasis occurs in one place rather than another. Different hypotheses are put forward, according to the dermatologist: “In the scalp, local bacterial overgrowth due to sweating could be an explanation. In other places (elbows, knees, belt …), friction could explain the appearance of plaques. ”
One thing is certain: psoriasis is not a contagious disease, contrary to a misconception that is still well entrenched today.
A disease that manifests itself at any age
Whatever its form, psoriasis varies greatly from one person to another, with an alternation of unpredictable outbreaks and periods of remission of varying lengths. The disease can occur at any age, in a baby or an adult, “At 7 days as at 77 years”, says Professor Perrussel.
Forms of psoriasis in children
Children with psoriasis develop the same shapes as adults (plaque psoriasis, drops …). Psoriasis of the face is, however, rarer in children.
In 95% of cases, clinical examination of the skinsufficient to make the diagnosis. In toddlers (0-3 months), plaques related to diaper maceration may appear on the buttocks. Dr Perrussel talks about “Swaddling psoriasis”.
Not to be confused with eczema
In addition, the cradle cap that forms on the scalp are, in 30% of cases, real psoriatic manifestations. However, they can be confused with atopic dermatitis, a form of eczema.
In video: Can we treat all types of psoriasis?
Psoriasis in children: many possible treatments
The treatments are the same as for adults, at pediatric doses. We always start with local treatments (topical corticosteroids) and, in case of failure, we move on to systemic treatments. In the event that guttate psoriasis develops after an ENT infection, antibiotic treatment may be attempted.
The treatment is adapted according to the degree of severity disease, in children as well as in adults. The therapeutic arsenal is very vast. If one molecule doesn’t work, we try another.
“Psoriasis is a disease that can be treated, even if it cannot be cured,” recalls the dermatologist.
Hydration, the basis of treatment
First of all, it is necessary prevent the skin from drying out, irritation promoting the appearance of plaques. “Hydration is the first treatment for the disease”, emphasizes the dermatologist who recommends the daily use of special “dry skin” creams or some hydrating baths, twice a week, in which we throw “a handful or two of wheat or corn starch”.
For mild psoriasis, local corticosteroids or some products combining vitamin D and a topical corticosteroide can be applied to the plates. “These products give very good results. They should be used as an attack treatment to eliminate plaques; then twice a week for maintenance treatment, for life, ”explains the dermatologist.
There are different possibilities to treat more extensive psoriasis.
1. PUVA therapy. It is not recommended before the age of 8-10 years. It consists of exposing the skin to ultraviolet rays. The sessions are practiced in the cabin. But, like the sun’s rays, this type of treatment increases the risk of skin cancer in the long run. As a precaution, the number of sessions is limited to two or three for ten weeks, and should not exceed 150 throughout life.
2. Retinoids. The best known of these is marketed under the name of Soriatane. This medicine limits the excessive renewal of skin cells and refines the skin. It is effective, but at the cost of significant side effects. It is, in particular, toxic in pregnant women and should never be prescribed to women of childbearing age.
3. Methotrexate. “Today is the standard treatment in psoriasis. It is prescribed in an anti-inflammatory dose, ”explains Dr Perrussel. The medication is taken either as a tablet or by injection, once a week. Patients should be biologically monitored, by regular blood tests, in order to check that they do not develop side effects in particular on the level of the liver.
“If the methotrexate remains ineffective after three months, it is necessary to change the treatment”, specifies the dermatologist.
4. Cyclosporin. This drug, known as immunosuppressant (anti-rejection) after organ transplant, is also active in psoriasis. “We get very quickly a skin whitening, that is to say a disappearance of the plaques ”, estimates Dr. Perrussel. Cyclosporin is prescribed in emergency situations to deal with a strong outbreak of psoriasis. Here again, it is necessary to watch for the appearance of possible side effects, in particular a risk of arterial hypertension and renal failure. Every month, a blood pressure measurement and one blood creatinine test must be performed. To limit the risks, ciclosporin should not not be prescribed for more than two years continuously.
5. ApremilastSold under the name Otezla, it is taken in tablets. It effectively calms inflammation of the skin. “It reduces the severity of psoriasis by 50%,” notes the dermatologist. But this molecule has side effects (significant weight loss, diarrhea, depression …). It can only be prescribed after failure of at least one other systemic treatment.
These molecules have changed the lives of patients with very extensive psoriasis. They target a particular mechanism of the disease: the hyperactivity of lymphocytes which leads to excessive renewal of the skin.
There are several biotherapy drugs, each acting on specific mediators: anti-TNF alpha, anti-IL12, anti-IL23 or anti-IL 17. ” These molecules improve psoriasis by 75% to 100%. These drugs, which can only be prescribed in the hospital, are administered by injection, on an outpatient basis, at a rate that varies from one week to three months, ”explains the dermatologist. This type of treatment is reserved for severe cases, after failure of two conventional systemic treatments (puvatherapy, retinoids, methotrexate, ciclosporin …).
These biotherapy are immunomodulators, which means that they modify the body’s immune defenses. Under treatment, patients therefore become more susceptible to infections. They are recommended, as a precaution, to be vaccinated against influenza and pneumococcus.
No more risk of Covid-19 under biotherapy
In the current epidemic context, it was feared that patients undergoing biotherapy would be exposed to an additional risk of Covid-19. Fortunately, it is not. Studies have shown that not only do patients not get infected with the coronavirus more frequently, but they do not develop more severe forms. Conclusion of Dr Perrussel: ” it is important not to stop its treatment! “.
Living well with your psoriasis
Treatments help a lot, but it is also very important that patients come to terms with their illness and learn to live with it. from the youngest age.
At the same time, simple advice makes it possible to better endure the disease, on a daily basis:
- Wear some loose clothing to avoid friction on the skin.
- Avoid alcohol-based deodorantsl and the scented productss that can be irritating.
- Wash with a surgras soap.
For young girls, makeup can help camouflage imperfections, some brands having developed specific ranges.
• The France psoriasis patient association will organize a vast communication campaign on the disease, on the occasion of the 17th World Psoriasis Day on October 29, 2020. More info on his site.
• The Resopso network of dermatologists provides detailed information and the latest news about the disease. To discover on his site.