Do you often scratch your head, your scalp is covered with red patches, dandruff forms? It’s probably eczema. Corn this generic term is not sufficient to characterize the disease. Basically, three forms of eczema can affect the scalp: seborrheic dermatitis, atopic eczema, and allergic eczema. Only a dermatologist can make an accurate diagnosis. Most of the time, the physical examination is sufficient and there is no need to take a skin biopsy.
Seborrheic dermatitis: from dandruff to inflammation
Seborrheic dermatitis is the most common form of scalp eczema. Very often the disease has startedin early childhood. These are the famous “cradle cap ‘ of the newborn.
When seborrheic dermatitis occurs in adults, the skin of the skull is abnormally dry and loses scales. Sometimes it’s just simple dandruff, unsightly but totally benign. In severe forms, the scalp is very inflamed and the plaques ooze.
The diagnosis is quite simple. “Usually, the disease does not affect the entire scalp. The presence of yellowish crusts, most often located at the edge of the scalp, points us to seborrheic dermatitis. Sometimes the face is affected in the nasolabial folds and eyebrows ”, specifies Dr. Claire-Alice de Salins, dermatologist within the Bretagne-Sud hospital group in Lorient and member of the ResoEczema.
In some men, the beard is also affected. It is advisable to shave it so as not to aggravate the symptoms.
Malassezia yeast involved
The attack on the scalp is due to the proliferation of yeasts, of the Malassezia genus, which develops particularly in an oily environment, such as the sebum of the skin. “Fatigue and stress are also aggravating factors”, estimates the dermatologist.
In the simplest cases, theregular use of anti-dandruff shampoo (based on zinc pyrithione, in particular) is recommended.
If this is not enough, and especially during a flare-up, the dermatologist prescribes an antifungal shampoo, based on ciclopirox olamine, which will destroy the yeast.
“We start with an attack treatment twice a week for a month, then once a week for three months. To be effective, a sufficiently long break time of at least five minutes must be observed. Often, I advise the patient to shampoo, then take a shower before rinsing off the product, ”explains Dr de Salins.
When the scalp is very inflamed, it is possible to complete the treatment by applying, occasionally, a cortisone-based lotion.
Atopic eczema: a family history
Some forms of atopic eczema, also called atopic dermatitis, can affect the head and neck and extend to the scalp. “They mainly concern adolescents and adults,” notes Dr de Salins.
A genetic ground
This disease develops in people who are genetically predisposed. In general, this “atopic terrain» Is transmitted from one generation to the next, within the same family. “People who have atopic eczema on the scalp also have it on other parts of the body. They can have other atopic manifestations such as hay fever or asthma. Family history also helps us to establish the diagnosis, ”adds Dr de Salins.
Several levels of treatment
The first treatment is to apply a topical corticosteroid lotion (based on cortisone, a very effective anti-inflammatory), once a day, for several weeks, while the scalp regains its normal appearance.
Unfortunately, many patients, fearing possible side effects, do not apply enough product for the treatment to be effective. To reassure them, the Lorient hospital recently opened a “school of atopy”. “It is about helping patients to express their fears and beliefs, and to be convinced of the benefits of these treatments,” explains Dr de Salins.
“Eczema is a chronic disease,” she recalls. Topical corticosteroids will not cure it, but treat the inflammatory condition and help control the disease. “
When the red patches spread to the face, the dermatologist has the option of prescribing another local treatment: topical tacrolimus. This ointment, which does not contain cortisone, is more suitable for treating the face than topical corticosteroids.
Finally, in the most severe cases, we appeal to so-called “systemic treatments»: Ciclosporin, methotrexate or – the latest molecule to hit the market – dupilumab.
The ciclosporin is generally taken in tablets morning and evening. the methotrexate is offered orally or by injection, once a week. For the dupilumab, the patient can self-inject the product, once every two weeks, after learning the procedure from a nurse. At present, this latest generation drug is reserved for adults and adolescents over 12 years old.
Allergic eczema: hair dyes often involved
Inflammation of the scalp is sometimes due to an allergy. We then speak ofcontact eczema. This type of reaction can occur, for example, after coloring the hair. “This acute eczema is much more vesicular. We often see the appearance of small blisters full of liquid. After hair coloring, they occur in particular in the ears and neck », Specifies Dr de Salins.
An allergological test will make it possible to confirm the allergy to the offending product.
In order for the scalp to resume its normal appearance, it is, of course, necessary to avoid contact with the allergenic substancee. For his part, the dermatologist prescribes a topical corticosteroid treatment to calm the inflammation. “If there is no rapid improvement, you must consult your doctor again to check whether it is really allergic eczema or another pathological”, recommends Dr. de Salins.