Seborrheic dermatitis of the scalp: causes, symptoms and natural remedies

Dermatitis or seborrhoeic dermatitis of the scalp is an inflammatory skin disease (or dermatosis). It takes the form of oily flakes or dandruff on the scalp, mainly affecting the forehead, around the ears (and sometimes even the nasal concha and external auditory canal), and sometimes the face itself, particularly the forehead and T-zone (eyebrows, nose and nasolabial folds). These areas are generally the richest in sebum and therefore favourable to the proliferation of fungi. In men, the sternum may also be affected.

On light-coloured skin, the patches may be accompanied by redness (the surface of which is a whitish or yellowish colour similar to that of pus) with skin particles that may be detached, while in dark-coloured skin there is often associated depigmentation. In almost all cases, pruritus (itching) is reported.

The diagnosis is clinical, and it is sometimes difficult to distinguish between incipient scalp psoriasis, especially if there is little redness, eczema or ringworm of the scalp. In these cases, the concomitant involvement of other areas of the body, a possible atopic background, the course of the disease and a mycological sample of the scales can help guide the diagnosis.

Seborrhoeic dermatitis is a benign, non-contagious disease, but it is chronic, with recurrent outbreaks. Unsightly and often the cause of embarrassment, its visible lesions can have a detrimental effect on quality of life. It mainly affects men, with six men affected for every woman. It can also affect infants, known as "cradle cap". After the age of 40, the disease is less common and almost exclusively affects men.

Seborrhoeic dermatitis, like tinea versicolor is considered to be a fungal infection caused by the multiplication of a yeast of the genus Malassezia, which is normally present in our skin commensal flora (skin microbiota). In some people, this microbiota is altered (lifestyle, stress, antibiotics, etc.) and the Malassezia yeast proliferates abnormally. However, this is not a contagious disease, but a kind of hypersensitivity of the skin to the abnormal presence of this fungus.

Factors favouring alteration of the skin microbiota are often found, such as aggressive hair and scalp care: chemical straightening, excessive drying, etc. Seborrhoeic dermatitis is therefore all the more common in Afro-Caribbean populations, who are more prone to this type of cosmetic practice.

Similarly, the recurrent application of greasy or occlusive products (such as Vaseline, commonly applied to textured hair) can sometimes encourage this condition.

Insofar as recurrences are very frequent, it can almost be considered a chronic dermatosis, with treatment in two stages: first an attack treatment, then a maintenance treatment lasting several months, to limit the frequency and intensity of relapses.

Typically, anti-fungal shampoos are applied for several days or weeks, followed by milder lotions or shampoos. Sometimes, if the flare-ups are very bothersome (particularly itching and flaking), cortisone lotions, gels or foams may be prescribed to relieve the symptoms, or even keratolytics.

In some cases of facial involvement, topical calcineurin inhibitors can rapidly relieve symptoms and limit recurrence.

Finally, lifestyle changes can sometimes be useful (stopping the application of oily and occlusive emollients, improving diet, stress management, etc.).

The aim is to moisturise the scalp without overloading it with occlusive fats, and to gently eliminate dandruff. An anti-inflammatory, astringent and anti-fungal action is often also useful.

Essential oils are known to be effective in the natural treatment of seborrhoeic dermatitis. The active ingredients in zinc and tea tree have an anti-inflammatory and regulating action (by limiting excessive sebum production and combating the fungus). Others, such as Urea, Nigella and Jojoba, have soothing and moisturising properties to combat itching and inflammation. Finally, plant-derived salicylic acid can help rebalance the skin's flora by stimulating cell renewal.

For this condition, you can use a neutral shampoo with lime blossom hydrosol, to which you can add keratolytic and anti-inflammatory agents (plant-derived salicylic acid, Urea and Algo'zinc) and soothing, anti-fungal essential oils such as ORGANIC Egyptian Geranium, Tea Tree, Spike Lavender and Fine Lavender.

To moisturise the scalp, you can then make a lotion based on Aloe vera gel, Tea tree essential oil or Palmarosa essential oil, and Nigella oil or Jojoba oil, as well as active ingredients such as Salicylic acid, Urea or Zinc.

Finally, you can continue your usual haircare routine by applying a hair mask, haircare oil or moisturiser, taking care not to spread them on the scalp, but only on the lengths and ends.