Nummular Psoriasis: Causes, Symptoms and Treatments

The psoriasis is a chronic inflammatory disease that primarily manifests in the skin and joints. It presents as red, thick plaques that shed. Psoriasis is characterised by an excessive renewal and accumulation of epidermal cells, leading to a local inflammation. Therefore, it is a relatively common disease, which is neither contagious nor of psychological origin.

Of all the forms of psoriasis, nummular psoriasis is the least known to the general public. The reason for this is that nummular psoriasis is less common than the so-called "plaque" psoriasis, which is the classic form.

The causes of nummular psoriasis are identical to those of classic psoriasis. It is an autoimmune disease caused by a failure of the body's immune system. The lymphocytes present in the epidermis are abundant. They produce inflammatory cells (cytokines Il-17, Il-22, TNF-alpha). These stimulate the proliferation of keratinocytes, which induces a faster cellular renewal, typically shifting from three weeks to three days. The result is an accumulation of immature keratinocytes on the skin's surface, increasing the thickness of the outer layer (the stratum corneum).

Nummular psoriasis is a condition that is neither dangerous nor contagious. This form of psoriasis is accompanied by several symptoms. The main characteristic of nummular psoriasis, like all forms of psoriasis, is the appearance of red patches covered with scales. The difference between nummular psoriasis and classic psoriasis lies in the size of the patches. Those of nummular psoriasis have a unique rounded shape, comparable in size to a coin, hence the name 'nummular', which means 'coin' in Latin. These patches can itch and provide a sensation of warmth. Furthermore, nummular psoriasis can appear on several areas of the human body such as the nipples, nails, scalp, or even the face.

Today, there is still no treatment that can permanently cure psoriasis. However, it is still possible to alleviate the symptoms of the disease by using treatments containing ingredients that act on psoriasis.

• Dermocorticoid-based treatments: Inflammation can be reduced by using a treatment containing a dermocorticoid such as cortisone. Topically applied, dermocorticoids help to soothe the skin by combating inflammation. They inhibit the NF-kB transcription factor by activating the transcription of the IkB gene, thereby conferring anti-inflammatory effects. Dermocorticoids are available in the form of ointment, lotion, or cream.

• The use of keratolytic active-based skincare: Psoriasis lesions often present a large number of scales or immature dead cells that cannot be naturally eliminated. Keratolytic actives help to remove these dead cells and promote the elimination of scales. Among these actives we can mention: the salicylic acid, the glycolic acid, urea, etc.

• The phototherapy : This type of therapy is intended for lesions covering at least 10% of the body surface. It involvesusing a method to treat psoriasis by projecting ultraviolet rays onto the affected area. The aim is to reproduce the beneficial effects of the sun on psoriasis.

• Moisturising care: To reduce irritation, it is appropriate to moisturise the skin using a cream or lotion. Moisturising helps to soothe itching. It is recommended to moisturise the skin after each shave.

• The use of essential oils: Some essential oils can also help to alleviate psoriasis. The most commonly used for this purpose are the lavender essential oil, the tea tree essential oil or even chamomile essential oil. However, it is advised to only use them under the supervision of a professional.