Why Do Psoriasis White Patches Linger After a Flare-Up?
One of the most common lasting effects of psoriasis flare-ups is the change in skin pigmentation. You may notice white spots or dark spots after the psoriasis plaques fade away, because the inflammation alters the pigment cells called melanocytes.
However, these changes are temporary. The quicker and better you take control of psoriasis, the more you reduce the risk of scarring and abnormal skin pigmentation.
What Happens to Your Skin During a Flare-Up?
Psoriasis is a chronic skin condition characterized by red patches on the skin, which are covered by silvery scales. The disease activity changes over time, with occasional flare-ups.
The problem occurs in the epidermis, which makes the top five layers of the skin. The keratinocytes are skin cells produced in the deepest layer of the epidermis, and their key role is to produce keratin (a protein that helps form hair, nails and skin).
In healthy individuals, keratinocytes start to mature and move from the deepest layer to the surface, and shed without being noticed, in about one month. In psoriasis sufferers, these cells multiply very quickly and move to the surface rapidly, in just few days. The skin can’t manage to shed these keratinocytes quickly enough, and they will build up in a form of think patches or plaques.
The silvery scales on top are dead cells of the plaques that are shed. Beneath the epidermis, there is another layer called dermis. Dermis contains blood and lymphatic vessels and is also affected by psoriasis – this is why the skin underneath the patches is red and swollen.
During a flare-up the skin is inflamed, and this inflammation destroys melanocytes, a type of cells that produce the pigment of the skin. Melanocytes are located superficially in epidermis, but during a flare up they drop into the dermis. Many of these cells get destroyed in the process.
The result: they start to behave like a natural tattoo until the body (especially the immune system) cleans them up. During this time some people may notice changes in their skin color, even after the flare-up fades away.
A 2013 study featured in the Journal of Investigative Dermatology also found there are two immune system proteins (IL -17 and TNF-alpha), which cause inflammation in psoriasis also interfere with the production of the melanocytes.
Preventing Changes in Skin Color
- Take good care of your skin during both flare-ups and quiet periods. See your doctor regularly, as your treatment may be adjusted over time, to better manage your condition.
- Avoid skin irritation and scars by keeping your skin moist – use emollients twice a day and creams with lactic, glyolic or salicylic acid(these ingredients help reduce itching and scaling). Avoid shaving, if possible.
- Itchy skin makes you more likely to scratch that area, and therefore the scars and skin discoloration will last longer. Avoid scratching by applying an ice pack on the itchy area.
- Spend some time in the sun, as the UV rays help heal the skin. Make sure you don’t spend more than 20-30 minutes a day in the sun.
- Decrease the overall inflammation if your body, with regular exercise (be cautious and avoid skin injuries) and a healthy diet (avoid red meat, and highly processed foods as they promote inflammation).