Overview on pharmacological management of psoriasis

By : ph Abeer abd el rahman

What is psoriasis? • psoriasis is one of the most baffling and

persistent of skin disorders.• It's characterized by skin cells that multiply up

to 10 times faster than normal.• As underlying cells reach the skin's surface

and die, their sheer volume causes raised, red plaques covered with white scales.

Causes of psoriasis• Psoriasis is an autoimmune disease.• Autoimmunity occurs when the immune system

automatically launches an inflammatory response against your own body.

• When the immune system functions properly, it protects the body against any “invaders” such as bacteria, viruses or other pathogens.

• But in people with psoriasis ,the immune system goes into action even without these invaders.

• Instead, the immune system fights the body’s own tissues.

• TNF-alpha (tumour necrosis factor alpha) is produced in excess amounts by activated T cells. The messages communicated by TNF alpha lead to the rapid growth of skin cells found in psoriasis.

The role of inflammation

• Inflammation is one of the weapons used by the immune system to fight an invader.

• The inflammatory response starts with T cells recognize something as an invader.

• This attack is carried out by cytokines, which are proteins that help control the immune system’s inflammatory response ,causing the blood vessels to expand and send more immune cel ls to different parts of the body .

Treating the immune system

• The immune system is not only the key to what causes psoriatic disease—it may be the key to treating it !.

• Through the process of suppressing immune response we can manage psoriasis.

(1) Ciclosporin • is highly effective in severe psoriasis. • It inhibits epidermal hyperproliferation by

suppressing T lymphocyte activity in the dermis and epidermis of psoriatic skin.

2) Biological immunomodulators• A number of biologic medications have been

introduced to treat psoriasis and other autoimmune diseases by binding to TNF alpha and preventing it from communicating with cells for example:

• Adalimumab, Etanercept, Infliximab, Ixekizumab, Secukinumab& Ustekinumab which are mainly monoclonal antibodies directed against TNF-alpha except for etanrecept which is a synthetic receptor for TNF-alpha to bind instead of the receptors skin cells.

•

3 )Methotrexate• methotrexate acts by decreasing the production of

skin cells at higher (anti-cancer) doses by acting as an antimetabolite because it antagonises the B vitamin, folic acid. It reduces pyrimidines, purines and methylation of DNA.

• Suppress inflammation through increasing intracellular adenosine “a purine nucleoside”

• Methotrexate also has immune modulatory effects. It reduces the homing of T cells to the skin and alters immune signals sent between cells (inhibits cytokine release from and decreases TNF-α, IL-10, IL-12).

3) retinoids

• Related to vitamin A.• this group of drugs may reduce the production

of keratinocytes and decreases inflammation if you have severe psoriasis that doesn't respond to other therapies.

4) Topical corticosteroids• These powerful anti-inflammatory drugs are the most

frequently prescribed medications for treating mild to moderate psoriasis.

• They slow cell turnover by suppressing the immune system, which reduces inflammation and relieves associated itching.

5) Vitamin D analogues.

• These synthetic forms of vitamin D slow down the growth of skin cells.

• Calcipotriene (Dovonex) or Calcitriol (Rocaltrol) may be used alone to treat mild to moderate psoriasis or in combination with other topical medications or phototherapy.

• This treatment can irritate the skin.

6) Anthralin

• Anthralin is an effective topical drug for psoriasis therapy.

• This medication is believed to normalize DNA activity in skin cells.

• Anthralin (Dritho-Scalp) also can remove scale, making the skin smoother However, anthralin can irritate skin.

7) Calcineurin inhibitors

• calcineurin inhibitors — tacrolimus (Prograf) and pimecrolimus (Elidel) — are approved only for the treatment of atopic dermatitis, but studies have shown them to be effective at times in the treatment of psoriasis.

• Calcineurin inhibitors are thought to disrupt the activation of T cells, which, in turn, reduces inflammation and plaque buildup.

8) Salicylic acid

• Available over-the-counter (nonprescription) and by prescription.

• salicylic acid promotes sloughing of dead skin cells and reduces scaling.

9) Coal tar

• A thick, black byproduct of the manufacture of petroleum products and coal.

• It reduces scaling, itching and inflammation. Exactly how it works isn't known.

• https://www.psoriasis.org/research/science-of-psoriasis/immune-system

• http://www.papaa.org/psoriasis-treatments/immunosuppressants-and-biologics

• http://www.mayoclinic.org/diseases-conditions/psoriasis/basics/treatment/con-20030838

• https://www.ncbi.nlm.nih.gov/pubmed/6693604