Management of psoriasis

Source: Wikipedia

1. Cognitive behaviour therapy

2. Topical Rx

Bath solutions and moisturizers, mineral oil, and petroleum jelly may help soothe affected skin and reduce the dryness which accompanies the build-up of skin on psoriatic plaques. Ointments and creams containing coal tar, dithranol (anthralin), corticosteroids like desoximetasone (Topicort), fluocinonide, vitamin D3 analogues (for example, calcipotriol), and retinoids are routinely used. Argan oil has also been used with some promising results. The mechanism of action of each is probably different but they all help to normalise skin cell production and reduce inflammation. Activated vitamin D and its analogues are highly effective inhibitors of skin cell proliferation.

The disadvantages of topical agents are variably that they can often irritate normal skin, can be time consuming and awkward to apply, cannot be used for long periods, can stain clothing or have a strong odour. As a result, it is sometimes difficult for people to maintain the regular application of these medications. Abrupt withdrawal of some topical agents, particularly corticosteroids, can cause an aggressive recurrence of the condition. This is known as a rebound of the condition.

Some topical agents are used in conjunction with other therapies, especially phototherapy.

3. Phototherapy

Daily, short, non-burning exposure to sunlight helped to clear or improve psoriasis in some patients. Niels Finsen was the first physician to investigate the therapeutic effects of sunlight scientifically.

Ultraviolet wavelengths are subdivided into UVA (380–315 nm) UVB (315–280 nm), and UVC...

4. Photochemotherapy

Psoralen and ultraviolet A phototherapy (PUVA) combines the oral or topical administration of psoralen with exposure to ultraviolet A (UVA) light. Precisely how PUVA works is not known. The mechanism of action probably involves activation of psoralen by UVA light which inhibits the abnormally rapid production of the cells in psoriatic skin. There are multiple mechanisms of action associated with PUVA, including effects on the skin immune system.

PUVA is associated with nausea, headache, fatigue, burning, and itching. Long-term treatment is associated with squamous cell carcinoma (not with melanoma).

5. Systemic treatment

Psoriasis that is resistant to topical treatment and phototherapy is treated with systemic treatment. Patients undergoing systemic treatment are required to have regular blood and liver function tests because of the toxicity of the medication. Pregnancy must be avoided for the majority of these treatments. Most people experience a recurrence of psoriasis after systemic treatment is discontinued.

The three main traditional systemic treatments are methotrexate, cyclosporine and retinoids. Methotrexate and cyclosporine are immunosuppressant drugs; retinoids are synthetic forms of vitamin A.

Other additional drugs, not specifically licensed for psoriasis, have been found to be effective. These include the antimetabolites tioguanine, mercaptopurine and fluorouracil, the cytotoxic agents hydroxyurea and paclitaxel, alkylating agents chlorambucil and cyclophosphamide, some DMARDs like sulfasalazine, colchicine, dapsone, the immunosuppressants mycophenolate mofetil, azathioprine and oral tacrolimus. These have all been used effectively to treat psoriasis when other treatments have failed.

Although not licensed in many other countries, fumaric acid esters have also been used to treat severe psoriasis in Germany for over 20 years.

There is also some evidence for beneficial effect on psoriasis of insulin-sensitizing drugs (thiazolidinediones like pioglitazone and rosiglitazone, and a more modest effect is described for metformin), somatostatin, bromocriptine, and some lipid-lowering drugs from the group of statines (like simvastatin), and omega-3 fatty acid supplements. For all those drugs it is hypothesised that their antipsoriatic activity comes from their immunomodulatory properties.

There are also case reports and small trials describing beneficial effects of yohimbine (effect is thought to be secondary to its insulin-lowering and growth hormone lowering properties), ketotifen (effect is thought to be secondary to its ability to dampen release of inflammatory mediators) and albuterol (beta-adrenergic agonist).

Antihistamine drugs generally do not help to improve psoriasis lesions, but they may be of use to reduce itching and also are helpful in cases where psoriasis coexists with skin allergy, for example chronic urticaria. Some antihistamines have sedative properties, thus might aid to improve sleep and reduce anxiety in psoriasis patients.

Antidepressant medications may help to reduce comorbid depression, anxiety, social isolation, improve sleep and in some cases reduce itching (primarily due to antihistamine effects of tricyclic antidepressants and some SSRIs). Naltrexone, an opioid antagonist, and pregabalin or gabapentin, benzodiazepine anxiolytics are also of use in severe itching.

NSAIDs generally do not help to improve psoriatic arthritis itself, but they might provide rapid symptomatic relief from pain and swelling.

Biologics are manufactured proteins that interrupt the immune process involved in psoriasis. Unlike generalised immunosuppressant therapies such as methotrexate, biologics focus on specific aspects of the immune function leading to psoriasis. These drugs (interleukin antagonists) are relatively new, and their long-term impact on immune function is unknown, but they have proven effective in treating psoriasis and psoriatic arthritis. They include Amevive, Enbrel, Humira, Remicade and Raptiva. Raptiva was withdrawn by its maker from the US market in April, 2009. Biologics are usually given by self-injection or in a doctor's office. They are very expensive and only suitable for very few patients with severe psoriasis. Ustekinumab (IL-12 and IL-23 blocker) shows hopeful results for psoriasis therapy.

Noting that botulinum toxin has been shown to have an effect on inhibiting neurogenic inflammation, and evidence suggesting the role of neurogenic inflammation in the pathogenesis of psoriasis, the University of Minnesota has begun a clinical trial to follow up on the observation that patients treated with botulinum toxin for dystonia had dramatic improvement in psoriasis.