Treatment of Psoriasis

Topical treatments. These are the treatment of choice for localised forms and small‑scale psoriasis. These treatments have the fewest side effects, but are inconvenient and must be applied continuously. There are various types of topical treatments. The most widely used and effective are topical corticosteroids, which come in various forms and doses. The most suitable should be selected according to the characteristics of the lesions, their extent and the area to be treated. To prevent cutaneous atrophy and the possible appearance of stretch marks, these must not be used continuously. You can also use vitamin D analogues, topical retinoids, coal tar derivatives, topical immunomodulators, emollients (moisturisers), and keratolytic substances (which help to peel). They can be combined, rotated or used in sequence, in order to enhance the effectiveness of each treatment and avoid the side effects associated with continuous application.

Phototherapy. Exposure to ultraviolet (UV) rays from sunlight or artificial light slows down the elimination of dead skin cells and reduces flaking and inflammation. Treatment with narrow‑band ultraviolet B (UVB‑BE) radiation, and ultraviolet A (UVA) in combination with psoralenes (an oral UVA radiation enhancer) (PUVA) are effective treatments for extensive forms of psoriasis or forms that affect certain locations (the palms and/or soles of feet) that do not respond adequately to topical treatments. Phototherapy can be difficult to perform on some patients due to their availability (about 3 sessions per week are usually needed), as well as the possible long‑term side effects (increased photoageing and a greater risk of skin cancer).

Systemic treatment. Systemic treatments are indicated in cases of extensive or serious psoriasis. The drugs are usually effective, but they are not free from important side effects, making frequent controls necessary (analytical and clinical). Cyclosporine is a very effective, fast‑acting drug, but can cause outbreaks of psoriasis when the treatment is stopped, meaning the dose has to be reduced gradually. It requires the blood pressure and kidney function to be controlled. Because of the potential risk of renal effects, it is recommended that this drug be used in short cycles of 3‑4 months. Methotrexate is a drug that takes a little longer to work than cyclosporine, but usually manages to control psoriasis for long periods of time. It requires the liver function to be controlled and it is not advisable to exceed the maximum total dose due to the risk of liver damage in the long term. Acitretin is a less‑effective drug, but it can be very useful in a subgroup of patients, especially in combination with phototherapy. It requires triglyceride and cholesterol levels to be controlled and usually causes increased dryness of the skin and mucous membranes (lips). This drug can cause foetal malformations in pregnant women, even up to 2 years post‑treatment, so it is not recommended for use in women of childbearing age.

Biological treatments. Biological treatments (etanercept, infliximab, adalimumab, ustekinumab, secukinumab, and ixekizumab) are recent drugs. Biological treatments are indicated in severe forms of psoriasis. According to the European consensus, these are second‑line drugs and should only be prescribed for patients who have not responded to at least two classic systemic treatments (phototherapy, methotrexate, cyclosporine, or acitretin), or where these could not be prescribed because of some contraindication, the patient has suffered side effects, or the recommended cumulative dose has been exceeded.

Depending on the drug, they are administered through a subcutaneous injection (etanercept, adalimumab, ustekinumab, secukinumab, and ixekizumab) or intravenously, in other words, directly into a vein (infliximab). In the case of subcutaneous administration, the patient usually self‑administers the medication at home, while for intravenous treatments, the patient is required to spend a few hours in the hospital.