#psoriasis - review on the best treatment options.

In deciding which therapy to use, many factors must be taken into consideration, including safety, efficacy, availability, and cost. Long-term side effects will, of course, become better known as experience with each therapy grows. In particular, biologic medications are already in their second decade of use in rheumatology, but there is much less experience than with more traditional therapies. Comparisons of efficacy between therapies are hampered by the lack of quality comparative clinical trials. 

The first approach of the patients with psoriasis who require systemic therapy is done by performing a complete history and cutaneous examination. If there are no contraindications, narrow-band-UVB phototherapy with or without acitretin is usually started. If phototherapy is not an option due to logistical issues, methotrexate can be used. Occasionally PUVA is considered for patients with extremely thick plaques or patients with type V or VI skin. For many patients these conventional treatments are very effective. If there is not an adequate response after approximately 12 weeks, then patients may be switched to the alternative therapy or switched to a biologic medication. Cyclosporine is usually reserved for short-term treatment of flares, followed by transitioning to other therapies for long-term control.

In choosing a biologic medication, several situations may point to the use of one over another:

1. Etanercept is the most used biologic medication for psoriasis, in part because dermatologists have the most accumulated experience with it.
2. Obese patients may experience better efficacy with medications dosed using weight-based calculations with infliximab or ustekinumab.
3. Infliximab is one of the most efficacious therapies for psoriasis and in addition works very quickly. This may be the best treatment for patients with extremely severe psoriasis and in patients where hospitalization is a consideration.
4. Adalimumab and ustekinumab have also shown impressive results.

However, some longer-term trials have shown some loss of efficacy when using biologic medications. It may then become necessary to switch those patients to a different biologic medication. There are two different options: changing to a medication in the same class (i.e. from a TNF inhibitor to another TNF inhibitor), or changing to a medication in a different class (i.e. from a TNF inhibitor to an IL 12/23 blocker such as ustekinumab). There is no strong evidence in the literature to differentiate between these two options till this moment.