Evaluation of Spa Therapy in the Treatment of Plaque Psoriasis

Psoriasis is one of the most common skin diseases, affecting 2-3% of the general population; more than 1 million people in France.

This auto-immune erythematosquamous inflammatory dermatosis occurs on a particular genetic background and has a chronic course. Psoriasis has a history as an indication for dermatological spa treatment (water cures in the Dead Sea). As these treatments are a combination of balneotherapy and heliotherapy, many recent studies have attempted to assess the value and position the relative benefit of each therapeutic element. Over the last four decades various different phototherapy techniques have been widely used in the treatment of psoriasis. The thermal option for many psoriasis patients depends on personal choice, or their doctor's or dermatologist's recommendation. In 1994 only one third of the 16,875 spa treatments for dermatological conditions (about 5625 cures) were for psoriasis, suggesting that spa treatment is underused as a treatment for psoriasis. Nobody can challenge the therapeutic contribution of biotherapy in the treatment of anatomically destructive diseases such as rheumatoid arthritis and psoriatic arthritis, but the use of these treatments is not without risk and economic impact. There is thus a need for less intensive treatments that have little risk of serious side effects and are less expensive.

The use of spa therapy in psoriasis should be understood as complementary and not an alternative to all other treatments. The choice of treatment is guided by the patient's characteristics and pathology (concomitant diseases, extent of lesions, treatment history) and the specialty (adverse effects, cumulative dose). In psoriasis it may be necessary to use different lines of treatment because psoriasis is a lifetime disease. Side effects of systemic treatments such as biotherapy, cyclosporine, methotrexate, synthetic retinoids, and also phototherapy (PUVA and UVB) are cumulative over time. A course of spa treatment should allow a respite before resorting to other systemic therapy.

However, the spa dermatology still suffers from a lack of large-scale evaluation and especially an objective assessment using reliable methodologies that limit bias. This is the purpose of this study.

There are no randomized controlled multicenter clinical trials evaluating spa treatment for psoriasis, although an Italian non-randomized study included a few dozen patients and confirmed the clinical benefit of the treatment.

Inclusion criteria

• Both sexes, over 18 years of age, patients with plaque psoriasis for more than one year diagnosed by a dermatologist
• Stable treatment in the last 6 months
• DLQI score > 10
• patients volunteering for spa treatment within 6 weeks
• consenting to participate to the study with informed consent form signed after appropriate information
• Affiliation to the French social security system or equivalent

Exclusion criteria

• Pregnancy, parturient or breast feeding
• Psychiatric illness or social situation that would preclude study compliance
• Refusal of consent
• Refusal of spa treatment
• Contra-indication to spa treatment
• Phototherapy in the last 3 months
• Guttate, pustular or erythrodermic psoriasis Isolated nail psoriasis
• Spa therapy in the past year
• Person deprived of liberty or under legal guardianship