In this study, we compared a new combination ointment containing both calcipotriol and betamethasone dipropionate with betamethasone dipropionate ointment (Diprosone) and calcipotriol ointment (Daivonex) in patients with psoriasis vulgaris; 1106 patients were randomized to twice daily double-blind treatment with combination, betamethasone dipropionate or calcipotriol for 4 weeks. Patients then received twice daily calcipotriol, unblinded, for a further 4 weeks. Mean percentage change in PASI at end of the double-blind phase was -74.4 (combination group), -61.3 (betamethasone group) and -55.3 (calcipotriol group). Mean difference (95% Cl) combination-betamethasone was -13.1 (-16.9 to -9.3, p < 0.001) and for combination-calcipotriol -19.0 (-22.8 to -15.2, p <0.001). The differences in PASI were also statistically significant after 1 week. In the double-blind phase, 8.1% of patients (combination) reported lesional/ perilesional adverse reactions compared to 4.7% (betamethasone) and 12.0% (calcipotriol). In the combination group, mean PASI at the end of the double-blind phase was 2.5, and at end of the unblinded phase 3.6, compared with 3.9 and 4.1 (betamethasone) and 4.4 and 3.7 (calcipotriol). Calcipotriol/betamethasone combination is more effective and has a more rapid onset of action than either active constituent used alone, and is well tolerated. It is safe to transfer patients from combination to calcipotriol, with maintenance of clinical effect.

Our data show that clinical improvement of psoriasis following sun exposure is preceded by a rapid reduction in local and systemic inflammatory markers, strongly suggesting that immune modulation mediated the observed clinical effect. We cannot completely rule out that other mechanisms, such as stress reduction, may contribute, but it is extensively documented that UV irradiation is a potent inducer of immunosuppression and we therefore conclude that the observed effect was primarily due to sun exposure.

A 3-month motivational interviewing intervention following CHT had positive overall effects on disease severity, self-efficacy, psoriasis knowledge and health behaviour change. This approach has the potential to be an important complement to medical management, self-management and education in patients with psoriasis.

The results imply that there is no significant difference in transdermal penetration of ALA and MAL in tumour tissue. Detectable levels of drug were not obtained in almost 50% of the lesions where catheters were situated 1-1.9 mm in the lesion. Curettage was not found to affect the interstitial concentration, indicating that penetration of drug indeed might be a problem when treating BCCs thicker than 1 mm.