Disappointing results and low tolerability of photodynamic therapy with topical 5-aminolaevulinic acid in psoriasis. A randomized, double-blind phase I/II study.

BACKGROUND: Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials. OBJECTIVE: A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis. METHODS: In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm(2) and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI). RESULTS: The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation. CONCLUSION: Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile.

Topical aminolaevulinic acid-based photodynamic therapy as a treatment option for psoriasis? Results of a randomized, observer-blinded study.

BACKGROUND: Topical aminolaevulinic acid-based photodynamic therapy (ALA-PDT) has recently been tried in small open studies for several inflammatory dermatoses including psoriasis. OBJECTIVES: The purpose of this randomized, within patient comparison study was to investigate whether topical ALA-based PDT using a range of light doses can induce a satisfactory response in localized psoriasis. PATIENTS AND METHODS: Twenty-nine patients with chronic plaque type psoriasis were enrolled in the study. After keratolytic pretreatment three psoriatic plaques in each patient were randomly allocated to PDT with 1% ALA and a light dose of 5 J cm(-2), 10 J cm(-2) or 20 J cm(-2), respectively. Treatment was performed twice weekly until complete clearance or for a maximum of 12 irradiations. As a measure of clinical response the psoriasis severity index (PSI) of the three target plaques was assessed separately by an observer blinded to the treatment at baseline, before each PDT treatment and 3-4 days after the last irradiation. RESULTS: Eight patients withdrew prematurely from the study. Keratolytic pretreatment alone reduced the baseline PSI in all three dose groups by about 25%. Subsequent PDT with 20 J cm(-2) resulted in a final reduction of PSI by 59%, PDT with the lower doses of 10 J cm(-2) and 5 J cm(-2) decreased the baseline PSI by 46% and 49%, respectively. The difference in clinical efficacy between 20 J cm(-2) and 10 J cm(-2) or 5 J cm(-2) was statistically significant (P = 0.003; P = 0.02), whereas no difference was found between 10 J cm(-2) and 5 J cm(-2) (P = 0.4). All patients reported some degree of PDT-induced stinging or burning during irradiation. CONCLUSIONS: The unsatisfactory clinical response and frequent occurrence of pain during and after irradiation renders topical ALA-based PDT an inadequate treatment option for psoriasis.

Novel pharmacological approaches in the treatment of psoriasis.

Progress in the understanding of psoriasis as a T-cell mediated inflammatory disease has led to the development of new immunomodulatory therapies. Currently the main focus is on the so-called biologics (or biological agents), including fusion proteins, monoclonal antibodies, cytokines and selective receptors. They mainly target single steps in the complex cascade of humoral and cellular inflammatory immuno-mechanisms that finally lead to the accelerated growth of epidermal and vascular cells in the psoriatic lesions. The most promising and advanced biological agents are discussed along with their influence on the critical pathophysiological steps in psoriasis, including depletion of T cells, blockade of initial T-cell activation and T-cell receptor (TCR) stimulation, blockade of costimulatory signals and T-cell proliferative signals as well as restoration of the T helper type 1 (Th1)/Th2 balance by diminishing type 1 cytokines and administration of type 2 cytokines. In addition to the biological agents, further development of 'classical' dermatological therapies, such as retinoids, or the discovery of new indications for non-dermatological agents contribute to the novel pharmacological approaches in the treatment of psoriasis.

["Smoldering systemic mastocytosis. "Successful therapy with cladribine]. / "Smouldering systemic mastocytosis". Erfolgreiche Therapie mit Cladribin.

Mastocytoses are a heterogenous group of diseases characterized by proliferation and accumulation of mast cells in the skin and other organs. They are subdivided into cutaneous mastocytoses; systemic forms, which may appear with or without skin lesions; mast cell sarcomas and extracutaneous, localized, benign mastocytomas. Systemic mastocytoses apart from the skin mainly involve bone marrow, gastrointestinal tract, bones, lymph nodes, spleen and liver. Whereas indolent forms of systemic mastocytosis are mainly treated with antihistamines, glucocorticosteroids and PUVA therapy, the more aggressive forms, including mast cell leukemia, often require cytostatic chemotherapy. A 53-year old patient with beginning "smoldering systemic mastocytosis" failed to respond to high-dose systemic glucocorticosteroids and interferon-alpha. Treatment with cladribine led to an impressive improvement of skin lesions, a significant decrease in tryptase serum levels and stabilization of bone marrow infiltrates.