Jan C. Simon

treatment of chronic palmoplantar eczema with local bath-PUVA therapy

BACKGROUNDnSystemic PUVA therapy may be useful in the treatment of chronic palmoplantar eczema. Topical PUVA-paint avoids some of the unwanted side effects of systemic psoralens and has been used successfully in the treatment of palmoplantar eczema and psoriasis. However, few data are available on the effectiveness of local bath-PUVA therapy in palmoplantar eczema.nnnOBJECTIVEnOur purpose was to assess the effectiveness of local bath-PUVA therapy in 28 patients with chronic palmar or plantar eczema or both who were resistant to conventional topical treatment.nnnMETHODSnAfter fungal or bacterial infection had been excluded in all patients, hands or feet or both were soaked for 15 minutes in warm water containing 1 mg/L 8-methoxypsoralen. Immediately after, the skin was irradiated with increasing doses of UVA, starting with 0.5 J/cm2. PUVA-bath therapy was performed 4 times a week up to a total of 25 treatments. No additional therapy was allowed except emollients.nnnRESULTSnExcellent or good effects were achieved in 93% of the patients with dyshidrotic and in 86% of the patients with hyperkeratotic eczema. In the patients with dyshidrotic eczema, the cumulative doses and the highest single doses of UVA were lower than those in the patients with hyperkeratotic eczema (21.4 vs 27.9 J/cm2 and 2.4 vs 3.0 J/cm2 of UVA), but this was not statistically significant. No phototoxic reactions were observed.nnnCONCLUSIONnLocal bath-PUVA therapy is of value in the management of chronic palmoplantar eczema resistant to standard modes of topical treatment. Compared with topical PUVA-paint, local bath-PUVA therapy has several advantages, particularly the absence of phototoxic reactions, severe hyperpigmentation, and protracted photosensitivity.

Phototesting in bath-PUVA : marked reduction of 8-methoxypsoralen (8-MOP) activity within one hour after an 8-MOP bath

It is not known how long after 8‐MOP bath‐PUVA administration erythema can be induced. Therefore, after determination of dose‐dependence and kinetics of bath‐PUVA erythema, we investigated the development of erythema using an erythematogenic UVA‐dose (3 J/cm2) in time course experiments. Our results show that there is a loss of biological 8‐MOP activity already 1 h after 8‐MOP bath. This has important consequences for clinical practice with bath‐PUVA, concerning the optimum time interval between the 8‐MOP bath and irradiation as well as the persistence of photosensitivity in normal skin after bath‐PUVA.

In vitro and in vivo activation of hypericin with the incoherent light source PDT 1200 SOA (520–750 nm) and with solar simulated radiation (290–2500 nm)

The photodynamic active plant pigment hypericin is a possible new photosensitizer for photodynamic therapy. Hypericin shows absorption maxima in the ultraviolet (330 nm) and visible light range (550 and 588 nm). The present study compared the photoactivation of hypericin with the incoherent light source PDT 1200 SOA (520–750 nm) to that with a 1000 watt solar simulator (290–2500 nm). Hypericin displayed dose and time dependent phototoxic effects in the keratinocyte cell line HaCaT in vitro and after intracutaneous in vivo application with both light sources. In vivo, delayed (48 h) photosensitivity in hypericin‐sensitized skin was observed. With intracutaneous application of 100 ng/ml hypericin, no phototoxic reaction could be produced. The PDT 1200 SOA was about four times more effective in vitro and about ten times more effective in vivo when compared to the solar simulator. Since the PDT 1200 SOA allows homogenous irradiation of large areas, we conclude that the PDT 1200 SOA is an effective and convenient light source for in vitro and in vivo studies using hypericin.