ALA-PDT is capable of clinically improving acne. An alternative mode of action for ALA-PDT other than direct damage to sebaceous glands or photodynamic killing of P. acnes is suggested from the results of this study.

No abstract

Hypercornification is an early feature of acne and precedes inflammation. It is associated with ductal hyperproliferation and there are many controlling factors such as androgens, retinoids and cytokines. Cycling of normal follicles and of comedones may explain the natural resolution of comedones and, in the longer term, resolution of the disease itself. There is a need to tailor treatment according to comedonal type. Suboptimal therapy can often result from inappropriate assessments of comedones, especially microcomedones, missed comedones, sandpaper comedones, submarine comedones and macrocomedones. Macrocomedones can produce devastating acne flares, particularly if patients are inappropriately prescribed oral isotretinoin. Gentle cautery under topical local anaesthesia is a useful therapy in the treatment of such lesions. The newer retinoids and new formulations of all-trans-retinoic acid show a better benefit/risk ratio. Evidence-based studies are required to allow adequate comparisons.

The success reported for the treatment of superficial skin carcinomas by photodynamic therapy with topical application of the photosensitizer precursor 5-aminolevulinic acid has therapeutic implications for the treatment of other skin disorders. This paper describes the accumulation of the photosensitizing agent protoporphyrin IX in areas of plaque psoriasis by monitoring of the fluorescence emission induced by low-intensity laser excitation at 488 nm. We present results from 15 patients with a total of 42 plaques and show that the characteristic fluorescence emission of protoporphyrin IX increases in intensity within the 6-h period following application of 5-ami-nolevulinic acid, suggesting that there is a potential for superficial photodynamic therapy. The rate of increase and maximum intensity of fluorescence emission was not directly related to the applied quantity of the precursor. The variability of the fluorescence intensity was as great between plaques at different sites on the same patient as between different patients. Also, the effect of plaque occlusion following application appeared insignificant. Although there was only limited enhancement of emission from areas of skin surrounding the plaque, a significant buildup of sensitizer was detected after several days in some areas of psoriasis that received no application.