Photodynamic therapy of sebaceous hyperplasia with topical 5-aminolaevulinic acid and slide projector

Sir, Sebaceous hyperplasia (SH) is a manifestation of photoageing, and can be a cosmetic concern in elderly persons. However, SH has not been a major object for treatment, probably because no satisfactory methods have been developed. Photodynamic therapy (PDT) with the combined use of 5‐aminolaevulinic acid (ALA) and visible light is now successfully used in the treatment of superficial nonmelanoma skin cancers including actinic keratosis, Bowen's disease and superficial basal cell carcinoma.1, 2 The advantages of this PDT modality include the absence of prolonged systemic photosensitivity and the preferential accumulation of the intermediate metabolite protoporphyrin IX (PpIX) in tumour cells after topical application of ALA. Topically applied ALA is rapidly cleared from the tissue and therefore causes only a brief period of photosensitivity. It was recently demonstrated that PpIX accumulates not only in the malignant cell but also in the pilosebaceous units,3, 4 which can be target tissues in ALA‐PDT. Thus, we tried PDT for the treatment of SH.