Experience with photodynamic therapy in Hailey-Hailey disease.

Hailey-Hailey disease (HHD) is a rare genodermatosis that is often difficult to treat. This paper reports three patients with HHD treated with one session of photodynamic therapy (PDT) using topical methyl aminolevulinic acid applied under occlusion for 3 hours and red light at 37 J/cm2 for 7.5 minutes. Our results are not successful: all of the patients suffered discomfort during the 3-4 weeks following PDT and only one patient experienced clinical improvement. None of the patients would like to repeat the treatment. PDT is at an exploratory stage; further studies are necessary to determine whether PDT is useful in the treatment of HHD.