Photodynamic therapy for Hidradenitis Suppurativa/acne inversa: Case report

•PDT can be applied in treatment of Hidradenitis suppurativa/acne inversa (HS/AI).•Optical fiber therapy can be applied in treatment of lesions at sinus tracts.•More PDT treatments contributes to a good clinical efficacy. Hidradenitis suppurativa/acne inversa (HS/AI) is a type of chronic suppurative inflammatory reaction of the hair follicles characterized by recurrent dermal abscesses, sinus tracts and scars. So far, there has not been any prospective study proving the efficacy and safety of photodynamic therapy for the disease. In this report, one case of HS/AI achieved resolution of skin lesions, ulcer healing and disappearance of symptoms after nine treatments with 5-aminolevulinic acid photodynamic therapy (ALA-PDT).