The successful treatment of hidradenitis suppurativa (HS) with intralesional photodynamic therapy (IL-PDT) has been previously reported.

The purpose of a new study published in Photodiagnosis and Photodynamic Therapy was to present additional data and patient outcomes for IL-PDT.

This was anobservational retrospective study that recruited 42 patients diagnosed with HS and treated with IL-PDT. Under local or general anesthesia, 5-aminolevulinic acid (5ALA) in gel 2% or solution 1 % was administered into the lesion. Thereafter, the lesion was intralesionally irradiated—1.4 W, fluence 168 J/cm2, with the tip of a 0.4-mm thick optical fiber connected to a continuous 630-nm diode laser—two hours later. 

Overall, 117 lesions – 28 nodules and 89 fistulae, were treated. It was noted thatat 3 months, 22.2% of the lesionshad resolved,62.4%had improved in size or symptoms,whereas, 15.4% experienced no change. The most frequent side effects were skin burns – in 45.3% lesions, and abscess formation – in 6.8% lesions. Significant variables for no benefit were – a higher International Hidradenitis Suppurativa (IHS4) score, active smoking, and gluteal and inguinal location.

The results depicted that IL-PDT was useful in most patients. Early intervention in patients with a lower inflammatory burden was advocated.

Source: Photodiagnosis and Photodynamic Therapy. 2021 May 14;34:102339. doi:10.1016/j.pdpdt.2021.102339