“…Systemic corticosteroids, cyclosporin, methotrexate, acitretin, or alitretinoin may be considered for generalized HHD ( Sárdy and Ruzicka, 2014 ; Ben Lagha et al, 2020 ); however, long-term use is not recommended because of serious side effects. Multiple new treatments have been demonstrated to be effective in some refractory cases of HHD in recent years, including botulinum toxin, naltrexone, dupilumab, apremilast, photodynamic therapy, common or fractional CO 2 laser, 595-nm pulsed dye laser, and electron beam radiotherapy ( Di Altobrando et al, 2020 ; Michael et al, 2020 ; Alzahrani et al, 2021 ; Dulmage et al, 2021 ; Zhang et al, 2021 ). Long-term improvement was observed in some patients treated with various laser ablation or electron beam radiotherapy ( Leung et al, 2018 ).…”