Axillary defect coverage is often challenging after radical excision of chronic inflammatory skin lesions, such as complicated epidermoid cysts and hidradenitis suppurativa. This retrospective case series aims to demonstrate our experience with axillary reconstruction using the modified keystone perforator island flap (KPIF) technique, emphasizing its tension-reducing effects. All patients who presented for axillary reconstruction after radical excision of chronic inflammatory skin lesions between May 2019 and December 2020 were identified using the medical record database. Eleven patients ranging in age from 17 to 71 years underwent modified KPIF axillary reconstruction. Four types of modifications (modified type II KPIF, omega variation closure, Sydney melanoma unit modification, and hemi-KPIF) were used. All defects (size range, 2.5 × 3 cm2 to 8 × 13 cm2) were successfully covered using these modified KPIF techniques. All flaps (size range, 3.5 × 3.5 cm2 to 11 × 30 cm2) fully survived without complications. All patients exhibited favorable functional outcomes, and no cases of recurrence or limitations in joint range of motion were observed during the follow-up period (range, 4-5 months). Modified KPIF techniques may represent a reliable, effective alternative reconstructive modality for managing axillary defects.