Lac resin, also known as shellac, is a natural resin secreted by the lac insect (Kerria lacca). Its use in the treatment of abscesses is rooted primarily in traditional medicine systems, particularly in Ayurveda and Unani medicine. In these traditions, lac resin has been included in medicinal formulations for its purported antimicrobial, wound-healing, and astringent properties. Historical texts reference lac or its preparations being applied topically to support the healing of wounds, ulcers, and abscesses, with the belief that it can promote the drying and resolution of pus-filled lesions.

However, the scientific evidence supporting the use of lac resin for abscesses is extremely limited. There are no well-conducted clinical trials or robust pharmacological studies specifically examining its efficacy for abscess treatment. The available data are largely anecdotal or extrapolated from its general antimicrobial activity observed in vitro. As such, the evidence for its effectiveness is primarily traditional, with a low rating (1 out of 5) due to the lack of rigorous scientific validation. Modern medical practice does not recognize lac resin as a standard or evidence-based treatment for abscesses.