RESUMO
This study was done on 12 patients with post-burn alopecia of the scalp. Tissue expander techniques were performed on those patients using the balloon expander. The expanders were inflated weekly with saline under the hair bearing area, in the subgaleal and the supra- periosteal plane. The aim of this work was to study the tissue response around the expanders, which is called the formed capsule. The histopathological study showed that the capsule is formed of four zones inner cellular zone, central zone of fibrous tissue and elastic fibers, transitional zone of hyalinized fibrous tissue, and outer zone of newly formed blood vessels. Every zone has its clinical significance, particularly the inner one, which contains inflammatory cellular reaction, in playing a role in infection resistance. The outer one, the vascular zone, adds blood supply to the overlying hair bearing area of the scalp