Hypertrophic scars are defined as benign fibrous growths that occur after trauma or wounding of the skin that involves the deep layers of the dermis and express high levels of pro-fibrotic cytokines such as IGF-1 and TGF-β1. It’s characterized by deposits of excessive amounts of collagen which gives arise to a raised scar.1,2 One of the main differences between keloid and hypertrophic scars is that keloid have not been reported in patient with oculocutaneous albinism, and they are more frequents in individuals with more darkly pigmented skin. From the facts exposed above, it seems that the melanin-producing melanocytes may play a role in the keloidal response.1 Other difference is that while hypertrophic scars remain in the are of original injury, and they have a tendency toward gradual resolution over time, keloids migrate to adjacent tissue with very active borders, and show a tendency towards regression in the central portion of the lesion.
1Bolognia, J. L., Jorizzo, J. L., & Rapini, R. P. (2007). Dermatology (2a ed.). San Luis, MO, Estados Unidos de América: Mosby.
2Brash, D. E., Goncalves, L. C. P., & Bechara, E. J. H. (2018). Chemiexcitation and its implications for disease. Trends in Molecular Medicine, 24(6), 527–541.
Zhu, Z., Zhang, Y., Ko, H.-S., Martins, P., Saraiva, J., & Hu, Z. (2016). Parsing and reflective printing, bidirectionally. Proceedings of the 2016 ACM SIGPLAN International Conference on Software Language Engineering. New York, NY, USA: ACM.
Zhu, Zhensen, Ding, J., & Tredget, E. E. (2016). The molecular basis of hypertrophic scars. Burns & Trauma, 4(1), 2.
Seaton, M., Hocking, A., & Gibran, N. S. (2015). Porcine models of cutaneous wound healing. ILAR Journal, 56(1), 127–138.
Visscher, M. O., Bailey, J. K., & Hom, D. B. (2014). Scar treatment variations by skin type. Facial Plastic Surgery Clinics of North America, 22(3), 453–462.
Wilgus, T. A., & Wulff, B. C. (2014). The importance of mast cells in dermal scarring. Advances in Wound Care, 3(4), 356–365.
Zhu, Zhensen, Ding, J., Shankowsky, H. A., & Tredget, E. E. (2013). The molecular mechanism of hypertrophic scar. Journal of Cell Communication and Signaling, 7(4), 239–252.
Gauglitz, G. G., Korting, H. C., Pavicic, T., Ruzicka, T., & Jeschke, M. G. (2011). Hypertrophic scarring and keloids: Pathomechanisms and current and emerging treatment strategies. Molecular Medicine (Cambridge, Mass.), 17(1–2), 113–125.
Li, B., & Wang, J. H.-C. (2011). Fibroblasts and myofibroblasts in wound healing: force generation and measurement. Journal of Tissue Viability, 20(4), 108–120.
Singer, A. J., Huang, S. S., Huang, J. S., McClain, S. A., Romanov, A., Rooney, J., & Zimmerman, T. (2009). A novel TGF-beta antagonist speeds reepithelialization and reduces scarring of partial thickness porcine burns. Journal of Burn Care & Research: Official Publication of the American Burn Association, 30(2), 329–334.
Gallant-Behm, C. L., Hildebrand, K. A., & Hart, D. A. (2008). The mast cell stabilizer ketotifen prevents development of excessive skin wound contraction and fibrosis in red Duroc pigs. Wound Repair and Regeneration, 16(2), 226–233.
Lu, L., Saulis, A. S., Liu, W. R., Roy, N. K., Chao, J. D., Ledbetter, S., & Mustoe, T. A. (2005). The temporal effects of anti-TGF-beta1, 2, and 3 monoclonal antibody on wound healing and hypertrophic scar formation. Journal of the American College of Surgeons, 201(3), 391–397.
Beer, T. W., Baldwin, H., West, L., Gallagher, P. J., & Wright, D. H. (1998). Mast cells in pathological and surgical scars. The British Journal of Ophthalmology, 82(6), 691–694.
Alhady, S. M., & Sivanantharajah, K. (1969). Keloids in various races. A review of 175 cases. Plastic and Reconstructive Surgery, 44(6), 564–566.
- The ScarFree Foundation
- Harvard Medical School
- Johns Hopkins Medicine
- University of Chicago Medicine’s Burn and Complex Wound Center
- Tampa General Hospital
- The Model Systems Knowledge Translation Center (MSKTC)
Despite the fact that are some studies in which the females seem to be more affected by the hypertrophic scars, probably reflecting the greater frequency of earlobe piercing among females1, in general, the researchers reach to the conclusion that men and women are similarly affected.2,3
1Kelechi, Uruakpa & Eru, Eru & Udo-Affah, U. (2020). Journal of Biology, Agriculture and Healthcare. International Institute for Science, Technology and Education.
2El Kinani, M., & Duteille, F. (2020). Scar epidemiology and consequences. En Textbook on Scar Management (pp. 45–49). Cham: Springer International Publishing.
3Niessen, F. B., Spauwen, P. H., Schalkwijk, J., & Kon, M. (1999). On the nature of hypertrophic scars and keloids: a review. Plastic and Reconstructive Surgery, 104(5), 1435–1458.
- The more darkly pigmented the skin, the higher the risk is for keloid formation
- Hypertrophic scars are common after burn injuries
- The incidence rate after surgery is around 40 to 94%
- Hypertrophic scars can occur after inflammation from a skin condition, including acne and chickenpox