Expansion
Keloid grows beyond the wound; hypertrophic stays within it
Expansion
| Hypertrophic | Keloid | |
|---|---|---|
| Extent | Within the wound margins | Beyond the wound margins |
| Onset | Weeks | Months, and continues to grow |
| Regression | Often regresses with time | Does not regress |
| Site | Across flexor surfaces, high tension areas | Sternum, shoulder, earlobe, jaw |
| Recurrence after excision | Low | High |
| Ancestry | Any | Commoner in darker skin |
| Collagen | Type III, parallel | Type I and III, disorganised nodules |
“Hypertrophic stays home; keloid trespasses.”
Both result from excess collagen deposition with reduced degradation during the remodelling phase, and both are commoner in wounds under tension, in younger patients and after burns.
Treatment: silicone sheets or gel, intralesional corticosteroid, pressure therapy, and cryotherapy. Excision alone recurs in keloid and often produces a larger lesion, so it is combined with steroid injection or radiotherapy.
A contracture is different again: shortening of a scar across a joint causing loss of movement, from myofibroblast mediated wound contraction, and it is the reason burns across joints are grafted early.