Question
All are true about Scar shown in Photograph EXCEPT
A. Scar tissue extends beyond boundary of original incision or wound
B. Excess collagen
C. Hypervascularity
D. Improve spontaneously with time
Show Answer
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Correct Answer » D Explanation |
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Ans:D. lmprove spontaneously with time
(Photograph: Keloid scar)
Keloid
- It is an abnormal proliferation of scar tissue that forms at the site of cutaneous injury (eg, on the site of a surgical incision or trauma); it does not regress and grows beyond the original margins of the scar. Keloids should not be confused with hypertrophic scars, which are raised scars that do not grow beyond the boundaries of the original wound and may reduce over time.
- Keloids are benign dermal fibroproliferative tumors with no malignant potential.
- The frequency of keloid occurrence in persons with highly pigmented skin is 15 times higher than in persons with less pigmented skin.
Sites most affected:
- Wounds on the anterior chest, shoulders, flexor surfaces of the extremities (eg, deltoid region), and anterior neck and wounds that cross skin tension lines are more susceptible to abnormal scar formation.
Risk factors:
- The most important risk factor for the development of abnormal scars such as keloids is a wound healing by secondary intention, especially if healing time is greater than 3 weeks. Wounds subjected to a prolonged inflammation, whether due to a foreign body, infection, burn, or inadequate wound closure, are at risk of abnormal scar formation. Areas of chronic inflammation, such as an earring site or a site of repeated trauma, are also more likely to develop keloids.
Pathology:
- The collagen fibrils in keloids are more irregular, abnormally thick, and have unidirectional fibers arranged in a highly stressed orientation.Type III collagen, chondroitin 4-sulfate, and glycosaminoglycan content are higher in keloids than in both hypertrophic and normal scars. Collagen cross-linking is greater in normal scars, while keloids have immature cross-links that do not form normal scar stability.
Histology:
- Keloids have a normal epidermal layer; abundant vasculature; increased mesenchymal density, as manifested by a thickened dermis; and increased inflammatory-cell infiltrate when compared with normal scar tissue.
- 1) the presence of keloidal hyalinized collagen, 2) a tonguelike advancing edge underneath normal-appearing epidermis and papillary dermis, 3) horizontal cellular fibrous bands in the upper reticular dermis, and 4) prominent fascialike fibrous bands.
Treatment:
- Occlusive dressings
- Compression
- Steroid injection
- Excisional Surgery
- Radiation
- Laser therapy
- Interferon therapy
- 5-Fluorouracil