Keloids Flashcards
What is a keloid scar?
An abnormal proliferation of scar tissue that forms at the site of injury, rises above the skin level and projects beyond original wound margins + does not regress.
Pathophysiology
In normal wound healing there is apoptosis and remodelling of ECM to find a balance in wound healing.
During keloid there is a prolonged inflammatory phase. This leads to increased fibroblast activity and increased deposition of ECM.
Risk factors
Ethnicity (most common in Black and Asian populations)
Age - High incidence in 20-30yrs
Burns carry the highest risk of leaving keloid scars
Anatomical site - most common on ear lobe, shoulders and sternal notch
Previous keloid formation
Clinical features
Usually do not normally cause many other symptoms
A small proportion of patients may experience pain, itching or burning in the scar tissue.
They are raised above the skin around them and can take on the apperance of a dome-shape.
They extend beyond the original wound marging.
They can often be shiny and hairless.
Early lesions are often erythematous before becoming brownish and red.
They then turn pale as they age.
What scale is used to quantify features of any scar, including keloids.
Vancouver scar scale
Explain vancouver scar scale.
It is particularly useful in monitoring the effectiveness of treatment.
It take pigmentation, vascularity, pliability and height in account.
Dx
Hypertrophic scars
Dermatofibroma
Dermatofibrosarcoma protuberans
How do hypertrophic scars and keloid scars differ?
Hypertrophic remain confined to the wound margins
Hypertrophic regress over a period of time where keloid dont
Hypertrophic improves with surgical intervention, keloids dont
There is no association with skin colour in hypertrophic scars
Hypertrophic develop soon after injury where it may take months for keloids
Hypertrophic do not form spontaneously
Hypertrophic develop in wound locations under high tension, like shoulders, neck, knees and ankles.
Investigations
Clinical findings
Biopsy of a lesion is very rarely required.
Why is surgical excision of keloids rarely performed?
Recurrence rates between 40-100%
Non-surgical management
Intralesional steroids most widely used (inhibits the fibroblst glucocorticoid receptors)
Silicone gel (wrapped around keloid scar for at least 12h a day)
Radiation therapy (risk of malignancy)
