What is the difference
between hypertrophic scar and
keloid
•
Both excessive fibrous tissue responses
to healing
• Hypertrophic
scar is confined to site of original injury, is not
progressive beyond 6
months and frequent in children. When a hypertrophic scar is
excised it rarey
recurs.
• Hypertrophic scar is a
result of a problem with
injury – eg burn wound, infected wound, skin sutured under
tension or across
Langer’s lines
• Keloid
extends beyond the boundary of original injury, continues to
grow even years
after injury, rare before puberty and will recur after excision.
• Keloid is result of
genetic and racial
predisposition (dark skin) in characteristic place (sternum)
What is the management
of keloid or hypertrophic
scaringg
•
Prevention:
Incision orientation, avoid tension, avoid infection
•
Obseravtion – never excise within first
6 months as spontaneous
regression may occur in hypertophic scarring
•
Conservative – triamcinolone
injection (long-acting
synthetic corticosteroid),
intra-lesion 5-FU, pulsed dye
laser, XRT, pressure
•
Surgery –
Excision alone, avoiding risk
factors from previous surgery
and changing orientation of wound (Z plasty). Also combined with
post-op
conservative measures - excision combined with pre-, post- or
intra-operative
steroid injection, XRT after excision substantially reduces risk
of recurrence.
What is keratoacanthoma
• Low
grade malignancy of skin originating in pilosebaceous glands
which resembles
SCC.
•
Once considered
benign lesion that resembled malignancy, it is now recognized as
an abortive
malignant process.
• Grows
rapidly over a few weeks and resolves rapidly over a few months
leaving a
residual scar.
•
Central
ulceration or keratin plug
What is the treatment
for KA
•
Surgical excision with margin of 3-5mm.
•
Mohs micrographic
surgery for recurrent lesions or lesions in cosmetically
sensitive areas.
•
XRT can be used
in large tumours where excison will be difficult or disfiguring.
•
Medical
treatments are considered for patients where the diagnosis is
clear where there
are multiple tumours which are inoperable because of location or
medical
condition of patient.