| Cryosurgery | Curettage
| Dermabrasion | Electrosurgery
| Patch tests | Phototests
excision punch elevation and punch grafting | RAST
tests | Shave excision | Simple excision and closure
| Skin biopsies | Skin
A comedone (blackhead
or whitehead) extractor can be used to extract comedones
and milia. The instrument has a central opening which is placed
over the opening of the blackhead (open comedo) and then pressed
gently downwards to extrude the contents. Whiteheads or closed
comedones may be punctured with a sterile needle or number 11
scalpel blade beforehand to facilitate extraction.
in Greek means cold) which means cold surgery uses cold to destroy
tissue. The most common agent used is liquid nitrogen but carbon
dioxide snow and nitrous oxide are sometimes also used. Cotton-tipped
applicators or a spray nozzles can be used to deliver liquid
nitrogen (which has a temperature of -196 deg C). At such low
temperatures, ice crystals form inside the cells rupturing the
cell membrane and disintegrating the cell. There is a stinging,
burning pain which peaks about 2 minutes afterwards. The area
swells and a blister, which may not be visible, forms 3 - 6 hours
later. The blister dries to form a scab in 2 - 3 days and the
scab dislodges after 2 - 3 weeks. Temporary hypopigmentation
may occur. The treatment does not require anaesthesia. Liquid
nitrogen cryosurgery is useful for treating superficial abnormalities
such as acrochordons (papillomas
or skin tags), seborrhoeic
keratoses (age warts), actinic
lentigines (age spots), viral warts
and some basal cell and
squamous cell cancers.
The curette is a spoon
shaped instrument with a sharp edge. After cleaning the area
with alcohol and giving a local anaesthetic injection, the edge
of the curette is applied to the skin growth which is then scooped
in a quick downward action. Bleeding is stopped by direct pressure,
electrosurgery or with the application
of stryptic (clot-inducing solution). Curettage can be used to
remove viral warts, milia
(tiny whitehead-like cysts), seborrhoeic
keratoses (age warts) and some basal
cell and squamous
Dermabrasion or surgical
skin planing removes the epidermis and superficial dermis and
helps to "refinish" the skin. Regeneration occurs from
remaining structures such as hair follicles, sebaceous glands
and sweat glands. The equipment, called a dermabrader, is a rapidly
rotating abrasive device which may be gas or electricity driven.
It is used to remove or "sand away" the upper layers
of the skin so that the new skin that grows over is smoother
in appearance. Dermaplaning is a similar technique in which a
dermatome (an instrument that works like a electric razor) is
used to "skim" off layers of skin. Dermabrasion is
especially good for acne scars (but not the deep ice-pick scars
which usually require prior punch
excision) and wrinkles around the mouth. The benefits lasts
2 - 10 years.
- Improve mild to moderate
wrinkles, especially those around the mouth
- Improve mild to moderate
- Remove solar
keratoses (precancerous growths)
- Improve scars from
trauma, surgery, chicken pox or acne vulgaris
- Improve rhinophyma
(bulbous enlargement of the nose)
Depending on the size of the area being treated, general anaesthesia
or local anaesthesia (including nerve blocks) with or without
intravenous (IV) sedation may be used.
There is much splattering of blood and tissue during the procedure
so protective gowns and goggles must be worn by the patient and
the physician and his assistants. The area to be treated is painted
with gentian violet. Then 3 x 3 cm square areas of skin are sequentially
frozen and abraded to the required depth. An antibiotic ointment
or vaseline may be applied or the doctor may apply a dressing
for the first 1 - 2 days. You may be admitted to hospital for
1 - 2 days if you are having full-face dermabrasion. Otherwise
you will need someone to drive you home and to look after you
for the first 1 - 2 days. Dermabrasion takes several minutes
to 1 1/2 hours to perform.
course and after-care
- There is swelling
which may shut the eyes and mouth and oozing of yellowish fluid
from under the dressing. Talking and eating may be difficult
and you may need to take a liquid diet.
- The swelling may be
reduced by sleeping in a sitting or semi-reclining position.
- If a dressing is used,
it is normally removed after 1 - 2 days to reveal red, raw skin.
- Care of the wound
involves using wet compresses
or frequent soaks several times a day followed by application
of an antibiotic ointment or vaseline.
- Crusts should be softened
and gently (not forcibly) removed, whenever possible. The crusts
are usually shed after 7 - 10 days.
- There may be slight
itching as the new skin grows which can be relieved with antihistamines or a
mild steroid cream
from the doctor.
- Sleeping pills and
simple painkillers such as aracetemol may be taken, if necessary.
- Normal activity can
be resumed after the crusts have shed.
- The skin remains pink
for 6 weeks to 6 months and can be camouflaged with make-up.
- Sunscreens should be used when the skin
is still red and should be continued indefinitely.
- Bacterial infection
are rare if the doctors instructions are carried out properly.
- Herpes labialis may recur after dermabrasion. This can
be prevented by taking an anti-herpes drug such as acyclovir
or famcyclovir 1 day before and continued for a total of 7 -
- Milia or tiny "whiteheads"
may develop. They can be extracted with a number 11 scalpel blade.
- Redness may persist
for 6 weeks to 6 months and can be concealed with green cosmetics.
- Enlarged pores may
occur temporarily but usually settles when the swelling subsides.
- Hypopigmentation (reduced
pigmentation) is usually temporary. Permanent hypopigmentation
can occur if dermabrasion is carried out too deep, especially
in darker skin types (phototypes
IV and above). The lightened skin also loses its ability to tan.
- Blotchy hyperpigmentation
(increased pigmentation) may develop especially in phototypes
III and IV skins but is usually temporary lasting 3 - 4 weeks.
It can be treated with hydroquinone lightening creams and regular
application of sunscreens (see melasma).
- Scarring and keloids
may rarely develop. The skin should improve day by day but if
it becomes red, raised and itchy after it has healed, consult
the doctor. It may indicate the development of a keloid. Isotretinoin treatment has
also been reported to increase the risk of scarring. This is
why doctors wait 12 - 18 months after stopping isotretinoin before
electricity to destroy tissue. The electrosurgical unit has a
transformer which increases the voltage of the current an oscillator
to increase the frequency. The current is delivered to the skin
via an electrode. On the skin, it meets resistance and heat is
generated which literally cooks the tissue.
Electrosurgery can be used to destroy warts,
small growths on the skin such as acrochordons
(skin tags), syringomas, seborrhoeic keratoses
(age warts), pyogenic granulomas
and telangiectasias and
cherry angiomas. Local
anaesthesia is normally used unless the treatment area is very
small. Using special electrodes known as epilation needles, electrosurgery
can also be used to remove unwanted hairs on the upper lip and
chin. This is known as electrosurgical epilation (see hirsutism).
Tell the doctor if you are wearing a pacemaker (a device implanted
in the chest to regulate the heartbeat) because electrosurgical
devices may cause damage to them.
The patch test is used
to identify the cause of allergic contact dermatitis. It involves
applying a microporous tape with multiple aluminium chambers
(called Finn chambers) containing the test chemicals to the back.
After 48 hours, the tape is removed and the skin is examined
20 minutes later for a reaction. A positive reaction comprises
of redness, swelling and even blistering. A second reading is
carried out at 96 hours to detect delayed reactions. Patch tests
are normally done only after the dermatitis is less acute, otherwise
ambiguous results may be obtained.
Patch tests should
be interpreted by a dermatologist because it requires skill to
distinguish an allergic reaction from an irritant one. In the
standard patch test, 24 or more common allergy causing chemicals
are used. Additional chemicals are added depending on the history
of exposure and the type of dermatitis. Once the cause has been
identified, further exposure to the allergen must be avoided
in order to avoid a recurrence. Patch tests only confirm or exclude
an allergy to the substances tested. A negative test does not
exclude an allergy because the culprit may not have been included
in the test. It takes an experienced doctor and careful history
taking to determine which chemicals should be added.
on image for larger view
Photopatch tests are a special type of patch test used to detect
allergy to chemicals that occur only in the presence of sunlight.
It is done like the standard patch test above except that two
sets of chemicals are used and one set is exposed to ultraviolet
A light (UVA). It is used to diagnose photoallergic
contact dermatitis, a type of allergic contact dermatitis
that only occurs in the presence of light.
Phototests are used
to detect photosensitivity
(sensitivity to sunlight). It involves the use of an equipment
called a monochromator which produces light of
different wavelengths. One centimetre areas of skin on the back
are exposed to different doses of light or different wavelengths
and the test areas are examined 24 hours later for a reaction.
shining the test areas daily for 3 days to provoke a reaction.
They are used for the diagnosis of polymorphic
light eruption (PMLE).
Photopatch tests are
a special type of patch test used to detect allergy to chemicals
that occur only in the presence of sunlight (photocontact
dermatitis). It is done like the standard patch test above
except that two sets of chemicals are used and one set that the
test areas are exposed to ultraviolet A light (UVA).
PUNCH EXCISION, PUNCH ELEVATION
AND PUNCH GRAFTING
These procedures are
often used to treat deep ice-pick acne scars and involve the
use of the biopsy punch. This instrument which works like
a cookie-cutter is used to remove the core of scarred skin or
a small skin abnormality. In a simple punch excision, the edges
of the wound are simply stitched together. In punch grafting,
a skin graft is taken from a hidden site, usually the back of
the ear with the same instrument and transferred to the wound.
Punch elevation is another modification that may be performed
as a prelude to chemical
peels, dermabrasion and laser
resurfacing. In punch elevation, the core of skin is not
discarded but is elevated from the underlying fat and held in
place with a special tape or a stitch.
RAST is an acronym
test. It detects IgE antibodies in the blood to
specific antigens (allergy causing substances). RAST can detect
immediate allergic reactions to house dust, house dust mites
and some food products and drugs. It gives similar information
to skin tests.
In this method, a razor
blade or scalpel blade is used to shave the raised abnormality
flush with the skin. It is also done under local anaesthesia
and does not require any suturing. It is often used for removing
raised moles and seborrhoeic
keratoses (age warts).
SIMPLE EXCISION AND CLOSURE
This is probably the
most common procedure done to remove small abnormalities. A local
anaesthetic injection is given beforehand. An elliptical incision
is made around the lesion and the edges are sutured together.
The incision is aligned in the direction of the normal skin lines
so that the resultant scar will not be very obvious.
This is one of the
most common procedures done in dermatology. It involves removing
a piece of skin for histopathologic examination using a light
microscope, an immunofluorescence microscope or electron microscope.
The tissue may sometimes also be sent for culture (growth) of
fungi, bacteria or virus.
Skin tests, like the
RAST, are used to identify the cause
of immediate (IgE mediated) allergic reactions, ie., reactions
that occur within minutes of exposure. Immediate allergic reactions
may occur in the form of urticaria, anaphylaxis,
angioedema or contact
urticaria. The culprit may be a substance that is inhaled
(eg., house dust, house dust mite and pollens), ingested (eg.,
drug or food item), injected into the body (eg., x-ray contrast
media, vaccines, drugs or insect bites and stings) or that has
come into contact with the skin (eg., contact
urticaria). There are two types of skin tests:
- Prick (scratch)
the test reagents are placed on the forearm skin and a lancet
is used to prick and raise the skin such that a small amount
of the test solution enters the skin. When the suspected cause
is not available in the form of a test solution, the substance
itself is placed on the skin after it has been scratched.
- Intradermal (intracutaneous)
the test reagent is injected into the skin.
The test sites are
examined about 20 minutes later for a reaction. The severity
of the reaction is then compared with controls (saline and histamine)
to determine whether the reaction is a true allergic reaction
Some individuals are
so allergic such that they may develop a very severe reaction.
These tests should therefore be performed in centres that have
access to full resuscitation facilities.