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The field of cosmetic dermatology has seen an exponential rise in popularity with the advent of less invasive cosmetic procedures and acceptability by the mainstream population. It is important to note that the cosmetic patient visit will differ to that of the medical patient, as in many cases the treatment will be for a normal physiological phenomena - ageing. There are benefits to these cosmetic procedures that extend beyond improvement of the outward appearance due to ageing and numerous studies have shown a positive correlation with increased rate of employment, income, social, and psychological well-being. A word of caution must be made at this point to ensure that these procedures are not being delivered in an attempt to overtreat or change appearance to conform to current fashion ideals and impossibly perfect 'selfie' pictures.
The concept of beauty as a single ideal standard is difficult to determine and features of beauty vary based on age, culture, race, and gender types. There are some features, however, that are standard throughout - we know that symmetrical and average proportions are crucial factors in determining beauty.
Ageing of the skin, as with all organs, is inevitable and occurs from a combination of extrinsic and intrinsic factors. Intrinsic ageing gives the appearance of fine wrinkled skin on a homogenous background and is determined by our genetic skin type. Extrinsic ageing leads to the hallmark signs of dryness, dyspigmentation, telangiectasia, and wrinkling (fine or coarse) and is caused predominantly by ultraviolet light, tobacco smoke, and other forms of non-ionising radiation. It is not just the skin that gives us an aged appearance, it is the concomitant effect of the underlying structures. Bone ageing, which leads to volume and support loss, hypertrophy and atrophy of facial muscle groups, and reduction and lowering of the facial fat pads all play their part in the ageing of the face (Figure 26-1).
As with medical patients, this is the key component to the management of the cosmetic patient. At consultation, you develop an understanding of the patient's concerns and expectations for cosmetic improvement and the motivation behind seeking treatment. It is important to obtain a full medical and psychosocial history, a history of previous cosmetic procedures and satisfaction with them. Notes should be made to determine if there is a medical cause for the cosmetic concern, such as hirsutism, or a psychological concern such as body dysmorphia disorder (BDD). It is important to have a record of the concerns from the initial visit.
Evaluation of the face should be done in the upright position and a note should be made of the Fitzpatrick skin type and texture of the skin. Evidence of photo ageing should be recorded using the Glogau classification (Figure 26-2) and attention should be paid to areas of volume loss, sagging, or atrophy.
It is very important to consider the face as an entire unit. Photographic documentation is more accurate for recording treatment outcomes than handwritten notes.
An unexaggerated discussion of potential interventions, with the benefits and risks (common and serious) and alternatives, can be explained. A treatment plan should be given to the patient to outline the procedures considered. It is advisable to allow the patient some time to consider what you have discussed prior to immediate treatment.
Injectable fillers are the key agents for the management of facial ageing associated with shrinkage of fat pads and their malalignment, they can also be used to improve skin quality and decrease depth of wrinkles. Early injectable fillers were made of collagen however, due to the risk of infection, hypersensitivity, and poor longevity compared with hyaluronic acid (HA) products, they are no longer used. To reduce the risk of complications it is advisable to use a product that has robust safety and results data from controlled clinical trials. It is important that the correct filler should be used for the relevant indication, placed correctly within the soft tissue (Figure 26-3), and that the underlying anatomy is well understood e.g. fillers used for volumising should be used deep only and not too superficially to avoid unsightly blue bump (Tyndall effect).
Temporary fillers are those which are biodegradable and further divided into those which may stimulate collagen and those that are clinically inert.
Hyaluronic acid (HA) fillers dominates the market, as they are reversible, long-lasting, and have low allergenic potential and a robust safety profile for many of the branded products. HA is capable of holding 1000 times its weight in water. The products come in various concentrations, particle size, cross linkage, and some contain anaesthetic product. The safety of HA is further enhanced due to its reversible nature using the enzyme capable of degrading it, hyaluronidase. Hyaluronidase can be used in an emergency where there is vessel occlusion with HA and also where there is inappropriate filler placement, overcorrection, or post-treatment inflammatory nodules.
Polyl-L-lactic acid(PLLA) has significant collagen-stimulating ability. Injections are usually given six weeks apart (course of three injections) and there is a delayed effect to onset. Although uncommon nodule formation is the main adverse reaction associated with PLLA, and in rare cases this can be very large.
Calcium hydroxyapatite(CaHa) is made up of calcium phosphate pearls and was initially used for treating lipoatrophy in patients taking antiretrovirals. This product can induce formation of large permanent nodules.
Permanent fillers such as silicones, polyacrylamide, and polyalkylamide are generally not in use and not recommended within current guidelines due to the severity of adverse reactions, both acute and delayed. It should be remembered that the patient's immunological response to a permanent product may change with time and adverse effects such as large granulomatous reactions may occur. Currently there is no antidote to a permanent filler other than surgery.
Polymethylmethacrylate(PMMA) is a permanent filler that is currently available. It is a combination substance of PMMA beads in a bovine collagen that will remain permanently in the skin, and currently it has a licence for treating acne scars.
There should be thorough understanding of the facial anatomy to reduce the risk of serious complications by inadvertent injection into an artery. Both needles and cannula can be used depending on the specific indication. In some areas only a needle can be used, such as injections to improve skin quality. In other areas the cannula technique can be used, to improve patient safety as there is a reduced risk of penetration into a vessel and resultant embolism. The filler is then injected when it is in the correct plane of tissue in either micro aliquots, or stacked on top of each other or as a fanning technique. The skin should be disinfected and treated as a sterile procedure to avoid infection.
Depending on the desired outcome filler is placed to support the skin on underlying bone, add volume, and fill lines or to used more superficially for improved skin tone and texture. Individual areas can be treated, such as lips (Figure 26-4). Care should be taken to ensure that individually treated areas remain in proportion to the rest of the face.
Adverse reactions and their management
The most serious adverse reactions occur as a consequence of intravascular injection and arterial infarction; abscesses, nodular formation, and immunological reactions. Nodules are usually as a consequence of an exaggerated immune response which may be due to a biofilm or immunological reaction to the filler.
Management of arterial occlusion is a medical emergency, the event is accompanied by pain and pallor distal to the occlusion. This occurs most commonly in areas of the mid-face and have included occlusion of the retinal artery causing blindness (risk estimated at 1 in 3 million). If HA has been the filler used then hyaluronidase should be injected immediately in order to prevent the cascade events leading to necrosis. If pustules and erythema are already visible then symptomatic treatment is commenced.
Hyaluronidase is an essential tool for all clinicians administering fillers, and is used in an emergency for inadvertent injection of HA into a vessel, and on a non-urgent basis for removing small amounts of unwanted filler. It is a powder reconstituted with saline to give a solution of 150 IU/ml. The area of injection and the field of discolouration is injected with minimum 200 IU hyaluronidase and repeated at 60 minute intervals. If there has been acute visual loss due to vessel occlusion then a retrobulbar injection of hyaluronidase is required.
The plan for treatment of a nodule depends on the type of filler injected, a biopsy can be taken if there is uncertainty. If an HA filler has been used then hyaluronidase around the nodule should be injected - intralesional steroid injection can then be used in combination with oral antibiotic.
Botulinum toxins (BTXs) are neuromodulators that act by blocking acetylcholine release from axon endings at the neuromuscular junction and is used to treat a variety of conditions caused by muscle hyperactivity. Within the field of aesthetic medicine BTXs are used to reduce the activity of dynamic muscles that contribute to facial lines and to reduce the volume of sweating in hyperhidrosis.
The core molecule in BTX is a 150 kDa protein with three domains and different neurotoxin associated proteins (NAPs) according to the serotype. Its action is at the neuronal endplate and works by blocking release of acetylcholine and inhibiting muscle contraction. BTX-A binds to the SNAP 25 proteins and BTX-B binds to the vesicle associated membrane protein. As new synaptic proteins are synthesised over time, normal function of muscle returns usually around four to six months. The potency of BTX is measured in units of activity; units between different toxin types and different products vary and each product should be considered as a different drug.
Injection site selection follows a common theme; however, as each patient will present with their own particular set of muscular dynamics it is important that placement of the product is individualised. In order to determine this assessment should be made on muscle contraction and at rest, facial asymmetry should be noted and injection site placement and dosage adjusted accordingly. Adjustment should be made to the dosage depending on the bulk of the muscle being treated and attention paid to the desired depth of the injection.
The glabellar lines are the most commonly treated site and those first studied to gain approval for its cosmetic use. The muscles targeted are the depressors; corrugator and procerus, with a smaller contribution from the superolateral orbicularis oculi muscle. The frontalis muscle is an elevator and responsible for horizontal forehead lines, injection along this muscle must also be targeted to reduce these (Figure 26-5). A balance must be struck to ensure that there is not overtreatment leading to brow ptosis. It is important to select the correct injection sites depending on the preference for a flat or arched eyebrow.
Lateral canthal lines (crow's feet)
These lines are caused by contraction of the orbicularis oculi, BTX is injected into the lateral aspect 1-2 cm lateral to the ocular bony rim.
Common sites treated in the mid face include the lines on the lateral nose treated with a small dose of BTX into the nasalis muscle. Nasal tip ptosis can be improved with injection into the septi nasi muscle. Gummy smile can be corrected with injection into the elevator labii alaeque nasi muscle.
The lower face has a higher risk of undesired outcome due to the overlap and interplay of the muscles, particularly around the mouth. Injection to the depressor anguli oris can reduce the downturned appearance to the lateral aspects of the lip. With age the mentalis muscle continues to contract that can lead to puckering of the overlying skin and upward turned chin, adding further to depression of the angles of the mouth. This muscle is injected in its centre.
Injection into the masseter muscle can be exceptional in its benefit for improving bruxism and for slimming the angle of the jaw. The masseter muscle can be isolated by clenching the teeth and palpating the medial and lateral border, the inferior border is the mandible. The muscle is injected at three injection sites deep into the muscle. It is important to ensure that the injections are deep enough to prevent paralysis of only the superficial masseter, resulting in a chipmunk appearance, with bulging of the deep masseter.
The platysma muscle encircles the neck and with age, vertical bands become more prominent and produces depression of the lower lateral face. Small amounts can be injected along the superior border of the platysma under the angle of the jaw and along the platysma bands, thus allowing the muscle to relax (Figure 26-6) and prevent the downward pull of the lower facial muscles and overlying skin.
The use of BTX for hyperhidrosis is well documented and approximately 25 intradermal injections are made in a grid like pattern across the axilla. Effects last approximately six months.
The main serious side effects seen with BTX do not tend to occur in aesthetic dermatology because the doses used are low. The main causes for poor outcome are usually as a consequence of incorrect dose, injection site selection, and poor injection technique. Knowledge of the interplay of all of the facial muscles is essential to reduce the risk of poor outcome. The most frequent side effects include bruising, brow, lip, asymmetry, and ptosis and less frequent side effects include headache, diplopia, dry mouth, and dry eyes.
To reduce the risk of bruising, care should be taken to avoid injection through or into a vessel, if inadvertent injection at a vessel occurs, firm pressure should be applied to the injection site to reduce expansion of the bruise.
BTX injections are contraindicated in patients with myasthenia gravis or similar neuromuscular disorder; and should be avoided in patients who are pregnant or breastfeeding. A careful medication history and examination should be undertaken prior to treatment. BTX can be used in combination with dermal fillers and with resurfacing procedures to improve aesthetic outcome.
Chemical peels cause controlled skin destruction and are classified according to the depth of the wound they create. They are commonly used to treat scarring, dyschromia, photoageing, and active acne. Treatment benefits and side effects correlate with the depth of tissue involved.
Superficial peels affect the epidermis and dermal-epidermal interface and are useful in the treatment of: mild dyschromias, acne, post-inflammatory pigmentation, and actinic keratosis and can be used to achieve skin radiance and luminosity. They can be used in nearly all skin types and epidermal regeneration occurs within three to five days, there is very little downtime associated. Indications for medium depth peels include wrinkles, photodamage, solar lentigines (Figure 26-7), and atrophic scars. Deep peels are used rarely now due to advancements in laser technologies, but are useful for marked photoageing, atrophic scarring, and deep wrinkles.
Figure 26-8 shows the depths of penetration of the various agents used.
Alpha hydroxyl acids (AHA) are a group of chemicals that contain a carboxylic acid substituted with a hydroxyl group. They are found naturally occurring or can be synthesised. They act by reducing cell-cell adhesion resulting in desquamation, they also increase dermal collagen. The most commonly used AHAs are glycolic acid and lactic acid, because they are small molecules it allows for greater penetration through the skin. They are generally well tolerated although they can cause burning, pruritus, and hyperpigmentation.
Salicylic acid is a beta hydroxyl acid and is the preferred chemical peel for patients with comedomal acne, as it is lipophilic and concentrates in the pilosebaceous apparatus.
Jessner's Solution - is a blend of resorcinol, salicylic, lactic acid, and alcohol primarily it used as a superficial peel for skin preparation before a trichloroacetic acid (TCA) peel.
Trichloroacetic acid (TCA) is an analogue of acetic acid and acts on the skin by TCA of proteins and a coagulative necrosis this causes a frosting on the skin. The concentration of the TCA used will dictate the depth of the peel.
Phenol is used as an agent to create a deep peel by complete coagulation of epidermal keratin proteins, a side effect, however, is significant bleaching and resultant hypopigmentation.
Baker-Gordon utilises phenol in a formulation that permits deeper penetration into the dermis than full-strength phenol. It is mixed with Septisol (liquid soap), which reduces skin tension, allowing a more even penetration, and croton oil, which enhances phenol absorption. Patient selection is critical in that there is a significant risk of complications such as scarring and loss of pigment.
The depth of peel is decided by the molecule used and its concentration, other factors that will have an effect are the additional use of any mixing agents, number of coats applied, degreasing of the skin, pressure used in application, and differences in skin thickness. Patient factors such as concomitant retinoid use or known eczema will also have an effect.
Pre-peel consultation is important to ascertain the patients concerns and the acceptability of risk and length of downtime. A review of risk for hyperpigmentation and scarring should be undertaken and it should be noted that atrophic skin may be more sensitive to chemical peels. The skin can be primed four weeks before to allow for uniform penetration of the peeling agent. A topical retinoid is used to reduce the thickness of the stratum corneum and the consequent increase in epidermal turnover reduces epidermal melanin.
The standard tray would have acetone (for skin degreasing), gauze, cotton-tipped swabs, water spray, bland moisturiser, timer and neutraliser (for AHA), and a syringe of saline (for use if there is accidental spillage of the peeling solution into the eye).
The skin should be washed with soap and water and the skin disinfected with alcohol, the skin is then degreased using acetone and this allows for a more even depth of peel. Vaseline is applied over sensitive areas to protect them. Each agent has its own particular technique to allow for optimal results, but usually starts at the forehead, working in a clockwise motion around the face, with eyelid skin treated last.
AHA peel solution should be applied quickly starting at the forehead. The area is massaged with a gloved hand until the desired contact time has been reached. The concentration of free acid and the contact time will determine the extent of peel. Once the end point is reached then the glycolic acid (GA) is neutralised with sodium bicarbonate. The GA is completely neutralised once the bubbling ceases, after which the face should be washed and mild emollient applied.
TCA is rubbed into the skin with gauze until the end point is reached and the areas are washed with water. The end point for a superficial epidermal peel is erythema, and a medium depth peel is a white frost with visible background erythema (Figure 26-9).
Jessner's peel solution is applied to the skin and due to precipitation of the chemical a light whitening occurs (this is not frosting due to tissue coagulation). Up to three layers are applied, allowing each layer five minutes to dry - more layers increase the depth of the peel. There is no need to neutralise.
Salicylic acid 20-30% is applied to the face and a second application on top of acneiform inflammatory papules.
Following a superficial peel a bland emollient can be used 2-4 times a day for two days. Following a medium depth peel a bland emollient is dabbed onto the skin to keep it moist and keep the necrotic area of skin in place. A gentle cleanser can be used and the skin should not be picked at. The skin will take five to seven days to re-epithelialise.
Side effects and complications
Side effects and complications of chemical peels tend to occur more commonly when peels are deeper, agents applied for longer, and in darker skin types. When treating darker skin types agents such as Jessner's, salicylic acid, or glycolic acid should be used as they have a lower risk of post peel complications.
Persistent erythema can occur in some patients and this usually resolves by 60 days; the patient should be observed for scar formation. The risk of infection increases with the depth of peels due to loss of barrier and crust formation leading to bacterial colonisation. Infections should be treated quickly and aggressively with appropriate oral antibiotics and wounds dressed with acetic acid soaks, to prevent scar formation.
Chemical burn of the face (Figure 26-10) can occur even with superficial peeling agents if they are left on the skin for too long, burns tend to heal with post-inflammatory hyperpigmentation.
Milia and acneiform eruptions can occur two to three weeks post peel and are likely as a consequence of the occlusive effects of the thick ointments used post treatment.
Post-inflammatory hyperpigmentation can take months to resolve and treatment is with broad-spectrum sunscreen, topical hydroquinone, vitamin C, and tretinoin. Hypopigmentation is a complication of deep chemical peels as a consequence of mass melanocyte destruction and may be permanent.
Scarring is rarely seen in superficial peels and are usually as a consequence of infection or reduced wound healing, Hypertrophic scarring can be treated with topical steroids, pulsed dye lasers, and fractionated laser treatment.
Microneedling causes a physical injury to the skin by penetration of microneedles to a specific depth. This induces a wound healing cascade and neocollagenesis. It is effective and safe in the treatment of acne scars, wrinkles, and striae. The microneedles are arranged on a roller drum (192 needles), a pen, or a stamp and are available in different lengths depending on the depth of penetration required. The procedure causes a repair mechanism and neocollagenesis based on the same pathway as that by fractionated laser treatment, with the difference being that it involves a mechanical traumatic micro-injury and not a thermal-induced micro-injury. The procedure is cost-effective and an excellent alternative where lasers are not available or in patients with darker skin type and at risk of hyperpigmentation from thermal injury.
The facial skin will have a topical anaesthetic agent applied for a minimum of 45 minutes. The needles are inserted into the skin at exactly 90° and in a multidirectional pattern to ensure maximal coverage. Dragging of the needles should be avoided to ensure that there is not shearing of the skin. For therapeutic benefit and neocollagenesis, pinpoint bleeding will be achieved. The skin will have a 'sunburnt' appearance to it for the next 48 hours and strict sun avoidance must be adhered to. The skin is oedematous for a number of days and the long-lasting benefit of neocollagenesis is only seen at three months post treatment. Treatments are usually multiple and spaced six weeks apart.
The procedure can be used in combination with topical application of platelet-rich plasma (PRP) allowing transdermal delivery. PRP is a concentrate of platelet-rich plasma protein and is derived by collection of autologous whole blood that is double centrifuged. Despite evidence being poor for its role in skin remodelling it is a popular treatment for rejuvenation.
Radiofrequency can also be used to tighten tissue by heating the tissue at a selected specific depth, achieved by adjusting the frequency. Water is the target of the process; local heat injury induces an inflammatory response and neocollagenesis ensues. Radiofrequency is also used for body contouring, when the same technology is applied to the adipose tissue. Devices can be monopolar or bipolar as well as fractional. Erythema and oedema are the common side effects and this resolves within 24 hours, the safety profile especially of the newer devices is excellent, although patients must be set reasonable expectation of effectiveness.
Surgical means of body contouring involves downtime and rare but highly significant risks, therefore the market for non-invasive technologies has grown dramatically.
Cryolipolysis uses controlled cold exposure to selectively damage adipocytes which occurs gradually over three months. The side effects are minimal but include erythema, bruising, and temporary paraesthesia, and care is needed in those patients with cold-induced conditions.
High-intensity focused ultrasound ablates subcutaneous adipose tissue and induces cell necrosis. The areas around the focal zone do not increase in temp to the same degree and therefore are unaffected. Inflammatory response results in metabolism of the disrupted tissue and overall volume loss at the adipose layer. The device is painful and side effects include tenderness and bruising at the site.
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