Toxins and fillers

Botulinum toxins are neuromodulators produced by the Gram-positive anaerobic bacteria Clostridium botulinum. They act by binding to the receptor sites on presynaptic autonomic nerve terminals. The toxin inhibits acetylcholine release and causes muscle paralysis. The role of toxins in neck rejuvenation is selective and limited. Patients presenting with prominent platysmal banding and rhytides with mild-to-moderate skin excess may benefit from botulinum toxin type A injections. This treatment is also suitable for patients who do not wish to undergo surgical procedures. The total amount of toxin injected depends on the extent of the bands. The number of injections per band varies from two to 12, and the maximum dose may not exceed 10 units per band, with the maximum total dose less than 100 units8. Successful management of neck rhytides with botulinum toxin has been reported in a number of studies8, 9. Care should be taken to avoid large doses and inadvertent injections into the strap muscles of the neck. Complications include dysphagia, oedema, ecchymosis, muscle soreness, and discomfort.

Table 1

Fillers are mainly used to augment soft tissue deficiency and have a limited role in rejuvenating the neck and décolletage. There are many commercially available soft tissue fillers on the market, among which hyaluronic acid fillers are considered the gold standard. Commercially available fillers include bovine collagen, human collagen, porcine collagen and hyaluronic acid of animal and biosynthetic origin, poly-L-lactic acid (PLLA), calcium hydroxylapatite (CaHA), and polymethylmethacrylate (PMMA). Dermal fillers are mainly used to provide deep dermal hydration, moisturisation and volumisation, leading to improved quality and tone of the skin. The fine lines of the décolletage caused by ageing and photodamage can be treated using dermal fillers. The complications are minimal and the treatment is temporary and needs maintenance. Toxins and fillers are often combined to provide neck and lower facial rejuvenation7–10.

Cosmeceuticals

These are topical agents, which comprise a combination of cosmetic and pharmacological substances. The efficicacy of cosmeceuticals on ageing skin depends on a number of factors. The main component in the product must have an active ingredient that has a significant effect on ageing skin. It is equally important that the active ingredients should be able to penetrate the stratum corneum and be delivered to the targeted areas of the skin. The active ingredients in such products include retinoids, depigmenting agents, antioxidants, peptides, growth factors and hydroxy acids. Most of these products have no scientifically proven value in reversing or halting the ageing process, while there is some evidence for products having a scientifically-proven effect on ageing skin.

Retinoids are derived from vitamin A, which has a clinically proven effect on ageing and sun-damaged skin. Topical cosmeceutical retinoids include retinyl esters, retinol, retinaldehyde and oxoretinoids. Retinoids have an impact on skin texture, pigmentation, and fine wrinkles. They act by enhancing cell turnover, stimulating glycosaminoglycan synthesis and collagen synthesis. They are also claimed to impede the breakdown of collagen. A number of studies have shown the beneficial effects of these products on the skin11–13.

Table 2

Similarly, hydroxy acids are also common components in cosmeceuticals. They are organic carboxylic acids and can be broadly classified into alpha (AHA) and beta hydroxy acids (BHA). The AHAs include glycolic and lactic acid, and BHAs include salicylic acid. These components enhance epidermal shedding and sloughing. The other important group of ingredients in cosmeceuticals are antioxidants. Some of the most effective antioxidants are vitamin C-related compounds. They are powerful antioxidants and are important in regulating collagen synthesis and thought to reverse changes related to photoageing. Hydroquinone is an aromatic organic compound that has been used to treat hyperpigmentation. Recent studies by Leyden and Parr revealed significant improvements in photodamaged skin of the décolletage with the combined treatment of hydroquinone, tretinoin and zinc maleate14. The efficacy of the ingredients in cosmeceuticals and their potential side-effects have not been studied completely. More clinical control studies are required before prescribing higher concentrations of these components in topical preparations (Figure 1).