What is Microneedling Skin Treatment?
Microneedling, also known as percutaneous collagen induction (PCI), minimally invasive treatment of numerous dermatologic conditions. These techniques used needles to disrupt dermal collagen to trigger an inflammatory cascade, resulting in dermal remodeling and skin resurfacing. The applications for microneedling have expanded over the past few decades. It includes the treatment of acne vulgaris, scars, facial rejuvenation, dyspigmentation, alopecia, hyperhidrosis, and TDD.
Microneedling: Equipment
Understanding the equipment is essential given the wide variety of microneedling devices and therapy goals, as it can also serve as a medication or energy delivery method. The original and most straightforward microneedling device is the drum-shaped roller. There is significant variability in the types of rollers, with needles ranging from 0.5 to 3 mm in length and 0.1 to 0.25 mm in diameter.
Rollers tend to offer the best treatment effect over larger flat areas such as the cheek and forehead. They can become entangled with hair around the scalp, and their use is difficult for narrow areas, as in perioral resurfacing.
The next most common device is an electronic pen device, which uses disposable needle cartridges with a titratable needle length and penetration speed. These devices tend to offer improved control over narrower channels in the lip, nasal, and periocular treatment areas.
In addition to the mechanical roller and pen devices, there are now combination devices that include microneedling with concomitant fractional radiofrequency delivered at the needle tip, vacuum-assisted infusion of medications, or light-emitting diode (LED) therapy.
Following treatment, skin changes will occur in a non-inflammatory wound-healing cascade. After the initial punctuate bleeding resolves in the hours after treatment, mild swelling, superficial bruising, and erythema will remain. These will begin to improve along with any skin flaking within three days.
These skin changes are part of the healing process after an injury from microneedling that leads to platelet and neutrophil release of platelet-derived growth factor, fibroblast growth factor, and TGF-3. This will subsequently lead to the intercellular matrix production of collagen, elastin, and epidermal thickening.
These clinical and histologic findings will resolve in the first week after treatment and are followed by fibroblast deposition of collagen type III, increased gene, and protein expression of collagen and glycosaminoglycans, and skin regeneration.
Different collagen organization, neovascularization, and scar tissue remodeling will lead to the clinical improvement seen in 2 to 3 weeks after treatment with the thickened epidermis, improved texture, and elevation of depressed scar or rhytids.
Results can vary, and multiple treatments may be necessary depending on the treatment indication. It is thus important to continue taking patient photos after each treatment so that both the provider and the patient can track the progress.
Subsequently, these changes lead to the production of collagen, elastin, and epidermal thickening. By inducing these controlled skin injuries, there is neocollagenesis from fibroblast proliferation. Then, a fibronectin network provides a scaffold for initial type III collagen deposition and subsequent replacement with type I collagen in a standard wound remodeling cascade.
In addition, a synergistic effect is observed in concomitant therapies. One such example occurs in intradermal platelet-rich plasma injections performed with microneedling; the effect is believed to be through the increased concentrations of platelet-derived growth factor.
Fewer devices have combined the benefits of microneedling with radiofrequency to deliver energy deep into the skin. These combination devices cite the benefits of therapy of both established modalities working together to promote neo-collagenesis and improved skin resurfacing.
Microneedling therapy carries a decreased risk of many of the cutaneous adverse effects with conventional resurfacing modalities. Compared with ablative procedures, microneedling keeps the epidermis partially intact, and the retained skin barrier hastens recovery and limits the risks of infection and scarring.
Non-ablative and fractional lasers also preserve much of the top layer of the skin epidermis. Patients with darker skin phototypes can be at risk for pigmentary changes.
The use of microneedling has further expanded with the advent of fractional radiofrequency microneedling (FRFM). In FRFM, insulated needles penetrate the skin and release radiofrequency currents from the needle tips producing therapeutic changes in dermal structural components and accessory glands without destroying the epidermis. This technique is also used to augment transdermal drug delivery through pores created through the stratum corneum.
Microneedling is also used to enhance TDD through several methods, including pore creation through the skin, topical drug application, drug-coated microneedle arrays, and direct drug injection through hollow microneedles.
Microneedling can also be synergistically combined with other procedures, such as iontophoresis, electroporation, and sonophoresis. Microneedling before the topical anesthetic resulted in a significantly reduced pain score than lidocaine-prilocaine alone.
Mechanical penetration with the microneedling device has also been shown to facilitate enhanced delivery of medications or radiofrequency. Topical medications, such as minoxidil, trichloroacetic acid, and 5-fluorouracil, were improved delivery with microneedling.
Patient Selection and Contraindications of Microneedling
Microneedling has a wide variety of applications for skin resurfacing and treatment.
Resurfacing indications:
- Initial stages of facial aging or photodamage
- Fine rhytides and furrows
- Restore skin tightness and thickness
- Seeking to avoid dermabrasion or laser treatment
- Seeking rapid recovery with topical anesthesia only
- Seeking to avoid less sun-sensitive skin post-treatment
Other cutaneous indications:
- Scars (atrophic, acne, hypertrophic, burn)
- Alopecia (androgenetic, areata)
- Pigmentary disorders (melasma, vitiligo, periorbital melanosis)
- Primary axillary hyperhidrosis
- Striae rubrae (stretch marks)
- Verruca
- Actinic keratoses
Initial patient selection for Microneedling
Patients with early signs of facial aging seek to restore skin tightness, diminish fine wrinkles, and avoid more invasive dermabrasion or laser treatment.
This technique is reasonable for those patients seeking healthier skin, using a less expensive technique and with a shorter healing phase than lasers. Microneedling also avoids sun-sensitive skin following treatment by maintaining the intact epidermis instead of more ablative techniques of resurfacing.
Patients desiring to resurface with topical anesthesia only and rapid recovery can also benefit from being selected for microneedling over more intensive peels or laser therapy.
Numerous other indications for microneedling beyond traditional skin resurfacing have also been studied, such as using microneedling as a drug or energy delivery method. These indications include scars (atrophic, acne, hypertrophic, burn), alopecia (androgenetic, areata), striae rubrae (stretch marks), pigmentary disorders (melasma, vitiligo, periorbital melanosis), verruca, primary axillary hyperhidrosis, and actinic keratosis.
Contraindications for microneedling are few and minimally reported. Most notable are those at risk of inflammatory or hypertrophic scarring, such as patients with a keloid predisposition, inflammatory acne, or local infection. I should also avoid patients with active herpes labialis or immunosuppression (chemotherapy or radiation).
Practitioners should avoid areas with chronic skin diseases such as eczema, rosacea, or potential skin malignancy to avoid disseminating abnormal cells by microneedle implantation.
Counsel and precaution are necessary when patients have clotting disorders or in patients who are on therapeutic anticoagulation, as there can be bleeding.
Another avoidable complication is performing microneedling in the local area of botulinum toxin injection, as it may lead to diffusion to undesired areas.
Microneedling Preparation
After screening for appropriate contraindications already listed, patients should undergo strategic preoperative planning and preparation and informed consent that includes the benefits, risks, and potential complications of microneedling.
Preoperative pictures are essential for all patients for documentation and detailed assessment of outcomes following treatments.
Practitioners should also consider waiting for any recent suntan to have faded before treatment to avoid post-treatment dyspigmentation.
Also, as with other skin resurfacing techniques, patients with a history of herpes labialis should be treated with a 1-week prophylactic oral antiviral beginning the day of treatment.
Skin preparation on the day of treatment is essential. Patients should meticulously clean the planned treatment area and ensure that all makeup, lotions, and other topicals are removed before arrival.
Depending on the size of the treatment area, topical anesthesia is covered with an occlusive dressing for 15 to 45 minutes before treatment.
Regardless of the local topical anesthetic used, once an anesthetic effect is reached, I should remove it with saline-soaked gauze and cleanse the skin with alcohol before microneedling. Local anesthetic injection or a nerve block can benefit certain patients in sensitive areas such as the upper lips, but this is typically unnecessary.
Microneedling Technique
Specific technical considerations when performing microneedling must be adhered to provide optimal results. I should determine the needle length and penetration depth based on the treatment area. A thin skin or bony surface, as in the periocular, lip, and nasal areas, requires shorter needle lengths ranging from 0.25 to 0.5 mm.
Scars or areas with a thicker surface, such as cheek, chin, or non-facial areas, can easily tolerate needle lengths up to 2 mm. The needle speed can help minimize pain during treatment significantly as needle length increases.
After skin preparation with anesthetic and cleansing, as described previously, the device is often used with a lubricating agent. The topical hyaluronic acid-based gel is often selected for its active ingredient and lubricating benefit during treatment.
The needle length and speed are selected for the area, and the non-dominant hand is used to stretch the face while the dominant handholds devise and perform the microneedling. The instrument is moved in a direction perpendicular to the direction of the stretching force of the other hand.
The microneedling device should be passed in multiple directions to avoid creating track marks or microchannels of more significant injury in the same plane. The clinical endpoint of treatment is an evenly spread erythema, mild swelling, and transient punctate/pinpoint bleeding.
The number of passes with the device may be anywhere from 3 to 15 times based on the location, pathology, specific device, and, more importantly when the clinical endpoints are reached. Once the endpoints are reached in one area, I can place saline-soaked gauze until other areas are treated. Direct pressure is usually sufficient for any areas of persistent bleeding.
When the microneedling is completed, the skin is cleansed with sterile saline to remove any lubricating agent or debris. The treatment takes no longer than 15 to 20 minutes in total, depending on the size of the area treated, and can be repeated at monthly intervals until the desired outcome is reached. At this time, if additional topical medication is planned for delivery, it can be smoothly applied over the areas of microneedling treatment.
Post-microneedling Considerations
Immediately following the microneedling procedure, the patient will often have mild swelling, superficial bruising, and punctate bleeding. After any persistent bleeding has been controlled with direct pressure and any topicals have been applied, I can use ice-water-soaked dressings in the immediate setting.
There is often serosanguinous drainage, which may require collection with dressing changes in the first few hours. At this point, a layer of hyaluronic acid gel can be applied and allowed to dry. After 4 hours, a moisturizing cream or 1% hydrocortisone cream can be applied to the treatment area up to 4 times a day for the first three days, and the patient should avoid any makeup or cosmetic products during this time.
Although sun exposure is less risky with epidermal preservation, protection of the area from sun exposure and an additional sunblock of SPF 30 or higher over the hydrating cream are recommended in the first two weeks after treatment.
Regarding pain control, the patient should expect a mild, sunburn-like level of discomfort that should be controlled with acetaminophen as needed. Depending on the pathology being treated, repeat microneedling can be performed at monthly intervals and may require multiple treatments to reach the desired effect.
Many will pursue annual or semiannual treatments to maintain skin quality from photodamage and aging changes in resurfacing patients.
Problems and Complications of Microneedling
Infections and hypersensitivity reactions are rare. Given the noninvasive nature, topical anesthesia, and preservation of the epidermis, few significant complications develop following microneedling treatment. I can avoid most complications if practitioners adhere to the criteria in the patient selection and preoperative preparation sections, specifically avoiding patients with active herpes simplex and providing prevention in those with a previous history to avoid reactivation.
They are typically reported secondary to patient use topical cosmetic products, makeup, or nonprescribed skin treatments in the first few days after the procedure. Applying these productions can lead to skin bumps as a skin allergic reaction.
Some advocate topical antibiotic ointment (e.g., mupirocin) during the first few days to minimize the chances of bacterial infection, but this is not routinely recommended in the general population.
Dyspigmentation in patients with Fitzpatrick skin type IV to VI or those with immediate sun exposure is always a concern in skin resurfacing. Still, it has not been as severe in microneedling. Protection from UV light is still recommended, but microneedling appears to tolerate sun exposure better than more invasive resurfacing techniques that disrupt or ablate the epidermis.
Bleeding and bruising are typically self-limited and rarely a problem in patients undergoing microneedling. Of note, longer needle lengths, extending up to 3 mm, may lead to more swelling and bruising with an extending recovery into the first week after treatment.
Selection of appropriate needle length for the specific treatment area and avoiding multiple passes in sensitive areas is essential. More importantly, the operator should avoid microneedling across the same area beyond the clinical endpoints, especially in thinner skin or over a bony prominence. There have been reported cases of tram track–like scarring following microneedling treatment of acne scars. Practitioners should be concerned about these complications when treating patients with significant hypertrophic scarring or predisposition to keloid formation.
Fractional Radiofrequency Microneedling
Microneedles Fractional Radiofrequency (MFR) uses an array of microneedles arranged in pairs between which bipolar RF energy is delivered. The fractionally distributed energy creates zones of affected skin adjacent to unaffected areas.
The affected skin area is the result of thermal energy. Thermal energy results in deep dermal collagen injury that stimulates wound healing and dermal remodeling. The unaffected areas maintain skin integrity but, in the long term, serve as a reservoir of stem cells that promote and accelerate wound healing.
MFR showed skin wrinkles, laxity, texture, pigmentation, acne scars, and large facial pores. New collagen, elastin, and hyaluronic acid also occur. The most common side effects are erythema and edema, which are transient, and patient discomfort does not seem to be a significant disadvantage. I may use a topical anesthetic cream before the treatment to minimize pain.
Fractional microneedle radiofrequency (FMR) treatment is a new safe, and effective alternative for moderate to severe primary axillary hyperhidrosis. Proudly at MSI, a newer bipolar RF device effectively reduces the amount of sweating.
The combination of RF and fractional microneedle technology termed fractional microneedle radiofrequency (FMR) creates an effective method and better safety profile to destroy eccrine sweat glands by thermolysis at the interface of the deep dermis and subcutis. Prof Moawad suggests repeating treatment sessions to achieve a complete response.
Microneedling as Transdermal Drug Delivery System (TDDS)?
The technique of microneedling has been well-exploited to increase the penetration of drugs across the skin barrier. This has been proven in in-vitro skin models where enhanced absorption of larger molecules such as calcein has been observed.
M microneedles cover a range of activities between a transdermal patch and a hypodermic needle, attempting to gain the advantages of both and eliminate the disadvantages of each one of them. Micro-needling has been used for the transdermal delivery of several drugs, including minoxidil, tretinoin, and L-ascorbic acid.
Micro-needling has also been combined with other advanced techniques such as micropumps, sonophoresis, iontophoresis, and electroporation for better drug penetration. Micro-needling is often combined with topical tretinoin and vitamin C to treat acne scarring and skin rejuvenation.
Micro-needling enhances the effect of 5-aminolevulinic acid for more efficacious photodynamic therapy. They have been used in combination to treat actinic keratosis and photoaging. Penetration enhancement of minoxidil and platelet-rich plasma for androgenic alopecia is another application.
Concluding Thoughts
Various modalities exist for facial rejuvenation and skin resurfacing (e.g., dermabrasion and micro-dermabrasion. Although dermabrasion can achieve perfect skin resurfacing outcomes, it requires a certain level of expertise and experience to master the technique. As a result, its utility in skin resurfacing has been diminished after the widespread adoption of lasers, which can deliver a similar outcome with much less technical involvement by the operator.
Microdermabrasion and microneedling have gained popularity over the past two decades. They are easy to perform, cheaper, and less invasive, and provide fast recovery with exceptionally low complication profiles, making them extremely attractive for mild to moderate improvement patients. It is not surprising that many plastic surgeons and dermatologists dealing with facial rejuvenation have added these less invasive procedures to their current practice.
Overall, all three techniques are safe and effective for facial skin resurfacing when performed correctly on appropriately selected patients.
Comprehensive patient education on the procedure and postprocedural care and setting realistic expectations are essential for achieving an optimal result and ensuring patient satisfaction.
Given the increasing use of these techniques in facial rejuvenation, it is vital to continue scrutinizing their efficacy and safety.
Clinical Warnings
• Dermabrasion removes the epidermis and penetrates to the papillary or reticular dermis level, whereas microdermabrasion removes only the uppermost layer of the epidermis. Microneedling does not remove any skin layers and works by penetrating the skin with needles.
• Dermabrasion requires a certain level of expertise and experience to master the technique, whereas microdermabrasion and microneedling are less invasive and more straightforward to perform.
• Isotretinoin has been implicated in delayed wound healing and hypertrophic scarring; therefore, it should be discontinued for at least a year before these procedures.
• Patients with a history of herpes simplex infection should be treated with a 1-week prophylactic oral antiviral beginning the day of treatment to prevent reactivation of the disease and untoward aesthetic outcomes.
• Although microdermabrasion and microneedling are less invasive and allow faster recovery than dermabrasion, they usually require multiple treatments to achieve a less aggressive result. Therefore, I should set realistic goals and expectations before initiating treatment to ensure patient satisfaction.
• All three techniques are safe and effective for facial skin resurfacing and can be used either alone or in conjunction with other procedures for facial rejuvenation.
Conclusion
Over the past 20 years, the applications of microneedling in dermatology have grown drastically. The concept of subcision for scars has progressed to automated microneedling pens, MFR, and the facilitation of TDD. This review highlights the encouraging results and limitations that have been reported with microneedling for a variety of conditions, including scars, acne, melasma, photodamage, skin rejuvenation, and hyperhidrosis microneedling provides the advantage of epidermal preservation while promoting the production of dermal collagen and elastin.
Overall, its efficacy, safety, and ease of use make microneedling a favorable therapeutic alternative to consider. Given that microneedling, like lasers and other non-invasive devices, is being used increasingly by physicians and physician extenders, nurses, aestheticians, and even patients using at-home devices, continued research on the safety and efficacy of microneedling is essential.