Microneedling
Microneedling is a relatively new minimally invasive procedure involving superficial and controlled puncturing of the skin by rolling with miniature fine needles. Microneedling was initially introduced for skin rejuvenation, but now it’s used for a wide range of indications, including acne scars, acne, post-traumatic/burn scar, alopecia, skin rejuvenation, drug delivery, hyperhidrosis, stretch marks, and many more. It is very safe for dark skin types, where risk of postinflammatory pigmentation is very high with other techniques that damage the epidermis. Traditionally, it’s used as a collagen induction therapy for facial scars and skin rejuvenation, but it is now widely used as a transdermal delivery system for therapeutic drugs and vaccines.
The standard medical dermaroller has a 12 cm long handle with a 2 x 2 cm wide drum-shaped cylinder at one end studded with 8 rows and 24 circular arrays of 192 fine microneedles, usually 0.5–3mm in length and 0.1–0.25 mm in diameter. The microneedles are synthesized by reactive ion etching techniques on silicon or medical-grade stainless steel and pre-sterilized by gamma irradiation. Rolling with the standard dermaroller over an area of skin for 15 times results in about 250 holes per square cm up to the papillary dermis depending on the pressure applied. Each pass produces 16 micro punctures in the stratum corneum per square cm without damaging the epidermis significantly.
Micro punctures are created using microneedles to produce a controlled skin injury without actually damaging the epidermis. The micro injuries lead to minimal superficial bleeding and set up a wound healing cascade with release of various growth factors such as platelet derived growth factor (PGF), transforming growth factor alpha and beta (TGF-𝛂 and TGF-𝜷 ), connective tissue activating protein, connective tissue growth factor, and fibroblast growth factor (FGF). The needles also break down the old hardened scar strands and allow it to revascularize. Neovascularization and neocollagenesis is initiated by the migration and proliferation of fibroblasts and laying down of intercellular matrix. Another proposed hypothesis explains that resting electrical membrane potential of cells is approximately -70 mV, and when needles come near the membrane, it increases quickly to -100mV, triggering increased cell activity and the release of various proteins, potassium, and growth factors from the cells into the exterior leading to the migration of fibroblasts to the site of injury, which causes collagen induction. The needles do not create a wound in a real sense, just fooling the cells in believing that the injury has occured.
Consumers can buy at-home microneedling rollers over the counter. But for best results, microneedling should be administered by a dermatologist using more advanced equipment. The dermatologist can adjust the device depth according to the area of the skin and deposit medication, such as topical tretinoin or vitamin C, deeper into the skin. At-home microneedling devices only superficially affect the skin, penetrating just the outer layer, the stratum corneum or epidermis and reaching 0.25 mm deep. Professional devices can go deeper (2 mm to 3 mm deep), reaching the dermis. Professional devices are also electrically powered and evenly pushes the microneedles into the skin. Home versions rely on manually rolling the barrel over the skin to create small punctures.
References:
Singh, A., & Yadav, S. (2016). Microneedling: Advances and Widening Horizons. Indian dermatology online journal. Retrieved March 21, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4976400/
Yale Medicine. (2021, June 23). Microneedling. Yale Medicine. Retrieved March 21, 2022, from https://www.yalemedicine.org/conditions/microneedling
Microneedling
Microneedling is a procedure to treat scars involving repetitive puncturing of the skin to disrupt the collagen connecting the scar tissue. When tissue is damaged, the body forms scar tissue including atrophic, hypertrophic, and keloid scars. Atrophic scars are commonly formed after inflammatory acne leaving indentations in the skin. This is due to a destruction of collagen and is permanent. The duration and severity of the acne, as well as a delay in therapy affects the formation of atrophic scars. A needle of 1 mm is most commonly used. Needles tend to be longer for treating scars and for thicker skin like around the nose. Shorter needles are used for aging skin and should also be used on thin skin like around the eyes. The needle punctures the stratum corneum, creating controlled injury with minimal damage to the epidermis. The small holes formed will promote collagen and elastin production in the lining of the dermal blood vessels. Studies have shown there is also upregulation of vascular epithelial growth factor (VEGF), fibroblast growth factor (FGF)-7, epidermal growth factor (EGF), and transforming growth factor (TGF)-β (Juhasz & Cohen). Neovascularization and neocollagenesis help to remodel the skin. After a few weeks, type III collagen that is newly formed turns into type I collagen, decreasing the appearance of scars.
Microneedling is indicated for pigment disorders, alopecia, acne scars, burn scars, hypertrophic scars, and primary axillary hyperhidrosis. Microneedling is contraindicated in patients with active acne or herpes infection, moderate or severe eczema or psoriasis, keloidal tendencies, immunocompromised patients, and it should not be used in areas that patients have received botox (Litchman, G. et al.). There are many advantages of this procedure over other skin procedures. The most important is that microneedling does not cause hyperpigmentation like laser procedures or chemical peels. This procedure causes less damage to the skin by maintaining the integrity of the epidermal layer.
A cross-sectional study conducted on 50 patients demonstrated the efficacy of microneedling for post acne scars. The patients underwent 4 procedures of microneedling every 3 weeks. 73% of patients showed downgrading from grade 4 to grade 2. In 20 patients that had grade 3 scars, 20% went to grade 1. Furthermore, all patients that had grade 2 scars downgraded to grade 1 (Farrukh, et al.). These results display how microneedling is significant in the treatment of post-acne scarring.
A study was conducted to determine whether microneedling combined with platelet-rich plasma worked better for acne scars rather than microneedling on its own. Platelet-rich plasma contains growth factors and bioactive cytokines (Kang & Lu). The study proved that there was increased efficacy when these procedures were used in combination. The results showed improved satisfaction of patients and better Goodmans Quality Scores (GQS) from dermatologists. There was also no difference in side effects like erythema or edema. There is a possible synergistic mechanism between these two procedures. The microwounds that are created during microneedling may provide enhanced absorption of the growth factors and cytokines by the skin (Kang & Lu). There is increased collagen and elastin deposition demonstrating a synergistic effect.
Acne and acne scarring can create psychological issues for many people. Microneedling is a way to change people's lives and improve confidence by eliminating scars. Studies have proven its efficacy in renewing the damaged skin.
Resources
Farrukh, A. K., Ahmad, S., Mehrose, M. Y., Saleem, M., Yousaf, M. A., Mujahid, A. M., Rehman, S. U., & Tarar, M. N. (2019). Efficacy Of Micro-Needling On Post Acne Scars. Journal of Ayub Medical College, Abbottabad : JAMC, 31(3), 336–339.
Iosifidis, C., & Goutos, I. (2019). Percutaneous collagen induction (microneedling) for the management of non-atrophic scars: literature review. Scars, burns & healing, 5, 2059513119880301. https://doi.org/10.1177/2059513119880301
Juhasz, M. L. W., & Cohen, J. L. (2020). Microneedling for the Treatment of Scars: An Update for Clinicians. Clinical, cosmetic and investigational dermatology, 13, 997–1003. https://doi.org/10.2147/CCID.S267192
Kang, C., & Lu, D. (2022). Combined Effect of Microneedling and Platelet-Rich Plasma for the Treatment of Acne Scars: A Meta-Analysis. Frontiers in medicine, 8, 788754. https://doi.org/10.3389/fmed.2021.788754
Litchman, G., Nair, P. A., Badri, T., & Kelly, S. E. (2022). Microneedling. In StatPearls. StatPearls Publishing.
Sitohang, I. B. S., Sirait, S. A. P., & Suryanegara, J. (2021). Microneedling in the treatment of atrophic scars: A systematic review of randomised controlled trials. International wound journal, 18(5), 577–585. https://doi.org/10.1111/iwj.13559