Hair is an extension of personal expression, so it’s no surprise that treating hair loss is a high priority for those affected by alopecia areata. PRP injections have emerged as a popular treatment option for all kinds of hair loss with no adverse side effects, but how does this therapy stack up to traditional topical treatments? In 2016 researchers at the South Valley University in Qena, Egypt published the findings of a clinically controlled trial which compared the effects of PRP injections and minoxidil 5% to treat alopecia areata. The study found PRP injections to be more effective in treating the autoimmune driven hair loss disorder compared to minoxidil.
The study included 90 patients aged 10 to 40 experiencing alopecia areata for an average 28 months. Participants were randomized into three groups of 30 patients each. Group A was treated with minoxidil 5% twice daily for three months, group B received monthly PRP injections for three months (the exact injection methodology was not discussed), while group C received topical Panthenol cream twice daily as a placebo.¹
PRP Preparation Technique
Researchers utilized a single spin, test tube preparation technique. PRP was prepared from a 10 ml blood draw. The blood draw was isolated into two 5 ml test tubes then centrifuged at 3000 RPM for 10 minutes. Centrifugation stratifies the blood elements and isolates platelets from red blood cells. The process yielded about 4 ml of PRP. Assuming optimal preparation techniques, we can infer that the resulting serum contained a platelet concentration of 2.5x, though the researchers did not analyze the final product.
PRP Injections Significantly Increase Hair Growth
Hair growth results were assessed with trichoscopy, a dermoscopic scan used to evaluate the percentage of hair growth, short vellus hair and yellow dots. Alopecia areata is diagnosed by the presence of yellow, round, polycyclic dots at the sight of hair loss in addition to clearly defined circular patch(s) of sudden hair loss. Yellow dots are a sign of keratinous plugs in patients with alopecia areata. Pathogenic theories include lymphocytic attack of the hair follicle, genetic predisposition as well as environmental factors such as Epstein-Barr virus.²
Trichoscopy results revealed a significant increase in hair growth for patients in both the PRP and minoxidil groups. As to be expected, the control group did not show statistically significant hair growth. In the PRP group, researchers observed a statistically significant increase in fully pigmented hairs. While patients in the minoxidil group showed a significant increase in the average number of short vellus hairs. The presence of vellus hairs suggests disease remission,³ but vellus hairs are not fully mature and do not satisfy patient concerns. Increases in vellus hair is a sign of progress, but mature shaft development is the ultimate aim of hair growth therapies. Researchers concluded PRP was more effective than minoxidil because patients in the PRP group had earlier and better responses, as well as a significant decrease in short vellus hair, yellow dots and dystrophic hair.
Adverse Effects of PRP Therapy vs Minoxidil 5%
It is important to note that the autologous nature PRP treatments eliminates the risk of adverse side effects for patients receiving the therapy. Contrarily, minoxidil can cause skin irritation and allergic reactions. Adverse reactions to minoxidil also include increased hair loss because of the synchronization of the hair cycle. Most regrettably, results achieved with minoxidil are known to be temporary, hair growth disappears within months of treatment discontinuation.
Clinical Reproducibility and Study Shortcomings
The authors of this study neglected to include information key to clinical reproducibility. The authors did not mention the use of an anticoagulant which is necessary for the stratification of blood elements and can affect platelet concentration.⁴ The researchers concede that their PRP preparation method did not produce a serum with an optimal concentration of platelets. The positive results achieved by patients in the PRP group may be attributed to the use of an activator (an unknown amount of calcium gluconate). The study would have benefited from a detailed assessment of the prepared PRP serum to reveal platelet concentration and growth factor content of the serum. Additionally, the authors failed to include a detailed description of the injection methodology so that results could be reproduced.
How Does PRP Increase Hair Growth?
Positive results in the PRP group can be attributed to increased angiogenesis which supports hair growth in the anagen phase. Angiogenesis provides necessary blood flow to support hair follicle development. The healing power of PRP depends on preparation techniques that delivery viable platelets in adequate numbers. Platelet viability and activation is vital for effective PRP injections. Once activated, platelets release a wide variety of growth factors, tiny bioactive proteins that bolster tissue repair by increasing cell mitosis and chemotaxis. Specifically, angiogenesis is increased by fibroblast growth factor 7, transforming growth factor (alpha-beta), vascular endothelial growth factor, epidermal growth factor, and connective tissue growth factor.⁵ Additionally, the authors note the anti-inflammatory effects of PRP benefit patients with alopecia areata which is characterized by an increase in inflammatory cytokines.
- El Taieb, M. A., Ibrahim, H., Nada, E. A., & Seif Al-Din, M. (2016). Platelets rich plasma versus minoxidil 5% in treatment of alopecia areata: A trichoscopic evaluation. Dermatologic Therapy, 30(1), e12437. doi:10.1111/dth.12437.[researchgate]
- Rodriguez, T. A., & Duvic, M. (2008). Onset of alopecia areata after Epstein-Barr virus infectious mononucleosis. Journal of the American Academy of Dermatology,59, 137–139.[ncbi]
- Mahmoudi H, Salehi M, Moghadas S, Ghandi N, Teimourpour A, Daneshpazhooh M. Dermoscopic Findings in 126 Patients with Alopecia Areata: A Cross-Sectional Study. Int J Trichology. 2018;10(3):118-123.[ncbi]
- DCorrêa do Amaral R, Pereira da Silva N, Haddad N, Lopes L, Ferreira F, Filho R, Cappelletti P, Mello W, Cordeiro-Spinetti E, and Balduino A. Platelet-rich plasma obtained with different anticoagulants and their effect on platelet numbers and mesenchymal stromal cells behavior in vitro. Stem Cells International. 2016; Article ID 7414036, 11 pages.[ncbi]
- Dhurat R, Sukesh M. Principles and Methods of Preparation of Platelet-Rich Plasma: A Review and Author’s Perspective. Journal of Cutaneous and Aesthetic Surgery. 2014;7(4):189-197. doi:10.4103/0974-2077.150734.[ncbi]