A comprehensive review of data on efficacy, safety and mechanism of action of platelet-rich plasma (PRP) injections in treating alopecia areata.

1. Platelet-Rich Plasma in the
Treatment of Alopecia Areata
Hind Almohanna, MD
Clinical Fellow
Department of Dermatology & Cutaneous Surgery
University of Miami, Miller School of Medicine, Miami, FL

2. Objectives
• Mechanism of action of Platelet-Rich Plasma (PRP)
• Preparation of PRP
• Efficacy
• Safety
• Contraindications

3. Platelet-rich plasma (PRP)
• Possible hemostatic agent utilized in the surgical situation1,2
• Used in wound healing and tissue repair3:
• Plastic surgery
• Orthopedics
• Maxillofacial surgery
• PRP in dermatology:
• Scar revision, skin rejuvenation, wound healing, and striae distensae 4.
• AGA, AA, and to boost graft survival in hair transplantation5.
1. DelRossi AJ, Cernaianu AC, Vertrees RA, Wacker CJ, Fuller SJ, Cilley JH, Jr., et al. Platelet-rich plasma reduces postoperative blood loss after cardiopulmonary bypass. J Thorac Cardiovasc
Surg. 1990;100(2):281-6.
2. Cieslik-Bielecka A, Choukroun J, Odin G, Dohan Ehrenfest DM. L-PRP/L-PRF in esthetic plastic surgery, regenerative medicine of the skin and chronic wounds. Curr Pharm Biotechnol.
2012;13(7):1266-77.
3. Albanese A, Licata ME, Polizzi B, Campisi G. Platelet-rich plasma (PRP) in dental and oral surgery: from the wound healing to bone regeneration. Immun Ageing. 2013;10(1):23.
4. Arshdeep, Kumaran MS. Platelet-rich plasma in dermatology: boon or a bane? Indian J Dermatol Venereol Leprol. 2014;80(1):5-14.
5. Schiavone G, Raskovic D, Greco J, Abeni D. Platelet-rich plasma for androgenetic alopecia: a pilot study. Dermatol Surg. 2014;40(9):1010-9.

4. PRP mechanism of action
• PRP increases concentrations of growth factors, cytokines, and
proteins modulating inflammatory pathways and tissue repair
• Platelets become activated and release the contents of alpha granules
that contain:
• Platelet-derived growth factor (PDGF)
• Vascular endothelial growth factor (VEGF)
• Transforming growth factor-β (TGF-β)
• Fibroblast growth factor (FGF)
• Epidermal growth factor
• Insulin-like growth factor (IGF-1)
Akiyama M, Smith LT, Holbrook KA. Growth factor and growth factor receptor localization in the hair follicle bulge and associated tissue in human fetus. J Invest Dermatol. 1996;106(3):391-6.
Eppley BL, Woodell JE, Higgins J. Platelet quantification and growth factor analysis from platelet-rich plasma: implications for wound healing. Plast Reconstr Surg 2004;114:1502e8.
Blair P, Flaumenhaft R. Platelet a-granules: basic biology and clinical correlates. Blood Rev 2009;23:177e89.

5. PRP mechanism of action
• GFs stimulate hair regrowth by binding to the corresponding
receptors expressed by the stem cells of the hair follicle bulge area
and surrounding tissues1,2
• After binding, the proliferative phase of the hair follicle is promoted1,2
• GFs (VEGF & PDGF) initiate pathways leading to angiogenesis and the
generation of adnexal structures3
• The secretion of VEGF by KC in ORS and fibroblasts of the dermal
papilla anagen-associated angiogenesis3
1. Akiyama M, Smith LT, Holbrook KA. Growth factor and growth factor receptor localization in the hair follicle bulge and associated tissue in human fetus. J Invest Dermatol. 1996;106(3):391-6.
2. Gkini MA, Kouskoukis AE, Tripsianis G, Rigopoulos D, Kouskoukis K. Study of platelet-rich plasma injections in the treatment of androgenetic alopecia through an one-year period. J Cutan Aesthet Surg.
2014;7(4):213-9.
3. Cervelli V, Garcovich S, Bielli A, Cervelli G, Curcio BC, Scioli MG, et al. The effect of autologous activated platelet rich plasma (AA-PRP) injection on pattern hair loss: clinical and histomorphometric
evaluation. Biomed Res Int. 2014;2014:760709.

6. PRP mechanism of action
• The cells grown with activated PRP (platelet concentration 8.8 times
higher than whole blood) showed a significantly higher rate of
proliferation on culture day 3 compared with those grown without
PRP.
Li ZJ, Choi HI, Choi DK, Sohn KC, Im M, Seo YJ, et al. Autologous platelet rich plasma: a potential
therapeutic tool for promoting hair growth. Dermatol Surg 2012;38(Pt 1):1040e6.

7. PRP mechanism of action
• Extracellular signal-regulated kinase (ERK) pathway is known to
promote cell growth.
• Activation of phosphatidylinositol 3-kinase/ protein kinase B (Akt)
signaling enhances cell survival and reduces apoptosis.
• Both in the PRP-treated dermal papilla cells relative to controls.
Li ZJ, Choi HI, Choi DK, Sohn KC, Im M, Seo YJ, et al. Autologous plateletrich plasma: a potential therapeutic tool for promoting hair growth. Dermatol
Surg 2012;38(Pt 1):1040e6.
Ito M, Yang Z, Andl T, Cui C, Kim N, Millar SE, et al. Wnt-dependent de novo hair follicle regeneration in adult mouse skin after wounding. Nature
2007;447:316e20.

8. PRP mechanism of action
• B-cell lymphoma-2 (Bcl-2), anti-apoptotic protein
• β-catenin, an important mediator of hair follicle genesis
• FGF-7, prolong the anagen phase and delay
progression to catagen.
• Shaved C57BL/6 mice
• Injected with activated PRP were able to achieve near-complete
regrowth of hair in 3 weeks
• Treated with saline exhibited only minimal regrowth.
Li ZJ, Choi HI, Choi DK, Sohn KC, Im M, Seo YJ, et al. Autologous platelet rich plasma: a potential therapeutic tool for
promoting hair growth. Dermatol Surg 2012;38(Pt 1):1040e6.

9. PRP mechanism of action
• Ki-67, a marker of cellular proliferation, identified significantly higher
levels in hair removed from pts treated with PRP1
• Growth of pigmented hairs:
• FGF-b stimulates melanin synthesis in human MC 2
• β-catenin affects melanoblast proliferation3
1. Trink A, Sorbellini E, Bezzola P, Rodella L, Rezzani R, Ramot Y, et al. A randomized, double-blind, placebo- and active-controlled, half-head study to
evaluate the effects of platelet-rich plasma on alopecia areata. Br J Dermatol. 2013;169(3):690-4.
2. Puri N, van der Weel MB, de Wit FS, Asghar SS, Das PK, Ramaiah A, Westerhof W. Basic fibroblast growth factor promotes melanin synthesis by
melanocytes. Arch Dermatol Res. 1996 Sep;288(10):633-5.
3. Luciani F, Champeval D, Herbette A, Denat L, Aylaj B, Martinozzi S, Ballotti R, Kemler R, Goding CR, De Vuyst F, Larue L, Delmas V. Biological and
mathematical modeling of melanocyte development. Development. 2011 Sep;138(18):3943-54.

10. PRP immunological mechanism of action in AA
• Monocyte chemoattractant protein-1 (MCP-1):
• β-chemokine
• + Monocyte and lymphocytes T recruitment in inflammatory conditions
• Tissue inflammation in autoimmune diseases because its tissue expression in human and experimental
autoimmune models1
• In human models of AA:
• Increased expression of MCP-1, might play a pivotal role in the attraction of monocytes around the hair
bulb2
• MCP‐1 was suppressed significantly by PRP3
• (TGF)-β is a known immunosuppressant4
1. Noris M, Bernasconi S, Casiraghi F, Sozzani S, Gotti E, Remuzzi G, Mantovani A. Monocyte chemoattractant protein-1 is excreted in excessive amounts in the urine of patients
with lupus nephritis. Lab Invest. 1995;73:804–809.
2. Benoit S, Toksoy A, Goebeler M, Gillitzer R. Selective expression of chemokine monokine induced by interferon-γ in alopecia areata. J Invest Dermatol. 2003;121:933–935
3. El-Sharkawy H, Kantarci A, Deady J, Hasturk H, Liu H, Alshahat M, Van Dyke TE. Platelet-rich plasma: growth factors and pro- and anti-inflammatory properties. J Periodontol.
2007 Apr;78(4):661-9. PubMed PMID: 17397313.
4. Amable PR, Carias RBV, Teixeira MVT, da Cruz Pacheco I, Corrêa do Amaral RJF, Granjeiro JM, et al. Platelet-rich plasma preparation for regenerative medicine: optimization and quantification of cytokines and
growth factors. Stem Cell Res Ther. 2013;4(3):67.

11. PRP Preparation
• There is no consensus on the standardized protocol for performing
PRP.
• There is no evidence-based information on type of centrifugation,
mode of activation ,yield of platelet concentration, protocol of
administration, the number of treatment sessions, and frequency of
injections1
1. Maria-Angeliki G, Alexandros-Efstratios K, Dimitris R, Konstantinos K. Platelet-rich Plasma as a Potential Treatment for Noncicatricial Alopecias. Int J Trichology.
2015;7(2):54-63.

12. PRP Preparation
• FIT PAAW acronym is suggested to help guide future studies in
reporting PRP methodologies:
(1) Force of centrifugation
(2) Iteration or sequence of centrifugation
(3) Time (duration) of centrifugation
(4) Platelet concentration from baseline
(5) Anticoagulant use
(6) Activator use and type
(7) White blood cells composition
Frautschi RS, Hashem AM, Halasa B, et al. Current evidence for clinical efficacy of platelet rich plasma in aesthetic surgery: a systematic review. Aesthet Surg J
2017;37(3):353–62

13. PRP Preparation
• Various forms of platelet-rich methodologies have been described2:
• Liquid platelet concentrate suspensions (before activation):
• Pure platelet-rich plasma (P-PRP) injectable solutions used in
• Leukocyte and platelet-rich plasma (L-PRP) hair restoration therapy
• Solid platelet concentrate biomaterials (exist only in activated form):
• Pure-platelet-rich fibrin (P-PRF) -Strong fibrin membrane/clot form
-Periodontology, oral surgery,
• Leukocyte-and platelet-rich fibrin implant dentistry, orthopedics,
(L-PRF) chronic skin ulcers
Dohan Ehrenfest DM, Sammartino G, Shibli JA, et al. Guidelines for the publication of articles related to platelet concentrates
(Platelet-Rich Plasma - PRP, or Platelet-Rich Fibrin - PRF): the international classification of the POSEIDO. POSEIDO 2013;1(1):17–
27.

14. Dohan Ehrenfest DM, Sammartino G, Shibli JA, et al. Guidelines for the publication of articles related to platelet concentrates (Platelet-Rich Plasma - PRP, or Platelet-
Rich Fibrin - PRF): the international classification of the POSEIDO. POSEIDO 2013;1(1):17–27.

16. PRP efficacy
• 5 studies + 2 case reports showed a preliminary sign of potential
effect of PRP in treating AA.

17. First report to establish the efficacy of PRP as a
treatment modality in AA

18. PRP efficacy
• 45 subjects (20 M, 25 F) with patchy chronic AA were randomized to one of
three groups:
• PRP
• Triamcinolone acetonide (TAC 2.5 mg/cc)
• Placebo
• 3 treatments with a 1 month interval.
• Method of centrifugation produced a platelet count that was on average 3.5
times higher than whole blood.
• All subjects were evaluated at baseline, 2 months, 6 months and 12 months.
• SALT score/ Dermoscopy (# dystrophic hairs)/ levels of Ki-67
Trink A, Sorbellini E, Bezzola P, Rodella L, Rezzani R, Ramot Y, et al. A randomized, double-blind, placebo- and active-controlled, half-head study
to evaluate the effects of platelet-rich plasma on alopecia areata. Br J Dermatol. 2013;169(3):690-4.

19. PRP efficacy
• Results:
• IL TAC and PRP resulted in significant hair regrowth > placebo or baseline.
• PRP showed significantly greater regrowth > TAC
• Remission rates at 12 months
• 60% PRP
• 27% TAC
• Relapse rates at 12 months
• 71% TAC
• 31% PRP
• 96% of the pts treated with PRP appeared to regrow pigmented hairs from the beginning of
hair regrowth compared with 25% of those treated with TAC.
Trink A, Sorbellini E, Bezzola P, Rodella L, Rezzani R, Ramot Y, et al. A randomized, double-blind, placebo- and active-controlled, half-head study to evaluate
the effects of platelet-rich plasma on alopecia areata. Br J Dermatol. 2013;169(3):690-4.

20. PRP efficacy
• This study supports the use of PRP in AA to stimulate hair regrowth,
especially of pigmented hairs.
• Lower chance of relapse.
• Longer disease remission.
• Platelet count that was on average 3.5 times higher than whole blood vs 8 fold
higher
• Unclear if there would be a clinical difference between these concentrations
Trink A, Sorbellini E, Bezzola P, Rodella L, Rezzani R, Ramot Y, et al. A randomized, double-blind, placebo- and active-controlled, half-head study
to evaluate the effects of platelet-rich plasma on alopecia areata. Br J Dermatol. 2013;169(3):690-4.

21. Trink A, Sorbellini E, Bezzola P, Rodella L, Rezzani R, Ramot Y, et al. A randomized, double-blind, placebo- and active-controlled, half-head
study to evaluate the effects of platelet-rich plasma on alopecia areata. Br J Dermatol. 2013;169(3):690-4.

23. PRP efficacy
• 90 pts with chronic patchy AA/AT/AU (between 10 and 40 years)
• No therapy for at least three months before study.
• 3 groups and each group includes 30 pts.
• First minoxidil 5% twice daily.
• Second 3 PRP treatment sessions every 4‐weeks.
• Third placebo.
• Digital photos and dermoscopic exam were done before treatment and monthly after treatment
for 3 months.
• Percentage of hair growth, short vellus hair and yellow dots were scaled and evaluated.
El Taieb MA, Ibrahim H, Nada EA, Seif Al-Din M. Platelets rich plasma versus minoxidil 5% in treatment of alopecia areata: A
trichoscopic evaluation. Dermatol Ther. 2017;30(1)

24. PRP efficacy
• The mean blood platelet level was 200,000 ± 75,000/μL.
• PRP
• Significant hair regrowth was noticed in patchy AA (70%)
• 30% of AU had significant regrowth
• AT did not respond.
• Minoxidil
• Improvement of patchy AA (81%)
• Ophiasis (14%)
• AT (5%)
• No hair growth was seen in AU.
• Control
• Only 30% of pts experienced a significant hair growth of patchy AA type.
El Taieb MA, Ibrahim H, Nada EA, Seif Al-Din M. Platelets rich plasma versus minoxidil 5% in treatment of alopecia areata: A trichoscopic
evaluation. Dermatol Ther. 2017;30(1)

25. PRP efficacy
• PRP showed a significant decrease in short vellus hair, yellow dots, and
dystrophic hair .
• Minoxidil and control showed significant increase in mean number of short
vellus hairs.
• PRP had better, an earlier response with significant fully pigmented hair
growth than minoxidil
• This study supports the use of PRP in AA to stimulate hair regrowth,
especially of pigmented hairs.
• Short F/U duration (3 months) precludes assessment of relapse rates.
El Taieb MA, Ibrahim H, Nada EA, Seif Al-Din M. Platelets rich plasma versus minoxidil 5% in treatment of alopecia areata: A
trichoscopic evaluation. Dermatol Ther. 2017;30(1)

26. El Taieb MA, Ibrahim H, Nada EA, Seif Al-Din M. Platelets rich plasma versus minoxidil 5% in treatment of alopecia areata: A trichoscopic
evaluation. Dermatol Ther. 2017;30(1)

28. PRP efficacy
• 74 pts with mild AA (25% or less involvement).
• 2 groups
• 1st group = 48 pt who received TAC 10mg/ml
• 2nd group = 26 pt that underwent PRP injections.
• PRP was prepared with a double centrifugation technique. 10% calcium
chloride was added as an activator (0.3 ml for 1ml PRP).
• A total of 3 treatments on 3 weeks interval.
• Patients were evaluated at 3 months by '' assessment of overall
improvement'' scale, serial photographs and dermoscopic examination.
Shumez H, Prasad, P.V.S., Kaviarasan, P.K., and Deepika, R. Intralesional platelet rich plasma vs intralesional
triamcinolone in the treatment of alopecia areata: a comparative study. Int J Med Res Health Sci. 2015;4:118-22

29. PRP Efficacy
• By week 6, remission was achieved by 52.8% of those treated with
PRP and 35.4% of the TAC group, but this difference was not
statistically significant.
• This study evaluated AA patients with less than 25% scalp
involvement.
• Patients with limited scalp involvement may be more likely to
undergo spontaneous remission of their disease, which could also
have affected the results in this study.
Shumez H, Prasad, P.V.S., Kaviarasan, P.K., and Deepika, R. Intralesional platelet rich plasma vs intralesional triamcinolone in the
treatment of alopecia areata: a comparative study. Int J Med Res Health Sci. 2015;4:118-22

30. Shumez H, Prasad, P.V.S., Kaviarasan, P.K., and Deepika, R. Intralesional platelet rich plasma vs intralesional triamcinolone in the treatment of alopecia areata: a
comparative study. Int J Med Res Health Sci. 2015;4:118-22

32. PRP Efficacy
• 20 pts with chronic AA (severity unknown) that had been unsuccessfully
treated for at least 2 years.
• All pts received 6 PRP sessions at 4 weeks interval.
• ? PRP preparation.
• Pts evaluated monthly for 6 months and at 1 year.
• At 1 year:
• PRP > well tolerated
• Relapse > in only one pt
• This study did not report how patient response to treatment was
established.
Singh S. Role of platelet-rich plasma in chronic alopecia areata: Our centre experience. Indian J Plast Surg. 2015;48(1):57-9.

33. Singh S. Role of platelet-rich plasma in chronic alopecia areata: Our centre experience. Indian J Plast Surg. 2015;48(1):57-9.

34. (a) Pre-intervention state of the patient with alopecia areata (b) post-platelet rich plasma (PRP) status-note the improved
hair growth at the end of 6 months (c) post-PRP status-note the relapse at the end of 1 year
Singh S. Role of platelet-rich plasma in chronic alopecia areata: Our centre experience. Indian J Plast Surg. 2015;48(1):57-9.

36. PRP Efficacy
• Case report of 41 years old lady with AA (ophiasis type) for 2 years
that have failed IL TAC.
• PRP mixed with platelet poor plasma to achieve a final platelet
concentration of 3.5 times above baseline.
• A total of 9 ml of PRP was injected.
• Hair regrowth started 1 month after procedure with significant
regrowth by month 3.
• Ophiasis type AA is often more recalcitrant to treatment and this
reported success suggests the potential for PRP use among this
population.
Donovan J. Successful treatment of corticosteroid-resistant ophiasis-type alopecia areata (AA) with platelet-rich plasma (PRP). JAAD Case Rep. 2015;1(5):305-7

37. Donovan J. Successful treatment of corticosteroid-resistant ophiasis-type alopecia areata (AA) with platelet-rich plasma (PRP). JAAD Case Rep. 2015;1(5):305-7

39. Mubki T. Platelet-rich plasma combined with intralesional triamcinolone acetonide for the treatment of alopecia areata: a case report. J Dermatol Dermatol Surg.
2016;20:87-90.
PRP Efficacy
• Case report of 22 y/o pt with chronic diffuse AA who had been treated
unsuccessfully with multiple treatment modalities including topical
corticosteroids, minoxidil, and anthralin.
• Right side of the scalp
• Both IL TCA (2.5 mg/ml a total of 4 ml) and intradermal injections of PRP (2-3 ml).
• 4 sets of PRP alternating with 4 sessions of intralesional TCA at 2 weeks interval
during 16 weeks.
• Left half of the scalp
• IL TCA only (2.5 mg/ml a total of 4 ml). Total of 4 sessions.
• PRP containing ACD-A (trisodium citrate, citric acid and dextrose).
• The PRP fraction was separated and activated with calcium chloride.

40. Mubki T. Platelet-rich plasma combined with intralesional triamcinolone acetonide for the treatment of alopecia areata: a case
report. J Dermatol Dermatol Surg. 2016;20:87-90.

41. Mubki T. Platelet-rich plasma combined with intralesional triamcinolone acetonide for the treatment of alopecia areata: a case report. J Dermatol
Dermatol Surg. 2016;20:87-90.

43. Limited Efficacy of PRP
• Case series of 9 pts with chronic AA (> 50% of the scalp involved)1
• 3 PRP sessions with 45-60 days interval.
• Protocol for PRP preparation was almost similar to the study of Trink et al2
• Total of 2-4 ml PRP were injected intradermally.
• The pts were evaluated at baseline, 8 months and 1 year.
• At 8th month
• 6 pts > re-growth of terminal pigmented hair
• 3 pts > nonpigmented vellus in the seats of infiltration after 2nd session of PRP.
• At 1 year, all pts had relapse.
1. d'Ovidio R RM. Limited effectiveness of platelet-rich-plasma treatment on chronic severe alopecia areata. Hair Ther Transplant. 2014;4(1):116.
2. Trink A, Sorbellini E, Bezzola P, Rodella L, Rezzani R, Ramot Y, et al. A randomized, double-blind, placebo- and active-controlled, half-head study to evaluate the
effects of platelet-rich plasma on alopecia areata. Br J Dermatol. 2013;169(3):690-4.

44. Donovan J. Successful treatment of corticosteroid-resistant ophiasis-type alopecia areata (AA) with platelet-rich plasma (PRP). JAAD Case Rep.
2015;1(5):305-7
Badran KW, Sand JP. Platelet-Rich Plasma for Hair Loss: Review of Methods and Results. Facial Plast Surg Clin North Am. 2018;26(4):469-85.
PRP Side Effects
• PRP procedure is a relatively effective and safe intervention with
minimal adverse effects including
• Temporary and tolerable pain, and pinpoint bleeding during treatment
• Mild headache which may regress with paracetamol
• Minimal itching / scalp sensitivity
• Transient erythema, edema, and desquamation
• Uncommon telogen effluvium

45. 1. Valente Duarte de Sousa IC, Tosti A. New investigational drugs for androgenetic alopecia. Expert Opin Investig Drugs 2013;22(5):573–89.
2. Trink A, Sorbellini E, Bezzola P, Rodella L, Rezzani R, Ramot Y, et al. A randomized, double-blind, placebo- and active-controlled, half-head study
to evaluate the effects of platelet-rich plasma on alopecia areata. Br J Dermatol. 2013;169(3):690-4.
PRP Side Effects
• Unpublished anecdotal report of 3 patients developed TE with
psoriasiform scalp dermatitis 2 to 6 weeks after being treated with PRP
were seen by Dr. Tosti1
• No reports of infections, folliculitis, panniculitis, hematoma, or seroma
formation.
• Pts who received PRP in Trink et al. study actually demonstrated
reduction of burning/itching compared with baseline2

46. PRP Contraindications
• Platelet dysfunction
• Thrombocytopenia
• Coagulation disorders
• Anticoagulant therapy
• Hemodynamic instability
• Local infection at the site of blood harvest or PRP injection
• Pts who are prone to keloid formation
Badran KW, Sand JP. Platelet-Rich Plasma for Hair Loss: Review of Methods and Results. Facial Plast Surg Clin North Am. 2018;26(4):469-85.

47. Summary
• There is a preliminary evidence supporting PRP for the treatment of
AA.
• Lacking of standardized protocol precludes any recommendations for
the number of PRP sessions required to treat and maintain AA.
• PRP is relatively safe and potentially effective to regrow pigmented
hairs in AA.
• Further large-scale studies are needed to evaluate the efficacy of PRP
procedure as monotherapy and whether it is superior over current
therapeutic modalities for AA.

48. References
• DelRossi AJ, Cernaianu AC, Vertrees RA, Wacker CJ, Fuller SJ, Cilley JH, Jr., et al. Platelet-rich plasma reduces postoperative blood loss after
cardiopulmonary bypass. J Thorac Cardiovasc Surg. 1990;100(2):281-6.
• Cieslik-Bielecka A, Choukroun J, Odin G, Dohan Ehrenfest DM. L-PRP/L-PRF in esthetic plastic surgery, regenerative medicine of the skin and chronic
wounds. Curr Pharm Biotechnol. 2012;13(7):1266-77.
• Albanese A, Licata ME, Polizzi B, Campisi G. Platelet-rich plasma (PRP) in dental and oral surgery: from the wound healing to bone regeneration.
Immun Ageing. 2013;10(1):23.
• Albanese A, Licata ME, Polizzi B, Campisi G. Platelet-rich plasma (PRP) in dental and oral surgery: from the wound healing to bone regeneration.
Immun Ageing. 2013;10(1):23.
• Arshdeep, Kumaran MS. Platelet-rich plasma in dermatology: boon or a bane? Indian J Dermatol Venereol Leprol. 2014;80(1):5-14.
• Schiavone G, Raskovic D, Greco J, Abeni D. Platelet-rich plasma for androgenetic alopecia: a pilot study. Dermatol Surg. 2014;40(9):1010-9.
• Eppley BL, Woodell JE, Higgins J. Platelet quantification and growth factor analysis from platelet-rich plasma: implications for wound healing. Plast
Reconstr Surg 2004;114:1502e8.
• Li ZJ, Choi HI, Choi DK, Sohn KC, Im M, Seo YJ, et al. Autologous plateletrich plasma: a potential therapeutic tool for promoting hair growth. Dermatol
Surg 2012;38(Pt 1):1040e6.
• Ito M, Yang Z, Andl T, Cui C, Kim N, Millar SE, et al. Wnt-dependent de novo hair follicle regeneration in adult mouse skin after wounding. Nature
2007;447:316e20.
• Arshdeep, Kumaran MS. Platelet-rich plasma in dermatology: boon or a bane? Indian J Dermatol Venereol Leprol. 2014;80(1):5-14.
• Akiyama M, Smith LT, Holbrook KA. Growth factor and growth factor receptor localization in the hair follicle bulge and associated tissue in human fetus.
J Invest Dermatol. 1996;106(3):391-6.

49. References
• Gkini MA, Kouskoukis AE, Tripsianis G, Rigopoulos D, Kouskoukis K. Study of platelet-rich plasma injections in the treatment of androgenetic alopecia
through an one-year period. J Cutan Aesthet Surg. 2014;7(4):213-9.
• Cervelli V, Garcovich S, Bielli A, Cervelli G, Curcio BC, Scioli MG, et al. The effect of autologous activated platelet rich plasma (AA-PRP) injection on
pattern hair loss: clinical and histomorphometric evaluation. Biomed Res Int. 2014;2014:760709.
• Maria-Angeliki G, Alexandros-Efstratios K, Dimitris R, Konstantinos K. Platelet-rich Plasma as a Potential Treatment for Noncicatricial Alopecias. Int J
Trichology. 2015;7(2):54-63.
• Lynch MD, Bashir S. Applications of platelet-rich plasma in dermatology: A critical appraisal of the literature. J Dermatolog Treat. 2016;27(3):285-9.
• Trink A, Sorbellini E, Bezzola P, Rodella L, Rezzani R, Ramot Y, et al. A randomized, double-blind, placebo- and active-controlled, half-head study to
evaluate the effects of platelet-rich plasma on alopecia areata. Br J Dermatol. 2013;169(3):690-4.
• El Taieb MA, Ibrahim H, Nada EA, Seif Al-Din M. Platelets rich plasma versus minoxidil 5% in treatment of alopecia areata: A trichoscopic evaluation.
Dermatol Ther. 2017;30(1).
• Shumez H, Prasad, P.V.S., Kaviarasan, P.K., and Deepika, R. Intralesional platelet rich plasma vs intralesional triamcinolone in the treatment of alopecia
areata: a comparative study. Int J Med Res Health Sci. 2015;4:118-22.
• Singh S. Role of platelet-rich plasma in chronic alopecia areata: Our centre experience. Indian J Plast Surg. 2015;48(1):57-9.
• Donovan J. Successful treatment of corticosteroid-resistant ophiasis-type alopecia areata (AA) with platelet-rich plasma (PRP).
JAAD Case Rep. 2015;1(5):305.
• Mubki T. Platelet-rich plasma combined with intralesional triamcinolone acetonide for the treatment of alopecia areata: a case report. J Dermatol Dermatol
Surg. 2016;20:87-90.
• d'Ovidio R RM. Limited effectiveness of platelet-rich-plasma treatment on chronic severe alopecia areata. Hair Ther Transplant. 2014;4(1):116.
• Badran KW, Sand JP. Platelet-Rich Plasma for Hair Loss: Review of Methods and Results. Facial Plast Surg Clin North Am. 2018;26(4):469-85.