Table I.
Characteristics and main results of the included studies on the use of platelet-rich plasma in alopecia
| Study (year)ref | Study design | N. of patients (condition) | Male/female | Age in years (range) | Test group (N) | Control group (N) | Outcomes | Follow-up | Main results |
|---|---|---|---|---|---|---|---|---|---|
| Trink (2013) 43 | RCT, split-head design | 45 (AA) | - | - | ILC (15) PRP (15) |
Placebo (15) | Hair regrowth; SALT score; dermoscopic evaluation | 1 year | PRP increased hair regrowth significantly and decreased hair dystrophy |
| Cervelli (2014) 44 | RCT, split-head design | 10 (AA) | 10/0 | 22–60 | PRP (10) | Placebo (10) | Total hair counts; hair density; terminal and vellus hair densities | 6 months | A clinical improvement in mean hair count and mean hair thickness for the PRP group |
| Gentile (2015) 45 | RCT, split-head design | 20 (AGA) | 20/0 | 19–63 | PRP (20) | Placebo (20) | Hair count; hair density; terminal hair density; vellus hair density, microscopic evaluation | 2 years | A significant increase in the mean hair count and terminal hair density for the PRP group |
| Lee (2015) 46 | RCT | 40 (AGA) | 0/40 | 20–60 | PRP + PDRN (20) | PDRN (20) | Hair counts; mean hair thickness | 3 months | PRP + PDRN induced greater improvement in hair thickness than treatment with PDRN therapy alone |
| Mapar (2016) 47 | RCT, split-head design | 17 (AGA) | 17/0 | 25–45 | PRP (17) | Placebo (17) | Terminal and vellus hairs | 6 months | PRP did not improve hair growth |
| Puig (2016) 48 | Non-RCT | 26 (AGA) | 0/26 | - | PRP (15) | Placebo (11) | Hair count; hair mass index; patient-opinion survey | 26 weeks | No statistically significant difference between the two groups |
| Alves (2016) 49 | RCT | 25 (AGA) | 12/13 | 18–65 | PRP (25) | Placebo (25) | Hair count; hair density; terminal hair density | 6 months | A statistically significant increase in mean total hair density for the PRP group |
| El Taieb (2017) 50 | RCT | 90 (AA) | 39/51 | 10–40 | Topical minoxidil 5% (30), PRP (30) | Placebo (30) | Hair growth; dermoscopic evaluation | 3 months | An earlier response in the form of hair regrowth, reduction in short vellus hair and dystrophic hair in the PRP group |
| Shah (2017) 51 | RCT | 50 (AGA) | - | 18–50 | PRP + MN + topical minoxidil 5% (25) | Topical minoxidil 5% (25) | Dermoscopic evaluation | 6 months | A significant improvement in the PRP group |
| Toama (2017) 52 | RCT | 40 (AGA) | 19/21 | 18–45 | PRP (20) | Placebo (20) | Hair count; clinical evaluation; side effects | 6 months | A greater mean number of hairs in the PRP group |
| Kachhawa (2017) 53 | RCT, split-head design | 44 (AGA) | 44/0 | 18–55 | PRP (44) | Placebo (44) | Hair growth; dermoscopic evaluation | 6 months | A significant increase in mean hair thickness/density for the PRP group |
| Tawfik (2017) 54 | RCT, split-head design | 30 (AGA) | 0/30 | 20–45 | PRP (30) | Placebo (30) | Hair density, hair diameter, patient’s satisfaction | 6 months | PRP significantly increased hair density and hair thickness |
| Behrangi (2019) 55 | RCT | 114 (AGA) | 114/0 | 20–40 | Finasteride (28), PRP (26) | Placebo (60) | Hair growth; reduction of hair loss | 6 months | A statistically significant increase in hair growth and hair loss reduction in the PRP group |
| Ranparija (2019) 56 | RCT, split-head design | 30 (AA) | 22/8 | 20–40 | PRP (30) | ILC (30) | Hair regrowth | 3 months | A significant increase in hair regrowth for ILC treatment |
| Rodrigues (2019) 57 | RCT | 26 (AGA) | 26/0 | 18–50 | PRP (15) | Placebo (11) | Hair count; hair density | 2 months | PRP significantly increased hair growth |
| Verma (2020) 58 | Non-RCT | 40 (AGA) | 40/0 | 20–49 | PRP (20) | Topical minoxidil 5% (20) | Hair pull test; hair growth questionnaire; patient’s satisfaction | 6 months | PRP was found to be better than topical minoxidil therapy |
| Albalat (2019) 59 | RCT | 80 (AA) | 68/12 | 17–52 | PRP (40) | ILC (40) | RGS; dermoscopic evaluation; side effects | 6 months | No statistically significant difference between the two groups |
| Aggarwal (2020) 60 | RCT, split-head design | 30 (AGA) | 30/0 | 22–44 | MN + PRP (30) | MN (30) | Hair thickness; hair density; satisfaction score | 3 months | No additional effect in MN + PRP-treated group |
| Balakrishnan (2020) 61 | Non-RCT | 32 (AA) | - | - | PRP (16) | ILC (16) | SALT score; RGS | 12 weeks | No statistically significant difference between the two groups |
| Shapiro (2020) 62 | RCT, split-head design | 35 (AGA) | 18/17 | 18–58 | PRP (35) | Placebo (35) | Hair density; hair diameter; patient’s satisfaction; side effects | 3 months | No significant difference in hair density change between the two groups |
| Dubin (2020) 63 | RCT | 28 (AGA) | 0/28 | 27–85 | PRP (14) | Placebo (14) | Hair density; dermoscopic evaluation; side effects | 24 weeks | A statistically significant increase in mean total hair density for the PRP group |
| Kapoor (2020) 64 | RCT | 40 (AA) | 18/22 | 18–50 | PRP (20) | ILC (20) | SALT score, patient’s satisfaction | 6 months | Reduction in SALT score was greater in the ILC group |
| Hegde (2020) 65 | RCT, split-head design | 50 (AA) | - | 18–60 | PRP (25), ILCs (25) | Placebo (25) | SALT score; dermoscopic evaluation | 5 months | The maximum absolute regrowth occurred in the steroid group followed by the PRP group followed by the placebo group |
| Gressemberger (2020) 66 | RCT | 28 (AGA) | 28/0 | 18–52 | PRP (28) | Placebo (28) | Hair growth; clinical improvement; patient’s satisfaction | 6 months | PRP did not improve hair growth |
| Singh (2019) 67 | RCT | 80 (AGA) | 80/0 | 18–60 | Topical minoxidil 5% (20) PRP (20) PRP + topical minoxidil 5% (20) |
Placebo (20) | Hair density, dermoscopic evaluation | 5 months | PRP with topical minoxidil was the most effective treatment modality while PRP alone and topical minoxidil alone were more effective than placebo |
| Gupta (2021) 68 | RCT, split-head design | 27 (AA) | 13/14 | 18–35 | PRP (27) | Placebo (27) | SALT score; dermoscopic evaluation; side effects | 3 months | PRP showed limited efficacy vs placebo |
| Farid (2016) 69 | RCT | 40 (AGA) | 9/31 | 20–40 | PRP + MN (20) | Topical minoxidil 5% (20) | Hair count; patient’s satisfaction; adverse events | 28 weeks | A statistically comparable efficacy of daily application of 5% topical minoxidil versus PRP + MN |
AGA: androgenetic alopecia; AA: alopecia areata; PRP: platelet-rich plasma; RCT: randomised controlled trial; MN: microneedling; ILC: intralesional corticosteroids; PDRN: polydeoxyribonucleotide injection; RGS: re-growth scale; SALT score: severity of alopecia tool score.