April 2020 HSC Section 4 - Plastic and Reconstructive Problems

Aesth Plast Surg

6-month follow-up, the pull test was negative in 83% of the PRP group patients but positive in all the subjects in the control group. Rodrigues [ 15 ] compared with the baseline and 15 days after the last injections, the anagen percentage was significantly increased in the PRP group. However, at 3 months after the last injections, this result was not maintained, and the control group showed no significant increase at any of the evaluated time points. A histological or immunohistochemisty examination was performed in 5 studies [ 5 – 8 , 12 ] to evaluate the

histological changes under subcutaneous injection of PRP. All of the authors agreed that compared with a control treatment, the injection of PRP made the epidermis thicker, collagen fibers and fibroblasts proliferate, and the number of hair follicles and blood vessels around these fibers increase; in addition, immunohistochemisty showed an increase in Ki67 ? basal keratinocytes of the epidermis and of hair follicular bulge cells when compared with baseline, indicating cell proliferation of the hair skin.

Fig. 2 Risk of bias among controlled clinical trials

Fig. 3 Forest plot showing the increased hair density compared with control

Fig. 4 Funnel plot for bias assessment in hair density increase

123

105