Journal of

Platelet-rich plasma (PRP) is a solution derived from whole blood that is enriched in the platelet fraction. Platelets serve as a reservoir of growth factors and cytokines. When platelets are activated in vivo, signaling molecules are released into the immediate microenvironment and activate receptors for various pathways. PRP has been applied to bedsores to promote healing. Over the last decade, it has been used as a valuable therapeutic method in various specialties such as maxillofacial surgery, plastic surgery, orthopedics and sports medicine. Only recently has PRP been utilized for dermatologic purposes, psrticularly, for the treatment of male and female pattern hair loss.

In this review, we discuss molecular and cellular pathways up-regulated by PRP important in hair folliculogenesis, and examine clinical evidence from all previously published studies involving the use of PRP for pattern hair loss.

Background and Aim: Hair loss is one of the most common problems among the skin and hair related diseases. Hair loss can lead to anxiety, depression, low self-esteem and dissatisfaction with appearance.
 

Methods: Patients with androgenetic alopecia who met the eligibility criteria entered the study. Participants were asked to randomly apply a solution of valproic acid 8.3% or a solution of minoxidil 5% on the affected areas according to the treatment protocol (twice a day). Before and 2 months after treatment, the participants were evaluated. The studied indices included the number of hair follicles in the specified area, the number of velus hairs, the number of terminal hairs, the average hair thickness, and the percentage of hairs in the anagen and telogen phases, as well as the skin reactions in the area. Hairs were examined at the beginning of the study and at 2 months after treatment using Foto Finder-trichoscale device.
 

Results: Two months after treatment compared to baseline in the valproic group, anagen hair count index (P=0.02), general hair count index (P=0.03), and terminl hair count index (P=0.012) showed significant changes. While telogen hair count (P=0.059) and vellus hair count (P=0.097) did not show significant changes. These changes were more significated in minoxidil group.

Conclusion: 8.3% valproic acid solution showed positive effects in increasing the number of hairs and decreasing the percentage of telogen hairs. Due to the delayed mechanism of valproic acid, the duration of treatment with this compound should be considered longer than minoxidil as a positive control.