Optical coherent tomography for in vivo determination of changes in hair cross section and diameter during treatment with glucocorticosteroids--a simple method to screen for doping substances?

Eighty percent of hair follicles are in the growing phase. They grow approximately 0.3 mm/day. The hair follicles are surrounded by a close network of capillaries, which supplies them with nutrients. It is well known that substances which influence the metabolic processes of humans also influence hair growth. Steroids, which are used for doping in sport, are among these substances. In the present paper, optical coherent tomography is used for the analysis of changes in the hair structure during the application of steroids for the treatment of patients suffering from auto-immune diseases. Significant differences in the hair cross section could be detected during treatment, while the shape of the hairs was not influenced. It could be demonstrated that optical coherence tomography is a suitable, non-invasive and low-cost measuring technique that can be applied for doping control and screening. As a result of this screening process, only those athletes who show abnormalities in hair parameters would need to be investigated by classical analytical methods. The results presented in this study are not only important for doping controls, but also for several clinical applications, such as therapy and compliance control in cases where the applied substances induce changes in the hair structure.