Letter in response to “The effectiveness of adding low-level light therapy to minoxidil 5% solution in the treatment of patients with androgenetic alopecia”

Deepthi Malayanur, Venkataram Mysore

 Department of Dermatology, Venkat Center for Skin and Plastic Surgery, Institute for Advanced Dermatology and Postgraduate Training, Bengaluru, Karnataka, India

Correspondence Address:
Deepthi Malayanur
Department of Dermatology, Venkat Center for Skin and Plastic Surgery, Institute for Advanced Dermatology and Postgraduate Training, Bengaluru, Karnataka
India

Sir,

We have read with keen interest the article on “The effectiveness of adding low-level light therapy to minoxidil 5% solution in the treatment of patients with androgenetic alopecia” by Faghihi et al.^[1] We would like to seek some clarifications from the authors on the following points:

1. In the study, the authors used 20 drops of minoxidil 5% lotion twice daily equivalent to 2 mL twice daily in both control and case groups. The recommended dosage of minoxidil is 1 mL twice daily. The authors did not mention why twice the volume of recommended dosage of minoxidil 5% lotion was used.
2. Furthermore, the study included female patients. However, the authors did not mention whether the same dosage of 20 drops twice daily was given to all female patients like male patients. In women, the dosage of 2 mL twice daily is unacceptable as it may lead to adverse effects such as hirsutism in females with such high dosage.
3. In the study, the authors performed hair counts using trichogram at months 0 (i.e., at the beginning of the study), 3, 6, 9, and 12. However, the authors did not mention how the trichogram site was selected at each subsequent visit for uniformity in estimation.
4. The authors mentioned that they used hair counts for assessment of results but did not mention global photography which is a standard technique for assessing hair growth.
5. In the study, the authors mentioned that the treatment was given for 6 months only, and the mean hair count was significantly higher at 9 and 12 months after the intervention in the case group compared with the control group. Also, the mean hair diameter was significantly higher in the cases compared with the controls only 12 months after the intervention and not before. It is difficult to understand why improvement must happen 3–6 months after stopping treatment as this has not been reported in earlier studies which reported improvement during the treatment.^[2],[3] Second, it is normally expected that hair diameter improves faster and counts take longer time to improve. On the contrary, in this study, hair count improved at 9 months and diameter improved at 12 months.

We request the authors to clarify these issues.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

1.	Faghihi G, Mozafarpoor S, Asilian A, Mokhtari F, Esfahani AA, Bafandeh B, et al. The effectiveness of adding low-level light therapy to minoxidil 5% solution in the treatment of patients with androgenetic alopecia. Indian J Dermatol Venereol Leprol 2018;84:547-53. [Google Scholar]
2.	Lanzafame RJ, Blanche RR, Bodian AB, Chiacchierini RP, Fernandez-Obregon A, Kazmirek ER. The growth of human scalp hair mediated by visible red light laser and LED sources in males. Lasers Surg Med 2013;45:487-95. [Google Scholar]
3.	Lanzafame RJ, Blanche RR, Bodian AB, Chiacchierini RP, Kazmirek ER, Sklar JA. The growth of human scalp hair in females using visible red light laser and LED sources. Lasers Surg Med 2014;46:601-7. [Google Scholar]