Assessment of efficacy of different botulinum toxin A concentrations in the treatment of androgenetic alopecia assessed by dermoscopy.

[BACKGROUND] Androgenetic alopecia (AGA) is the most common type of progressive hair loss in men and women. AGA is characterized by the miniaturization of the hair follicle, leading to the transformation of terminal hair to vellus hair.

[OBJECTIVE] To evaluate the efficacy and safety of injecting two different concentrations of botulinum toxin A (BTA) for the treatment of AGA in Egyptian patients.

[METHODS] Adult male (Hamilton-Norwood I-VII) and female (Ludwig I-III) patients (N = 32) were assigned to receive two different concentrations BTA (33.3 and 25 U/mL) on each side of the scalp; in total, there were 15 injections administered on each side, with injection volume of 0.1 mL containing 3.3 U for the right half and 2.5 U for the left half. Treatment efficiency was assessed at baseline, Month 3 and Month 6, by degree of clinical improvement and dermoscopy assessment.

[RESULTS] By Month 6, proportion of male patients (N = 5) classified as Hamilton-Norwood Grade II increased from 0% to 60% (3/5), proportion of female patients (N = 27) classified as Ludwig Grade I also increased from 14.8% (4/27) to 70% (19/27). Dermoscopy result showed a significant increase in vellus hair density from baseline to Month 6 on the right side (33.3 U/mL), while no change was observed on the left (25 U/mL); however, vellus hair density was higher at Month 3 compared to Month 6. There were changes in yellow spots and peripilar sign more on the right side. Adverse reactions reported include irritation, headache, injections site pain, and nausea.

[CONCLUSION] The results of the present study showed that BTA is a safe and effective treatment for AGA in both genders. These findings offer a cutting-edge conceptual structure and therapeutic strategy for the management of AGA in Egyptian population.