Botulinum Toxin Type A Effective for Androgenetic Alopecia

[whatintheworld]

Effectiveness and Safety of Botulinum Toxin Type A in the Treatment of Androgenetic Alopecia

<i>Background</i>. Androgenetic alopecia (Androgenetic Alopecia) represents the most frequent clinical complaint encountered by dermatologists and is characterized by a progressive miniaturization of the hair follicle. However, the efficacy and safety of current medical treatment remain limited, and more...

www.hindawi.com

Abstract​

Background
Androgenetic alopecia (Androgenetic Alopecia) represents the most frequent clinical complaint encountered by dermatologists and is characterized by a progressive miniaturization of the hair follicle. However, the efficacy and safety of current medical treatment remain limited, and more personalized therapeutic approaches for Androgenetic Alopecia are needed. Therefore, the present study is aimed at investigating the efficacy and safety of botulinum toxin type A (BTA) in patients with Androgenetic Alopecia.

Methods
63 patients with Androgenetic Alopecia meeting the inclusion criteria were included in this study and treated with BTA injection or BTA injection combined with oral finasteride (FNS). In the scalp, 30 sites were injected with 100 U of BTA in each site and patients received BTA after every 3 months for a total of 4 times. Hair counts, head photographs, evaluation scores, and self-assessment were assessed in patients with Androgenetic Alopecia.

Results
Hair counts in both groups at all time points were significantly higher as compared with those before treatment. After 4 times of treatment, hair counts in the BTA+FNS group were higher than those in the BTA group. Hair growth and density were significantly augmented, and the area of hair loss was attenuated after each treatment as revealed by head photographs. The effective rates of BTA and BTA+FNS groups were 73.3% and 84.8%, respectively, following 4 times treatment.

Conclusion
BTA is a safe and effective therapeutic strategy for the treatment of Androgenetic Alopecia without adverse effects, and BTA combined with FNS exhibited a superior therapeutic effect than BTA alone.

Important thing to note:
Botulinum toxin is one of the highly effective neurotoxins produced by the bacterium Clostridium botulinum. BTA prevents the release of acetylcholine and many other neurotransmitters at the presynaptic neuromuscular junction [22]. BTA has been extensively used in the dermatology clinic for wrinkle reduction, facial muscle adjustment, hyperhidrosis, correction of masseter hypertrophy, and gastrocnemius hypertrophy. Besides, long-term effects of muscles surrounding the affected scalp (including the frontal, occipital, periauricular, and temporal muscles) tighten the affected scalp, resulting in reduced blood flow to the terminal vessels at the top of the head and forehead, which eventually leads to a hypoxic state in these affected areas [23]. Moreover, DHT is prone to activation under hypoxic conditions, and it is the most crucial factor that terminates hair follicles and causes hair loss. Previous studies suggested that there were hemodynamic abnormalities including microvascular dysfunction and reduced blood flow in the alopecia region of Androgenetic Alopecia patients [24]. Therefore, improving the scalp blood supply may stimulate hair growth. Possibly, BTA may relax the muscles around the head, increase blood flow and oxygen concentration in the alopecia area, and further inhibit the activation of DHT, ultimately leading to a reduced occurrence of hair loss. Moreover, a high concentration of oxygen can stimulate the hair follicle into the growth phase, resulting in hair regeneration [25–27].