At this current point in time, there are no new drugs in the management of vitiligo 😔. JAK inhibitors are around the corner, but they are still a fair way off coming to the UK and being prescribed in mainstream dermatology practice.
It was therefore interesting to read in the May online edition of the British Journal of Dermatology of a group in South Korea (Republic of Korea) who had performed a nationwide, population-based study looking at the use of a common anti-Parkinson’s drug and the development of vitiligo.
[Jung MB, Kim M, Han JH et al. Preventive effect of levodopa on vitiligo development: a nationwide case control study. Br J Dermatol 2022; doi: 10.1111/bjd.21054]
Why were they looking at an anti-Parkinson’s drug and vitiligo?
Yes, it sounds bizarre, doesn’t it?
Basically, the science behind it is that levodopa, a commonly used drug to treat patients with Parkinson’s disease is a precursor of two chemicals naturally found in the body, namely dopamine (hence its benefit in the treatment of Parkinson’s) and also melanin (the chemical responsible for the pigment levels in our skin).
There have been some reports of stimulation of melanin production in patients on levodopa and also darkening of hair after levodopa therapy.
[Bougea A, Spantideas N, Katoulis A et al. Levodopa-induced skin disorders in patients with Parkinson disease: a systematic literature review approach. Acta Neurol Belg 2019;119:325-36.]
[Komagamine T, Suzuki K, Hirata K. Darkening of white hair following levodopa therapy in a patient with Parkinson’s disease. Mov Disord 2013;28:1643.]
What did they look at?
They looked at almost 56,000 patients aged over 40y with newly developed vitiligo who had visited a doctor at least four times between 2007 and 2017. Levodopa use before the first date of diagnosis of vitiligo was identified. This was compared to individuals who had no diagnosis of vitiligo.
What did they find?
They found that prior levodopa use was negatively associated with vitiligo development and this was most pronounced if the levodopa use was for longer than 6 months, ie those who had been prescribed levodopa were less likely to be diagnosed with vitiligo.
That’s brilliant! So why can’t we just prescribe levodopa for vitiligo patients?
It’s not that simple. Further studies are needed looking at levodopa use specifically in patients with vitiligo. This study from South Korea only identified levodopa prescribing in 231 control patients (ie no vitiligo) and 185 (0.33%) patients with vitiligo out of the total 56,000 patients.
Also, more worryingly, other large literature review studies have identified that malignant melanoma was the most frequent oral levodopa-related skin disorder. The authors of that paper, however, found that evidence at the time did not support an association between levodopa treatment and the induction or progression of malignant melanoma and advised caution in interpreting their results 🤓.
[Bougea A, Spantideas N, Katoulis A et al. Levodopa-induced skin disorders in patients with Parkinson disease: a systematic literature review approach. Acta Neurol Belg 2019;119:325-336.]
Dr Sandy Flann, Consultant Dermatologist.