The role of sleep in telogen effluvium and trichodynia: A commentary in the context of the current pandemic.

Telogen effluvium (TE), a common hair disease, is supposed to be related to stress, which could be secondary to poor sleep. We call attention to the current COVID-19 pandemic, that is leading to an increase in the prevalence of sleep disturbances, and as a consequence, higher states of stress and anxiety, which are possible triggers for TE. In parallel, trichodynia is a sensorial symptom that is commonly related with hair diseases, including TE. We argue that substance P, a neuropeptide that has participation in the neuroinflammation and in the sleep regulation, may play a possible role in this scalp paresthesia. We suggest that there may be an association between this substrate and sleep, which can aggravate trichodynia and TE. Further studies on this subject could provide more evidence on these relationships, and help to improve the patients' quality of life and management of the condition.