Reply to: "Comment on 'Androgenetic alopecia present in the majority of patients hospitalized with COVID-19'"

The clinical and immunological features of alopecia areata following SARS-CoV-2 infection or COVID-19 vaccines

INTRODUCTION

Alopecia areata (AA) is an autoimmune disease induced by viral infection or vaccination. With the increased incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the incidence of AA has also increased. Recently the incidence was found to be 7.8% from a previously reported rate of 2.1%. The physical and psychological damage caused by AA could seriously affect patients' lives, while AA is a challenging dermatological disease owing to its complex pathogenesis.

AREAS COVERED

This paper presents a comprehensive review of the prevalence, pathogenesis and potential therapeutic targets for AA after infection with SARS-CoV-2 or SARS-CoV-2 vaccine.

EXPERT OPINION

The treatment of AA remains challenging because of the complexity of its pathogenesis. For patients with AA after SARS-CoV-2 infection or vaccination, the use of sex hormones and alternative regenerative therapies may be actively considered in addition to conventional treatments. For preexisting disease, therapeutic agents should be adjusted to the patient's specific condition.

Preliminary Investigation on Micro-Needling with Low-Level LED Therapy and Growth Factors in Hair Loss Related to COVID-19

The incidence of hair loss (HL) and telogen effluvium (TE) has increased due to the spread of the coronavirus disease (COVID-19) induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). New biotechnologies based on micro-needling (MND) with Low-Level LED Therapy (LLLT) and Growth Factors (GFs) used for hair re-growth (HR-G) in Androgenetic Alopecia (AGA) need to be standardized also in HL and TE related to COVID-19. This article aims to describe the preliminary clinical results obtained from an open-label case-series observational study. MND with LLLT and GFs was used in patients affected by HL and TE-related to COVID-19. In total, 10 patients (6 men were identified in stage I–III vertex according to the Norwood–Hamilton scale, and 4 women were identified in stage I–II according to the Ludwig scale) were enrolled and analyzed after screening (exclusion and inclusion criteria evaluation). HR-G assessment was analyzed through photography, physician’s and patient’s global assessment scale, and standardized phototrichograms during a short follow-up: T0—baseline; T1—20 weeks (wks). In the targeted area computerized trichograms showed encouraging results with a hair density increase of 11 ± 2 hairs/cm2 at T1 after 20 wks (20 wks vs. 0 wks) compared with baseline (58 ± 2 hairs/cm2 at T1 versus 47 ± 2 hairs/cm2 at baseline) with a not quite statistically significant difference in HR-G (p = 0.0690). The preliminary effectiveness of MND with LLLT and GFs use has been demonstrated in mild-to-moderate HL and TE related to COVID-19. Further controlled trials are required to confirm these preliminary results.

Hair Loss and Telogen Effluvium Related to COVID-19: The Potential Implication of Adipose-Derived Mesenchymal Stem Cells and Platelet-Rich Plasma as Regenerative Strategies

The diffusion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inducing coronavirus disease 2019 (COVID-19) has increased the incidence of several dermatological disorders, including hair loss (HL). This article aims to review the literature regarding the incidence of HL and telogen effluvium (TE) in COVID-19 patients and critically appraise the available evidence regarding the role of regenerative strategies like Platelet-Rich Plasma (PRP) and Human Follicle Stem Cells (HFSCs). A literature review regarding the correlation of HL and TE in COVID-19 patients analyzing the biomolecular pathway involved and the role of regenerative strategies was performed using PubMed, MEDLINE, Embase, PreMEDLINE, Scopus, and the Cochrane databases. Observational studies revealed an escalated incidence of pattern HL and TE in COVID-19 patients. Psychological stress, systemic inflammation, and oxidative stress are potential culprits. Proinflammatory cytokines and stress hormones negatively affect the normal metabolism of proteoglycans. Reduced anagenic expression of proteoglycans is a potential mediating mechanism that connects HL to COVID-19. Currently, only one study has been published on PRP against HL in COVID-19 patients. Further controlled trials are required to confirm PRP and HFSCs efficacy in COVID-19 patients.