Abstract: JEADV COVID-19 SPECIAL FORUM 5-alpha-reductase inhibitors are associated with reduced frequency of COVID-19 symptoms in males with androgenetic alopecia Dear Editor We have previously reported that men with androgenetic alopecia (AGA) are more likely to present with severe COVID-19 symptoms, potentially implicating androgen sensitivity as a risk factor for COVID-19.1–3 As such, we hypothesized that 5-alphareductase inhibitors (5ARi) may reduce the severity of COVID- 19 disease. To test this hypothesis, we conducted a retrospective cohort analysis on male subjects with laboratory confirmed SARS-CoV-2 infection. The subjects presented at one of five outpatient clinics (Corpometria Institute Brasilia, Brazil) from 15 June to 28 July 2020. At the time of visit, 29 clinical symptoms associated with SARS-CoV-2 infection were documented. For analysis, male subjects with AGA were selected. The frequency of clinical symptoms in males with AGA using 5ARis was compared to those not using 5ARis. Among the men presenting at the clinic, 300 were positive for SARS-CoV-2. Of these, 65 had AGA but were not using 5ARis, and 48 had AGA and were taking a 5ARi for at least six months prior to the study. The only 5ARi used in this cohort was dutasteride (0.5 mg) for the treatment of AGA. Propensity score Table 1 Baseline characteristics of androgenetic alopecia men with COVID-19 by use and non-use of 5-alpha-reductase inhibitors All SARS-CoV-2 positive 5ARi (n = 48) Group-determing data, No (%) Baseline data, No (%) JEADV 2021, 35, e243–e307 No 5ARi (n = 48) Androgenetic alopecia 48 (100) 48 (100) Dutasteride use 48 (100) 0 (0) Average Age, No.(SD) 45.6 (12) 45.7 (9) BMI >30 kg/m2 9 (19) 8 (17) Hypertension 12 (25) 11 (23) Myocardial infarction 2 (4) 2 (4) Stroke 0 (0) 0 (0) Heart Failure 0 (0) 0 (0) Lipid Disorder 24 (50) 17 (35) Diabeties 9 (19) 5 (10) Prediabeties 3 (6) 1 (2) Obesity 9 (19) 8 (17) Asthma 2 (4) 5 (10) COPD 0 (0) 0 (0) Cancer (current) 0 (0) 0 (0) Cancer (previous) 0 (0) 1 (2) Benign prostatic hyperplasia 5 (10) 2 (4) Prostate Cancer 0 (0) 0 (0) Chronic renal disease 0 (0) 0 (0) Liver fibrosis/cirrhosis 0 (0) 0 (0) Clinical depression 5 (10) 0 (0) Anxiety 7 (15) 5 (10) ADHD 6 (13) 4 (8) Insomnia 5 (10) 2 (4) Hypogonadism 3 (6) 4 (8) Hypothyroidism 2 (4) 1 (2) Autoimmune 0 (0) 0 (0) Other Diseases 0 (0) 0 (0) © 2020 European Academy of Dermatology and Venereology Letters to the Editor e244 Table 1 Continued All SARS-CoV-2 positive 5ARi (n = 48) No 5ARi (n = 48) Medications used, No. (%) Anti-hypertensives Lipid-reducing agents Anti-coagulants Anti-diabetics Hypothyroidism Hypogonadism Central-acting drugs Androgenetic alopecia (others) Beta-blocker 4 (8) 3 (6) ECAi 5 (10) 4 (8) Angiotensin II receptor blockers 9 (19) 9 (19) Loop diuretics 1 (2) 0 (0) Thiazide diuretics 4 (8) 4 (8) Calcium channel blockers 6 (13) 4 (8) K-sparing diuretics 0 (0) 1 (2) Statins 23 (48) 14 (29) Others 2 (4) 2 (4) Aspirin 2 (4) 2 (4) Clopidogrel 0 (0) 0 (0) Xa factor inhibitors 3 (6) 0 (0) Metformin 11 (23) 10 (21) GLP1R analogue 3 (6) 2 (4) SGLT2 inhibitors 5 (10) 2 (4) DPP4 inhibitors 4 (8) 3 (6) Sylfonylureas 1 (2) 0 (0) Glitazone 0 (0) 1 (2) Acarbose 0 (0) 0 (0) Insulin 0 (0) 1 (2) Orlistat 2 (4) 5 (10) Levothyroxine 2 (4) 1 (2) Liothyronine 0 (0) 0 (0) Testosterone 1 (2) 4 (8) Aromatase..