Headache as a COVID‐19 onset symptom and post‐COVID‐19 symptom in hospitalized COVID‐19 survivors infected with the Wuhan, Alpha, or Delta SARS‐CoV‐2 variants

OBJECTIVE: This study looked at differences in the presence of headache as an onset symptom of coronavirus disease 2019 (COVID‐19) and as a post‐COVID‐19 symptom in individuals previously hospitalized owing to infection with the Wuhan, Alpha, or Delta variants of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). BACKGROUND: Headache can be present in up to 50% of individuals during the acute phase of SARS‐CoV‐2 infection and in 10% of subjects during the post‐COVID‐19 phase. There are no data on differences in the occurrence of headache in the acute‐ and post‐COVID‐19 phase according to the SARS‐CoV‐2 variants. METHODS: A cross‐sectional cohort study was conducted. Unvaccinated subjects previously hospitalized for COVID‐19 caused by the Wuhan (n = 201), Alpha (n = 211), or Delta (n = 202) SARS‐CoV‐2 variants were scheduled for a telephone interview 6 months after hospital discharge. Hospitalization data were collected from hospital medical records. RESULTS: The presence of headache as a COVID‐19 onset symptom at hospitalization was higher in subjects with the Delta variant (66/202, 32.7%) than in those infected with the Wuhan (42/201, 20.9%; odds ratio [OR] 1.83, 95% confidence interval [CI] 1.17–2.88) or Alpha (25/211, 11.8%; OR 3.61, 95% CI, 2.16–6.01) variants. The prevalence of post‐COVID‐19 headache 6 months after hospital discharge was higher in individuals infected with the Delta variant (26/202, 12.9%) than in those infected with the Wuhan (11/201, 5.5%; OR 2.52, 95% CI 1.22–5.31) or Alpha (eight of 211, 3.8%; OR 3.74, 95% CI 1.65–8.49) variants. The presence of headache as a COVID‐19 onset symptom was associated with post‐COVID‐19 headache in subjects infected with the Wuhan (OR 7.75, 95% CI 2.15–27.93) and Delta variants (OR 2.78, 95% CI 1.20–6.42) but not with the Alpha variant (OR 2.60, 95% CI 0.49–13.69). CONCLUSION: Headache was a common symptom in both the acute‐ and post‐COVID‐19 phase in subjects infected with the Wuhan, Alpha, and Delta variants but mostly in those infected with the Delta variant.