HMGB1 and Headache: In COVID-19 headache patients who are unresponsive to paracetamol, HMGB1 level was significantly elevated (989.3 ± 263.5 vs 514.7 ± 248.9, p < 0.001) whereas IL-10 level (16.1 ± 11.9 vs 19.4 ± 5.6 p = 0.017) was decreased.