Conflicts of interest: S.G.K. is an advisory board member/consultant for AbbVie, Celldex Therapeutics, Galderma, Incyte, Pfizer, Regeneron Pharmaceuticals and Kiniksa Pharmaceuticals, and has served as an investigator for Galderma, Kiniksa Pharmaceuticals, Pfizer Inc. and Sanofi; the other authors declare they have no conflicts of interest.Data availability: further information regarding the data and its purchase are available through the Healthcare Cost and Utilization Project (Agency for Healthcare Research and Quality), available at https://www.hcup-us.ahrq.gov/nisoverview. jsp (last accessed 27 May 2022).Ethics statement: this study utilized deidentified data and was deemed exempt by the Johns Hopkins Institutional Review Board.