Funding for this research was provided by:
Received: 11 January 2022
Accepted: 12 May 2022
First Online: 23 May 2022
: The study was approved by the local ethics committee of the Friedrich-Alexander-Universität Erlangen-Nürnberg (Vote No. 209_21 Bc) and was performed in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments. All patients gave informed written consent for the performed medical procedures during their consultation. As this study was conducted retrospectively from medical charts, only data previously obtained for clinical purposes were extracted and anonymously analysed, and all medical information is reported in a de-identified form, consent to participate and to publish is not applicable.
: Not applicable.
: All authors have received payments for unbiased medical expert testimony in the evaluation of occupational diseases (including respiratory diseases in hairdressers) ordered by courts or the (in Germany mandatory) statutory accident insurance carriers for work (= public body).