Acetylene has the property of inflaming spontaneously when brought in contact with chlorine.
They certainly seem to have no purpose beyond getting his face in papers and inflaming racial hatred.
Other triggers cab be changes in host defenses e.g. friction during sexual intercourse inflaming the mucous membranes.
The oils used to style hair may be clogging pores and inflaming sensitive skin.
The Turks were threatening western Europe, and Luther was inflaming Germany.
