I think this research paper by Horiuchi Utako from Gunma University in Japan speaks for itself — the translation of the abstract isn’t perfect, but the meaning is perfectly clear:

1)  A lot of detergent remains in clothing even after excessive rinsing.

2)  A significant amount of those residues can migrate onto other surfaces that come into contact with the clothing, including skin.

The abstract is short and is well worth reading.  The interesting conclusion to Solveeczema users:  “wash the diapers for the babies with hypersensitivity using soaps in stead of synthetic detergents.”

The paper appears to have been published in 1983.