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Updated: May 27, 2026

Measuring Psoriasis Severity at Home
Published on: March 1, 2024
The impact of salt water soaks on biophysical and molecular parameters in psoriatic epidermis equivalents
T Gambichler1, C Demetriou, S Terras
1Department of Dermatology, Venereology and Allergology, Ruhr University Bochum, Gudrunstrasse 56, Bochum, Germany. t.gambichler@klinikum-bochum.de
Background/Aims:
The exact mechanisms of action of balneophototherapy are incompletely understood. We aimed to investigate the effect of salt water soaks on ultraviolet (UV) transmission and the expression of molecular parameters of psoriasis.
Methods:
We studied UV transmission and the expression of antimicrobial peptides and skin-derived antileukoproteinase (SKALP/elafin) in psoriatic epidermis equivalents which were pretreated with tap water and differently concentrated salt water solutions. Moreover, we performed in vivo phototoxicity tests in healthy subjects.
Results:
Highly concentrated salt water soaks significantly increase UV transmission through psoriatic epidermis equivalents, in particular within the wavelength range of 305- 360 nm. In vivo tests revealed increased photosensitivity following highly concentrated salt water baths. A significant decrease in human β-defensin-2 (hBD-2) and SKALP/elafin is observed after highly concentrated NaCl soaks.
Conclusion:
An increase in UV transmission following highly concentrated salt water soaks likely causes enhanced UV gain within the viable epidermis. Moreover, our data indicate that salt water soaks seem to influence the protein profiles of hBD-2 and SKALP/elafin.
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