The effect of grenz rays on irritant skin reactions in man.

To investigate the effect of grenz rays on irritant contact reactions, eleven healthy volunteers were studied. They were given 3 Gy of grenz rays, once a week for 3 weeks, to a defined area of the back. Twenty-four hours after the last treatment, serial dilution sodium lauryl sulphate patch tests were applied both on the grenz ray treated area and on the untreated control skin. Biopsy specimens were taken from the irritant reactions both from the grenz ray treated area and from the control area and different cell populations in dermis and epidermis were identified by monoclonal antibodies (Leu 2, 3, 4, 7, Leu M1, B1, OKT6). In the grenz ray treated epidermis there was a pronounced reduction of OKT6-positive cells but the composition of the dermal cellular infiltrate did not differ between control and grenz ray treated skin. The assessment of the patch test reactions did reveal a tendency towards weaker reactions in the grenz ray pre-treated skin but this difference was not statistically significant. It is concluded that grenz rays do not have a marked effect on the elicitation of irritant reactions.