Psoriasis of the nails treated with grenz rays: a double-blind bilateral trial.

The effect of grenz ray therapy in the treatment of psoriatic nails was assessed in 22 patients by randomly allocating active treatment to the psoriatic nails of one hand while the other one, which received simulated therapy, served as a control. Five Gy of grenz rays were applied on 10 occasions at intervals of 1 week. There was a significantly better response to active treatment compared with the untreated control. However, the therapeutic response was moderate. It is concluded that grenz ray therapy could be useful only when the psoriatic nails are of normal thickness.