The importance of the coal tar bath in the Ingram treatment of psoriasis. Evaluation by evaporimetry and laser Doppler flowmetry

SUMMARY The contribution of the tar component to the efficacy of the Ingram regimen in the treatment of psoriasis was assessed in 11 patients with symmetrical lesions on the upper extremities. One arm was immersed in an oil emulsion bath and the other in a coal tar bath. Whole body ultraviolet irradiation followed, and dithranol paste was applied to all lesions. Healing was assessed clinically at weekly intervals, and was found to parallel the normalization of transepidermal water loss (TEWL) as determined by evaporimetry, and the dermal blood flow as evaluated by laser Doppler flowmetry. Results obtained with coal tar baths were not significantly different from those obtained with oil emulsion. We conclude that coal tar bath additive has no advantage over oil emulsion in the Ingram regimen.