Skin blood flow in psoriasis during Goeckerman or beech tar therapy

Skin blood flow (SBF) was measured by the laser Doppler technique in lesional and clinically normal skin of 8 patients with psoriasis vulgaris during Goeckerman or beech tar therapy. The SBF measurements were performed before therapy and 1, 2, and 3-4 weeks after treatment was initiated. The results were compared to a clinical psoriasis index based on the objective assessment of infiltration, erythema, and scaling of the psoriatic plaques. The pre-treatment value of SBF in lesional skin was about 9 times higher than that of clinically normal skin. During therapy SBF of involved skin decreased rapidly approaching that of uninvolved skin after 3-4 weeks. Furthermore, there was a significant linear correlation between the SBF values and the clinical psoriasis index. It is concluded that SBF in psoriatic lesions decreases significantly during Goeckerman or beech tar therapy, and that this variable might be used to obtain a quantitative measure of the disease activity.