The usefulness of reflectance spectrophotometric measurements during psoralens and ultraviolet A therapy for psoriasis.
Reflectance spectrophotometry was used to obtain indices of the hemoglobin and melanin content of psoriatic lesions and adjacent clinically normal skin in thirteen patients undergoing photochemotherapy. The pretreatment lesional hemoglobin index was 2.8 times greater than that of adjacent uninvolved skin. With therapy, this index decreased rapidly initially, and during the second or third week approached that of the uninvolved skin. The ratio of lesional and uninvolved skin hemoglobin indices decreased to approximately 1.3, and continuation of PUVA treatment failed to reduce it further. Termination of treatment at this stage, which occurs before clinical resolution, resulted in subsequent clearance of psoriasis. The decrease in the lesional hemoglobin index and the clearance time appeared to be dose-dependent, and, indeed, a more aggressive regimen resulted in approximately 50% reduction in both the number of treatments and the cumulative dose required to achieve a stable hemoglobin index ratio and subsequent clinical clearance.
D000328:Adult; D004890:Erythema / Q000378:metabolism; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008297:Male; D008543:Melanins / Q000032:analysis; D011701:PUVA Therapy; D010778:Photochemotherapy; D011565:Psoriasis / Q000188:drug therapy*; D012867:Skin / Q000032:analysis; D013053:Spectrophotometry; D013997:Time Factors
D006454:Hemoglobins; D008543:Melanins