Treatment of herpes zoster with idoxuridine ointment, including a multivariate analysis of symptoms and signs.

A double-blind, random selection comparison was made of the therapeutic effects in acute herpes zoster of (A) 40% idoxuridine (IDU) dissolved in dimethyl sulphoxide (DMSO), or one of the following ointments: (B) a basis of polyethylene glycol, (C) a basis with 60% DMSO, (D) a basis with 5% IDU and 60% DMSO, and (E) a basis with 40% IDU and 60% DMSO. Each group comprised 20 patients. The patients were evaluated daily until skin healing and then at 1,3, and 6 months by registering 4 neurological signs, 5 clinical evaluations of skin pathology and 4 photographic evaluations of the skin lesions. A 'profile' of the effect of each treatment was computed by calculating normalized means for each of the 13 variables. A non-random distribution of the clinical and photographic variables indicated a statistically significant, but small therapeutic effect of treatment A on skin healing, whereas no convincing effect on pain or sensitivity disturbances was established. Treatments B-E were without positive effects. The information given by the highly interdependent variables were computed for each variable and for groups of variables after appropriate scoring. It was found that the photographic evaluation contributed evidence independent of the clinical evaluation of skin pathology. A multiple correlation analysis revealed that age was positively correlated to the duration of pain and to delayed healing, that rapid healing was intimately connected to no or short-lived pain, and surprisingly that zoster in the trigeminal area healed faster than in other locations without being correlated to less pain. Treatment A must necessarily be reevaluated taking into account proper controls as well as age and affected dermatomes.