Psoriasis is probably a T-cell-mediated autoimmune disease. Infectious models of autoimmune diseases have been proposed and in psoriasis, it has been suggested that there may be molecular mimicry between streptococcal antigens and epidermal keratins. The immunological profile of stable psoriasis plaques suggests, however, that viral antigens may be important. We investigated, using polymerase chain reaction techniques, whether DNA from either cytomegalovirus (CMV) or human herpes viruses (HHV) 6 and 7 is present in the skin of patients (n = 10) with chronic plaque psoriasis. We also investigated 29 patients for the presence of serum IgG to CMV. We found no evidence of CMV or HHV 7 DNA in psoriasis plaques although DNA for HHV 6 was detected in both involved and uninvolved skin in 1 out of 10 patients. There was no statistically significant increase in prior CMV infection, as assessed by the presence or absence of serum IgG to CMV, in psoriasis, compared to our local population. Although there is circumstantial evidence that viral antigens may be important in the pathogenesis of psoriasis we found no evidence to link infection with CMV or HHV 6 and 7 with subsequent development of chronic plaque psoriasis.

Adult↗

PubMedDate not supplied

Prevalence of occult human papillomavirus infection, determined by cytology and DNA hybridization, in heterosexual men attending a genitourinary medicine clinic.

One hundred and five heterosexual men without evidence of clinical anogenital warts and attending a genitourinary medicine clinic were studied. Three separate specimens for cytology were taken from (i) the distal urethra including the perimeatal area, (ii) the penile shaft and glans penis including the sub-preputial area, and (iii) from the anorectal area using a proctoscope. Pooled specimens of exfoliated cells from these sites were also taken for the detection of human papillomavirus (HPV) by DNA hybridization. Twenty-eight (27%) of the men had cytological evidence suggestive of HPV infection. HPV genome was detected in 21 (20%) of the men by DNA hybridization and 95% of them were carrying HPV 16 genotype either alone or in combination with other genotypes. A total of 42 (40%) of patients had evidence of occult HPV infection using cytology and/or DNA hybridization techniques collectively. None of the epidemiological risk factors were significantly associated with occult HPV infection in this study. The significance of this high incidence of sexually transmissible HPV genomes, mostly HPV16 in the anogenital area of heterosexual men attending genitourinary medicine clinics requires further study.

Adolescent↗