CMV
CMV is a prevalent viral pathogen.21 Most people with acute CMV experience an inapparent infection. The virus usually is spread through close personal contact, including sexual transmission. There has been debate over the link of alopecia areata with CMV. In 1995, Skinner et al22 described using polymerase chain reaction (PCR) techniques to find evidence of CMV DNA in paraffin block sections of lesions of alopecia areata. Of 21 patient biopsy specimens, 10 had alopecia areata and 11 had other hair loss conditions. Of the 10 alopecia areata samples, 9 were positive for CMV; no other hair loss samples were positive for CMV.22 Skinner et al23 theorized that CMV may achieve latency in the hair root. Reactivation of CMV was thought to be one of the pathogenic mechanisms in alopecia areata; the authors argued that a lymphocytic surveillance of not-quite-latent CMV would explain much of the behavior of alopecia areata, which has a tendency for intermittent relapses and remissions.23
The association between alopecia areata and CMV was refuted by Garcia-Hernandez et al,24 who used 3 different PCR assays to detect CMV DNA in skin punch biopsy specimens of 3 patient groups: 40 patients with alopecia areata, 3 patients with HIV and alopecia areata, and 12 patients with other types of alopecia. PCR assays are known to be the most sensitive assay for CMV detection; this study used different PCR assays to achieve maximum sensitivity for CMV. No CMV DNA amplification was found in any of the specimens.24
Offidani et al25 further contradicted this association. The purpose of their study was to clarify the role of CMV infection and to demonstrate the absence of replication of other autoimmune disease–related herpesviruses (eg, Epstein-Barr virus) in the pathogenesis of alopecia areata. After extraction of mRNA from tissue samples of 4 patients with active patchy alopecia areata, reverse transcriptase PCR was carried out using primers specific for some viral members of the β Herpesviridae subfamily of the Herpesviridae family (eg, CMV, Epstein-Barr virus, herpes simplex virus). The authors could not detect any replication of the CMV or other β Herpesviridae in the samples collected, which supports the hypothesis that CMV is not the triggering factor in alopecia areata, neither as a reactivator of the immune response nor as a trigger of the autoimmunity.25
Conclusion
Although many etiologies exist for hair loss, STDs should not be overlooked in a sexually active patient presenting with an otherwise unexplainable cause of this condition. A full workup, including clinical history, physical examination, and laboratory tests, should include STDs in the differential diagnosis (Table).