Shingles May Run in the Family

By Todd Neale
HOUSTON, 20 may 2008 -- Family history appears to be a risk factor for herpes zoster, suggesting a genetic basis for susceptibility to shingles, a case-control study showed.
A significantly higher percentage of 504 patients with herpes zoster reported having a blood relative with the disease compared with 523 controls (39.3% versus 10.5%, P<0.001), Lindsey Hicks, B.S., of the University of Texas Medical School, and colleagues reported in the May issue of the Archives of Dermatology.
Those who had the disease were four-and-a-half times more likely than controls to report one affected relative (OR 4.50, 95% CI 3.15 to 6.41), with the risk increasing by almost 14 times in those with more than one relative with shingles (OR 13.77, 95% CI 5.85 to 32.39) (P<0.001 for both).
"In light of genetic advances in infectious disease susceptibility," the researchers said, "our study indicates that further studies into this area may be necessary in order to recognize and vaccinate susceptible individuals."
Known risk factors for herpes zoster include older age, illness, use of immunosuppressive therapies, and impaired immunity from diseases such as HIV or AIDS and cancer, the researchers said.
Other possible factors include sex, ethnicity, seasonality, psychological stress, physical trauma, and exposure to heavy metals.
But a possible genetic susceptibility to the disease has only recently been proposed, and family history as a risk factor has not been adequately studied, they said.
So the researchers interviewed patients who had been examined at the Center for Clinical Studies in Houston from Jan. 1, 1992 through Aug. 15, 2005 and diagnosed with herpes zoster (504) or another skin condition (523), such as psoriasis or atopic dermatitis.
Participants were not asked about use of the herpes zoster vaccine (Zostavax) because it was not approved by the FDA until 2006.
Participants with shingles were 4.35-fold more likely than controls to have a parent, sibling, or child with the disease (OR 4.35, 95% CI 3.11 to 6.09) and 4.27-fold more likely to have a non-first-degree relative with the disease (OR 4.27, 95% CI 2.44 to 7.49) (P<0.001 for both).
In a logistic regression model, sex, age, and race were not significant predictors of herpes zoster.
In regard to race, however, "our study involved predominantly white patients, and, therefore, no assumptions about racial differences in [herpes zoster] susceptibility can be made based on our data," the researchers said.
The authors said that the study may have been subjected to recall bias -- because of the self-reported family history -- and detection bias -- because controls could not adequately be evaluated for a history of herpes zoster.
However, they said, "the strength of the association found in this study between [herpes zoster] and family history suggests that bias does not completely explain our results."
In addition, they said "our study documented a dose-dependent effect between having a single blood relative and having multiple blood relatives with a history of herpes zoster."
They concluded that patients with a family history of the disease "represent a population that may be at increased risk of developing [herpes zoster] and, therefore, have a greater need for vaccination. Therefore, targeting these at-risk individuals based on their family history may decrease both their chance of future [herpes zoster] infection and healthcare expenditures toward [herpes zoster] morbidity."
Future studies, they said, are needed to confirm that this association is explained by genetic susceptibility.
The authors made no disclosures.
Primary source: Archives of DermatologySource reference:Hicks L, et al "Family history as a risk factor for herpes zoster" Arch Dermatol 2008; 144: 603-608.