studies were questionnaire-based, used self-reports of symptoms or physician-diagnosed conditions, and used veterans without PTSD as the comparison population. The assessment of PTSD, which was similar in the two studies, was based on a screening questionnaire, the PTSD Checklist, with standard cutoffs. In a nested case-control study drawn from the population-based study of Iowa veterans of the Gulf War, Barrett et al. (2002a) found the prevalence of current dermatologic conditions and dermatologic symptoms to be higher in 53 veterans with current PTSD (over 90%) than in 3629 veterans without PTSD (about 25%). The study was conducted by telephone interview 5 years after the Gulf War. This nested case-control component of the larger cohort study conducted by the Iowa Persian Gulf Study Group (1997) is limited by lack of specification in the analysis of which particular dermatologic symptoms or conditions might be more prevalent.
The Veterans Health Study of 2425 consecutive male ambulatory-care patients seen at four VA medical centers screened veterans for PTSD with the PTSD Checklist. Patients who screened positive (n = 456) reported higher rates of dermatitis than those without PTSD (OR 2.37, 95% CI 1.88-3.0) (Spiro et al. 2006). The study is limited, however, by its lack of a control population, lack of reporting of veterans’ previous deployment status, and absence of identification as to whether PTSD was related to a deployment-related trauma.
Another case-control study was nested within the VES. It sought to determine whether combat-related PTSD was associated with development of a wide variety of medical disorders (Boscarino 1997). Case subjects were PTSD-positive Vietnam veterans with high combat exposure, and controls were PTSD-negative veterans with low combat exposure. Lifetime PTSD status was determined with in-person interviews that used the DIS, and combat exposure was determined with the Laufer Combat Exposure Scale. Medical disorders were ascertained during the in-person interviews by asking veterans to respond affirmatively or negatively to a list of specific medical conditions as to whether they had been diagnosed by a physician and whether the condition occurred before or after discharge. The conditions were later collapsed into general medical categories to minimize the likelihood of reporting bias. The study found no excess of dermatologic diseases occurring after discharge in veterans with PTSD vs those without PTSD (OR 1.09, 95% CI 0.59-1.04) after adjustment for general technical test results, race, region of birth, type of enlistment, Vietnam volunteer status, marital status, age, hypochondriasis, physical limitations in the military record, and psychiatric limitations in the military record. Key advantages of the study are its focus on combat-related PTSD, its ascertainment of PTSD with the DIS, a well-validated structured psychiatric interview based on DSM criteria, and use of a combat exposure scale. Another study strength is its adjustment for a host of preservice and postservice behavioral risk factors and physical or psychiatric limitations reported in the military record at the time of service. The major study limitation is the lack of specificity regarding particular dermatologic diseases.
In a later case-control analysis of the VES, Boscarino (2004) tested the hypothesis that combat-related PTSD increases the risk of autoimmune disease after discharge. The prevalence of 20 autoimmune diseases was examined in 124 Vietnam-theater veterans with comorbid PTSD and 54 veterans with current but noncomorbid PTSD (less severe PTSD according to the author). Psoriasis was the one of nine autoimmune diseases with dermatologic manifestations. After multivariate analysis—adjusted for age, education, race, intelligence, geographic region, Army volunteer status, number of times married, smoking, and history of psychiatric disorder—psoriasis was found to be nearly 5 times more prevalent in veterans with comorbid PTSD than in veterans without PTSD (OR 4.7, 95% CI 1.9-11.7).