Finally, older male World War II and Korean War veterans participating in the Normative Aging Study who screened positive for lifetime PTSD (n > 580) using the Mississippi Scale for Combat-Related PTSD were more likely to have new onset of dermatologic disorders (hazard rate 1.18, 95% CI 1.05-1.34) according to physical examinations conducted periodically beginning in the 1960s, than veterans without PTSD (Schnurr et al. 2000). Dermatologic diseases (ICD 690-698) included eczema, dermatitis, and psoriasis. Dermatologic disorders increased by 18% for every 10-point increment in PTSD symptom scores.
The committee placed the greatest weight on studies that included medical evaluation and identification of specific dermatologic diagnoses. All four primary studies showed a higher prevalence of some skin diseases or conditions in deployed than in nondeployed veterans. A nationally representative study of Gulf War veterans found a relationship between deployment and atopic dermatitis and verruca vulgaris (warts), but not other skin conditions (Eisen et al. 2005). A UK study of Gulf War veterans found a relationship between deployment and seborrheic dermatitis (Higgins et al. 2002). Each of those dermatologic associations is supported by a single primary study, although Ishoy et al. (1999) also found an increased prevalence of eczema in deployed Gulf War veterans. The VES showed no increase in selected skin conditions not related to exposure to Agent Orange in Vietnam-theater veterans (CDC 1988b).
Secondary studies are largely consistent with the primary studies but lack specificity regarding dermatologic outcomes. Many report higher prevalences of self-reported symptoms or physician-diagnosed dermatologic conditions in deployed than in nondeployed veterans. Some secondary studies are somewhat more specific in reporting a greater prevalence of eczema or psoriasis (Kang et al. 2000b) or eczema alone (Wolfe et al. 1998).
Dermatologic conditions are highly common in veterans regardless of deployment status. Verruca vulgaris is known to be caused by a virus, and seborrheic dermatitis is thought to be caused by a combination of sebaceous gland secretions, microfloral metabolism, and individual susceptibility (Ro and Dawson 2005). Therefore, the higher prevalence of those two conditions in deployed than in nondeployed veterans are more likely related to environmental conditions in the Gulf War or may simply be due to chance.
The other two conditions—atopic dermatitis and psoriasis—have more plausible relationships with deployment stressors. Both are mediated by the immune system, which has strong interrelationships with the stress response. In the case of psoriasis, the epidemiologic evidence comes directly from one of the primary studies implicating combat-related PTSD of high severity in the onset of psoriasis (Boscarino 2004). Case subjects not only had a higher prevalence of other autoimmune diseases but displayed five biologic markers of autoimmune and other inflammatory diseases. Other controlled studies of psoriasis patients found that introduction of psychologic stressors is associated with biologic alterations in the stress response (Buske-Kirschbaum et al. 2007).
In the case of atopic dermatitis, a large body of research over the last decade suggests immune dysregulation in its pathophysiology and psychologic stress as a key trigger in its maintenance or exacerbation (Leung and Soter 2001). Controlled clinical trials found that patients with atopic dermatitis show attenuated activity of the HPA axis and overreactivity of the sympathetic adrenomedullary system in response to psychologic stressors (Buske-Kirschbaum et al. 2002). Those findings are consistent with the findings from veteran studies. Skin conditions (as a broad category) were directly linked to deployment stressors via a combat exposure index