Rates of and factors associated with atopy and allergies in posttraumatic stress disorder as compared to controls

Several studies suggest a relationship between atopy and psychiatric disorders, but few have investigated the association between atopic conditions and posttraumatic stress disorder (PTSD). We sought to compare the rates of atopy and allergies in a South African case-control study of 220 patients with PTSD (mean age 41.7 years, SD = 11.7) and 196 trauma exposed controls (TEC, mean age 45.4 years, SD = 14.7) conducted in Cape Town, South Africa from May 2014 to June 2017.

Self-reported atopic conditions and allergies were regressed on PTSD, as determined with the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5), in multivariate logistic regression models, controlling for age, gender, body mass index, physical activity, lifetime and childhood trauma, and time since index trauma.

Rates of lifetime atopy (p = 0.03), current asthma (p = 0.04), lifetime allergic rhinitis (p = 0.002), and current allergic rhinitis (p = 0.004) were significantly higher in patients than TEC on bivariate analysis. On multivariate analysis, rates of current atopy (Cohen's d = 0.26, p = 0.04) and current allergic rhinitis (Cohen's d = 0.34, p = 0.012) were significantly higher in patients with PTSD than in TEC. Current eczema (p = 0.24), current asthma (p = 0.26), and allergies (p = 0.59) were not associated with PTSD.

Rates of atopy are higher in participants with PTSD than TEC, and this effect is related to higher rates of allergic rhinitis. Further studies are needed to elucidate the pathways linking allergic rhinitis and PTSD.