Effect of atopic conditions on development and recurrences of infectious keratitis

Background: Atopic conditions are known to be associated with viral and bacterial infections. The purpose of this study was to determine the relationship between the effects of atopic conditions on the severity and recurrence of ocular infections including herpes simplex virus (HSV). Methods: This study was performed on 474 consecutive patients with infectious keratitis caused by bacteria, fungus, acanthamoeba, HSV, or varicella-zoster virus. The relationships between the atopic condition and specific infectious pathogens and HSV were determined using real-time PCR. Results: Our findings showed that atopic dermatitis (AD) was significantly associated with the incidence of HSV keratitis (odds ratio (OR), 10.2; P = 0.000). Other associations with AD were observed only with bacteria in an adverse manner. HSV proliferation in the lesions of patients with HSV keratitis whose AD was associated with non-infectious atopic blepharitis were significantly greater by 145-folds (P = 0.000). The presence of asthma or allergic rhinitis also increased the HSV DNA copy numbers.A recurrence of HSV keratitis was observed in 70 patients (43.2 %), and mean time to recurrence was 1647 days. Cox proportional hazard model indicated that the epithelial type of HSV recurrence but not the stromal type was associated with atopic conditions especially with AD. The factors significantly associated with a recurrence was AD associated with non-infectious atopic blepharitis (HR: 6.11, P = 0.000) and asthma (HR: 3.03, P = 0.025). Conclusions: Atopic conditions, especially AD with atopic blepharitis, are significantly associated with the development, increased proliferation, and shorter time to a recurrence on HSV keratitis.