Abstract: | Background: Perioral dermatitis (PD) is a common dermatological disease whose aetiology and pathogenesis remain speculative. We investigated skin barrier function and various markers of the atopic diathesis to elucidate their impact on the development of perioral dermatitis. Patients and methods: Forty patients (24 to 69 years of age) with PD were evaluated. Transepidermal water loss was measured in three regions of the face (lateral chin, perinasal cheek and side of the nose) and the patients were assessed for clinical criteria for atopy. Prick tests were performed, and specific IgE against a mixture of aeroallergens (CAP SX1) was measured. The control group consisted of 62 individuals (20 to 68 years of age) without a history of PD or active disease. Results: Transepidermal water loss was significantly increased (P < 0.001) on all regions of the face in the patient over the control group. Significantly (P < 0.001) higher values were also found for the patient group regarding history (52.5 % vs. 17.7 %) and clinical signs of atopic diathesis (≥ 4 features: 72.5 % vs. 0 %), prick test reactivity (≥ 2 reactive prick tests: 60 % vs. 12.9 %), and specific IgE against aeroallergens (CAP SX1 classes ≥ 2: 60.0 % vs. 17.7 %). Conclusions: Our findings emphasize the relevance of impaired skin barrier function as a pathogenic factor in the causation of perioral dermatitis. The susceptibility of atopic skin to irritants increases as soon as the skin becomes eczematous. Therefore, we propose that atopic diathesis serves as an intensifier, supporting development and continued presence of perioral dermatitis after nonspecific irritant mechanisms have induced impaired skin barrier function. |