Periorificial dermatitis (PD) is an inflammatory disorder of the facial skin that mainly occurs around the mouth and manifests as erythema, papules, pustules, scales and other lesions. Special attention is needed in the clinical diagnosis of PD to distinguish it from acne, seborrheic dermatitis (SD), granulomatous rosacea (GR), sarcoidosis and childhood granulomatous periorificial dermatitis (CGPD). We used reflectance confocal microscopy (RCM) images of a patient with PD to assist in the diagnosis of PD. RCM of PD showed slight oedema of the spinous layer. Numerous dendritic cells, scattered hair follicular keratotic plugging and hair follicle dilatation were observed. The dilation and congestion of superficial dermis blood vessels, an increasing vascular density and accelerated blood flow, and a greater abundance of infiltrated inflammatory cells were also detected.