The anatomy of the rete ridge pattern of the face differs from that of non-facial skin, and is usually flatter. Accordingly, the pigment network is usually absent in these locations and is replaced by a pseudonetwork pattern. The "holes" in the pigmented epidermis correspond histologically to adnexal openings, such as sebaceous glands, hair follicles or sweat glands.
A pseudonetwork sketch:
Clinical and dermoscopic images of pseudonetwork:
Histologically, adnexal openings are responsible for the "holes" in the pigment reticulation: