- Presents around adolescence
- More common in blacks, with a female predominance
- Presents with small papules on the chest, back and upper arms
- The papules enlarge and eventually become confuent and reticulated.
- The epidermis shows papillomatosis with hyperparakeratosis and often acanthosis.
- Downgrowths of the epidermis between the rete ridges
- Mild increase or sometimes decrease in basal layer pigmentation
- Dermal vascular dilatation with a mild perivascular lymphohistiocytic infiltrate
- There is sometimes fragmentation of upper dermal elastic fibers and mild papillary dermal edema.