Is confluent and reticulated papillomatosis without papillomatosis early or late stage of confluent and reticulated papillomatosis?

The histologic findings of confluent and reticulated papillomatosis include papillomatosis, hyperkeratosis, and minimal or no acanthosis. We present a patient with the clinical findings of confluent and reticulated papillomatosis who responded dramatically to azithromycin, but histologic examination did not reveal papillomatosis. We observed invagination of basket-weave hyperkeratosis through the epidermis. We considered this finding may give a clue for the diagnosis of confluent and reticulated papillomatosis.