Confluent and Reticulated Papillomatosis without Papillomatosis

Lee, See Hyun; Ahn, Ji Young; Park, Mi Youn

Abstract

Confluent and reticulated papillomatosis (CRP) was first described as a relatively rare dermatosis. CRP is characterized by slightly hyperkeratotic pigmented papules that are confluent in the center and reticulated at the periphery, located on the neck, abdomen, intermammary, and interscapular regions. Histopathologically, lesions typically reveal orthohyperkeratosis, papillomatosis, and focal acanthosis. A 20-year-old man presented with a 2-year history of slightly pruritic lesions on the chest, abdomen, back, and upper extremities. The lesions were brownish papules and plaques in a reticulated and coalescing pattern. Histologically, a basket-weave pattern of orthohyperkeratosis and mild acanthosis were seen. However, there was no significant papillomatosis, even in multiple sections. Periodic acid Schiff stain was negative for fungi. The patient was treated with doxycycline, 200 mg daily, for 4 weeks. The lesions completely resolved and did not recur during 12 months of follow-up. We report a rare case of CRP without papillomatosis.