Author: Dr Ian Coulson, Consultant Dermatologist and Editor-in-Chief, 2023.
Edited by the DermNet content department
This 18-year-old man has had a rash on his abdomen for 8 months. Mycology has been negative on 3 occasions and it has not responded to oral itraconazole.
There is a slightly scaly net-like (reticulate) eruption on the abdomen.
The features are typical of confluent and reticulated papillomatosis. It is frequently misdiagnosed as pityriasis versicolor, but mycology is negative and oral azoles are not as effective as tetracycline antibiotics.
Recent evidence suggests it is due to infection with a Gram-positive actinomycete called Dietzia papillomatosis.
It usually responds to a course of tetracyclines.
For more information, see the topic page on confluent and reticulated papillomatosis.
