Author: Dr Francisco Flores, Dr Maryam Ameen; and Dr Brittany Tsai, Ross University School of Medicine, USA (2024)
Reviewing dermatologist: Dr Ian Coulson (2024).
Edited by the DermNet content department.
A 15-year-old female presented with discolouration around the neck and abdomen for 3 years. She reported no itching or pain, and no changes in soap or excessive sun exposure.
Physical examination shows:
She was diagnosed with confluent and reticulated papillomatosis. This uncommon skin condition has an unclear cause. Current studies support a bacterial aetiology (a gram-positive actinomycete Dietzia papillomatosis) and the condition responds well to antibiotics.
Differential diagnoses include tinea versicolor (excluded by direct mycology) and acanthosis nigricans.
Confluent and reticulated papillomatosis usually clears with a tetracycline antibiotic. This patient was prescribed minocycline, and the rash resolved.
