A 14-year-old moderately obese Hispanic female is concerned about dark areas on her trunk. These are asymptomatic but unsightly. Duration is approximately 6 months. Laboratory work-up, including thyroid-stimulating hormone and fasting glucose, revealed no abnormality. Topical ketoconazole proved ineffectual. On examination, well-demarcated hyperpigmented patches, many with slightly raised papules, are noted on her chest and back.
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Confluent and reticulated papillomatosis is an uncommon disorder of the skin that affects mostly young adults. The exact cause is unknown, although some cases have been associated with Malassezia furfur.1 The rash typically presents on the trunk as papules that form a reticular pattern. The dermatitis may clinically resemble acanthosis nigricans, although the latter characteristically arises in flexural areas, especially the posterior neck and fossae.2
Diagnosis is often delayed because presentation can mimic a yeast infection. Indeed, skin biopsy may reveal, besides hyperkeratosis, pityrosporum.3
The most effective treatment is oral antibiotics.4 Minocycline, at twice per day dosing for a minimum of a month, is usually curative, although early discontinuation of therapy can lead to recurrence. Topical therapies are usually not effective.
Rebecca Geiger, PA-C, is a physician assistant on staff at the DermDox Dermatology Center in Hazleton, Pennsylvania. Stephen Schleicher, MD, is an associate professor of medicine at the Commonwealth Medical College in Scranton, Pennsylvania, and an adjunct assistant professor of dermatology at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia.
- Wei GC, Chong WS. Confluent and reticulate papillomatosis of Gougerot and Carteuad: A review of 7 patients in National Skin Centre, Singapore. J Am Acad Dermatol. 2012;16(Suppl 1):AB47.
- Park YJ, Kang HY, Lee ES, Kim YC. Differentiating confluent and reticulated papillomatosis from acanthosis nigricans. J Cutan Pathol. 2015 Aug 12 doi: 10.1111/cup.12581.
- Schwartz RA. Confluent and reticulated papillomatosis. Available at: https://emedicine.medscape.com/article/1106748-overview. Updated May 4, 2017. Accessed March 2, 2018.
- Scheinfeld N. Confluent and reticulated papillomatosis: a review of the literature. Am J Clin Dermatol. 2006;7:305-313.