Confluent and reticulated papillomatosis: diagnostic and treatment challenges

Confluent and reticulated papillomatosis (CRP) of Gougerot and Carteaud was first typified in 1927. With the help of electron microscopy, it has been elucidated that CRP arises due to aberrant keratinization. However, till date, there is no clear consensus on the etiologic trigger for CRP. Prevailing postulates include a bacterial trigger by Dietzia papillomatosis (type strain N 1280(T)), an exaggerated cutaneous response to Malassezia furfur, an endocrine basis stemming from insulin resistance, ultraviolet light-induced epidermal change, amyloid deposition, and a loss-of-function mutation in keratin 16. CRP typically presents as asymptomatic hyperpigmented papules and plaques with peripheral reticulation over the nape, axillae, upper chest, and upper back, occasionally with extension superior to the forehead and inferior to the pubic region. Dermoscopy may be used in the evaluation of CRP, but its diagnosis is made on clinical grounds given its nonspecific histopathological findings. Although successful treatment with topical keratolytics, retinoids, or antifungals has been reported, antibiotics, such as minocycline, at anti-inflammatory doses have emerged as a preferred therapeutic option. In this article, we review the diagnostic considerations in CRP and its therapeutic options.