Confluent and reticulated papillomatosis (Gougerot-Carteaud syndrome) in two brothers.

Confluent and reticulated papillomatosis (CRP) is a rare dermatosis of unknown origin characterized by hyperpigmented, confluent papules (1). CRP was first described in 1927 by Gougerot and Carteaud as " pap-illomatose pigmentée innominée " (2). It has been described as a relatively rare dermatosis manifesting as persistent papules that are confluent in the center and reticulated at the periphery (3). Lesions usually appear as small erythematous papules that evolve into hyperkeratotic verrucous plaques. Although the disease presents with characteristic cutaneous signs, it is difficult for physicians to diagnose (4,5). The differential diagnosis of CRP includes tinea versicolor, Darier's disease, acanthosis nigricans, prurigo pig-mentosa, Dowling-Degos disease, and reticulate hy-perpigmented eruptions (6). Sometimes, the accompanying positive family history, considered together with characteristic clinical findings, may point to the correct diagnosis (6). We report on the cases of two brothers with CRP that suggest genetic predisposition in family members and a possibility of bacterial etiology. Two brothers, aged 19 and 16, were admitted to our outpatient service with maculopapular eruptions on the chests. The lesions had started two years ago in the older brother and two months ago in the younger brother. Both of them had been treated before for seborrheic dermatitis, but neither of them had any improvement with these treatment regimens. They did not have any other family members affected with similar lesions. In dermatological examination, both brothers had milimetric, light to dark brown colored, maculopapular lesions which were coalescing at the center and reticulating at the periphery, creating an inverted triangular shape on their chest skin (Figures 1,2). In laboratory examination, the results of a complete blood count and routine biochemistry were within normal limits. No fungal elements were seen in native microscopic examination. Skin punch biopsies were performed, and pre-diagnoses of confluent and reticulated papilloma-tosis and acanthosis nigricans was established. In histopathological examinations, slight acanthosis, minimal papillomatosis, and superficial perivascular Figure 1. Older brother before treatment. Figure 2. Younger brother before treatment.