We described here a case of a 43-year-old male who developed confluent and reticulated papillomatosis (CRP). The patient was found to be slightly obese and had no family history of such eruption. Numerous small red-brown erythemas were scattered over a wide area of the back and, in many areas, the erythemas coalesced and formed a reticular pattern. The eruptions appeared 10 days prior to the initial visit to our outpatient clinic. The Parker-KOH preparation of scraped scales revealed numerous round and budding non-clustering cells and no mycelial elements. Histological examination showed subtle papillomatosis and sparse perivascular lymphohistiocytic infiltrations. Periodic acid schiff stain showed a few spores in the stratum corneum. Topical application of 2 % ketoconazole cream produced complete resolution of the eruption in 7 days. The course and histological findings of our patient suggest the eruptions were developing CRP lesions. Application of topical antifungal agents appears to be a beneficial initial treatment for early CRP lesions.
Two Trichophyton mentagrophytes isolates from skin lesions on a girl and her rabbit, which were identified as Arthroderma benhamiae by mating tests, were studied by mtDNA (mitochondrial DNA) analysis and sequencing of ITS (internal transcribed spacer) regions of nuclear ribosomal RNA genes. The mtDNA-RFLP (restriction fragment length polymorphism) patterns showed the two isolates to be T. verrucosum rather than A. benhamiae. The ITS sequence showed the isolates to be closer to A. benhamiae Americana-European race than to T. verrucosum and closer to T, verrucosum than to their mating partner A. benhamiae African race. These results suggest that there are three genetic types of A. benhamiae - an Americano-European type, an African type and a T. verrucosum type - and that T, verrucosum is an anamorph of A. benhamiae.