Common warts (verruca vulgaris) dermoscopically display multiple densely packed papillae, each containing a central red dot or loop, which is surrounded by a whitish halo. Hemorrhages represent a possible additional feature, appearing as irregularly distributed, small, red to black tiny dots or streaks. Dermoscopy of plantar warts typically reveals multiple prominent hemorrhages within a well-defined, yellowish papilliform surface, in which skin lines are interrupted. This pattern is particularly useful for their discrimination from callus, which lacks blood spots, but instead displays central reddish to bluish structureless pigmentation. Dermoscopy of plane warts typically reveals regularly distributed, tiny, red dots on a light brown to yellow background. These findings allow differentiation from acne or folliculitis, which display a central white to yellow pore corresponding to the comedo or pus within the hair follicle opening.
The dermoscopic pattern of genital warts was initially described as a mosaic pattern consisting of a white reticular network surrounding central small islands of unaffected mucosal skin. More recently, the authors of a study including a large number of patients identified 4 different dermoscopic patterns, which may also coexist in a single wart: unspecific, fingerlike, mosaic and knoblike pattern. Concerning vessels morphology, glomerular, hairpin/dotted, and glomerular/dotted vessels were detected.
Molluscum contagiosum is due to a poxvirus infection and has a characteristic dermoscopic pattern that may facilitate its clinical recognition in selected cases. Dermoscopy is especially useful in detecting the infection before the development of numerous lesions, in pediatric dermatology, or in immunosuppressed patients who may display unusual clinical manifestations. A central pore or umbilication in conjunction with polylobular white to yellow amorphous structures, surrounded by linear or branched vessels (‘red corona’), compose the stereotypic dermoscopic pattern of the disease (Fig 9c).
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