Videodermatoscopy enhances the diagnostic capability of palmar and/or plantar psoriasis.

OBJECTIVE: To determine if videodermatoscopy (VD), by evaluation of superficial vascular patterns, may be helpful in the diagnosis of psoriasis in a series of subjects affected by palmar and/or plantar dermatoses with no readily apparent diagnostic features. METHOD: Thirty-two subjects (12 male/20 female, mean age 50 years, range 20-72 years) were sequentially enrolled in an open-label study involving a single visit. Inclusion criteria were the presence of clinically nonspecific, active, and untreated palmar and/or plantar erythematous scaly lesions with no other skin involvement. Exclusion criteria were the presence of co-morbid disorders, excessive hyperkeratosis and/or pustular lesions, and the use of systemic and/or topical drugs within 4 and 2 weeks of study entry, respectively. A videodermatoscope equipped with a zoom lens that allowed magnifications from x50 to x200 was used for vascular pattern evaluation. A skin biopsy for hematoxylin and eosin staining was taken from each patient. RESULTS: In 15 subjects, VD examination at magnification x50 showed the presence of pinpoint-like capillaries linearly arranged along the furrows of dermatoglyphics; at magnification x200, the same capillaries appeared to be dilated and tortuous, with a 'bushy' homogeneous aspect in all examined fields, suggesting a diagnosis of psoriasis, as confirmed by histologic examination. In the remaining 17 subjects, no evidence of 'bushy' capillaries was present at magnification x200 VD examination; in these patients, a diagnosis of eczema was established by histology. CONCLUSION: Although further investigations in larger series are necessary to confirm these findings, and to provide further information about the specificity and sensitivity of the method, our study has indicated that analysis of superficial vascular patterns by VD may represent a promising, non-invasive diagnostic tool in palmar and/or plantar psoriasis.