Capillaroscopy of the dorsal skin of the hands in hereditary hemorrhagic telangiectasia

Background: Cutaneous telangiectases are manifestations of hereditary hemorrhagic telangiectasia (HHT), a dominantly inherited disorder. Telangiectases have been studied by skin biopsy, and recently by nailfold capillaroscopy. Aim: To confirm the diagnostic role of nailfold capillaroscopy, and assess the value of skin capillaroscopy of the dorsum of the hands in HHT. Design: Prospective clinical investigation. Methods: Using a Wild Heerbrugg-M650 microscope, we studied the nailfolds and dorsum of the hands of 88 patients (37 females, 51 males, mean age 39.7 ± 18.4 years), including 85 with positive genetic testing and three with clinical diagnosis (at least three clinical criteria but a negative genetic test) and 27 controls (13 females, 14 males, mean age 38.6 ± 19.6 years). Results: Microscopic telangiectases were observed on the dorsum of the hands in 80/88 patients (91%): 77 with positive and three with negative genetic tests. No control showed vascular abnormalities. In six patients (7%), nailfold capillaroscopy showed pseudo-megacapillaries and megacapillaries; the remaining 82 (93%) and all controls, had normal capillaroscopic patterns. Discussion: HHT can induce morphological changes in microcirculation that are more easily detectable on the dorsum of the hands than in the nailfold. Microscopic lesions without macroscopic telangiectases were also noted, suggesting the need for further research. Capillaroscopy may provide an additional non-invasive diagnostic criterion for HHT.