[Single reticulohistiocytoma mimicking a keratoacanthoma].

ascorbic acid levels were measured and found to be noticeably low (<0.1 mg/dL; normal range, 0.2-0.4 mg/dL), thereby confirming the diagnosis. The patient responded extremely well to oral treatment with vitamin C and nutritional supplements of fruits and vegetables; the skin lesions disappeared within 15 days and his overall health improved noticeably. The peculiar pale orange halo observed on dermatoscopy could be explained as the result of the usual changes observed in the violaceous lesions once the extravasated erythrocytes began to be reabsorbed. Such reabsorption might start near the follicle, explaining the presence of the orange halo as a temporary finding within a dynamic process. Against this explanation was the fact that the patient had still not started treatment or experienced clinical improvement as a result. We felt that a correlation between the dermatoscopic image and histopathologic findings was more likely. The perifollicular fibrosis observed in our patient would have rejected or prevented erythrocyte accumulation in the area and both factors (fibrosis and absence of erythrocytes) would explain the pale orange halo mentioned. Beyond the fibrosis area, the dermal collagen would be looser and so allow erythrocytes to accumulate, producing hemorrhagic lesions at the periphery of the pale orange area. We therefore believe that this dermatoscopic observation is not without importance, but could be correlated with the histopathologic findings. If confirmed, the observation could allow chronic and acute scurvy to be distinguished through a clinical sign. There is no reason why acute scurvy would be associated with such a halo, since the perifollicular fibrosis that determines this dermatoscopic sign would not have developed. However, more observations are needed to confirm the validity of this observation.