Clinicians note that some patients with NF-1 manifest hypersensitivity to cold temperatures. On the other hand I note that there is a preferential localization of NF-1 cutaneous signs in proximity to major arteries and often associated with a higher local temperature.
Preferential sites of melanic pigmented skin spots or patches, neurofibromas and plexiform neurofibromas include the pre-auricular, periocular, lateral neck, peri-axillary, and feet, among other sites. Plexiform neurofibromas are associated with an elevated temperature, hypertrophy of tissues and often with excessive hair growth with altered pigmentation. Some of these points are illustrated in the NF-1 gallery of signs. One hypothesis is that proximity to arteries elevates the local temperature. Perhaps, this is also the basis for café-au-lait spots (CaL) and skin neurofibromas to be less prevalent on the face than on the thorax (usually being warmer than the exposed facial areas). This hypothesis is consonant with investigations showing that neo-capillary-genesis or vasculogenesis is a major component of the pathogenesis of NF-1.
W. Wertelecki, M.D.,