Signs and symptoms
In a majority of specific phobias, affected individuals experience heightened anxiety when exposed to a phobic trigger. While BII-phobics experience a similar reaction initially upon exposure, most ultimately respond to a trigger with a biphasic, or two-phase, fainting response. In the first phase, phobics often experience an anxiety reaction characterized by elevated heart rate and heightened blood pressure, as occurs in most other phobias. This is the result of increased activation of the sympathetic nervous system. However, with BII phobia, a second phase usually follows closely, in which the phobic individual experiences a massive dip in heart rate and blood pressure known as vasovagal response. Stimulation of the vagus nerve, a part of the parasympathetic nervous system, is responsible for promoting the lowered heart rate and decreased blood pressure. These physiological changes limit blood flow to the brain and can promote pre-syncope (lightheadedness, feelings of faintness) and syncope (fainting): categorized in this instance as vasovagal fainting. This second, fainting phase is not common to other phobias.A fainting response pattern is not seen in all individuals with BII phobia, but is found in a majority. Up to 80% of those with BII phobia report either syncope or pre-syncope as a symptom when exposed to a trigger.Other symptoms that may evolve when exposed to phobic triggers include extreme chest discomfort, tunnel vision, becoming pale, shock, vertigo, diaphoresis (profuse sweating), nausea, and in very rare cases asystole (cardiac arrest) and death.
Erythrocyanosis crurum is a skin condition, a variant  of acrocyanosis caused by chronic exposure to cold. See also
Chilblains
List of cutaneous conditions

References
Otto Braun-Falco; G. Plewig; H. H. Wolff; Walter H. C. Burgdorf (2000). Dermatology. Springer Verlag. p. 889. ISBN 3-540-59452-3. James, William D.; Berger, Timothy G.;  et al. (2006). Andrews Diseases of the Skin: Clinical Dermatology. Saunders Elsevier. ISBN 0-7216-2921-0. == External links ==