Question 5.5 from the second paper of 2010 asked for non-cardiac and non-respiratory causes of cyanosis. The following list was concocted using Walker's chapter ("Cyanosis.") in the third edition of Clinical Methods: The History, Physical, and Laboratory Examinations.
- Methylene blue or indocyanine gree dye injection
- Hemosiderosis
- Excess consumption of colloidal silver
- Chronic massive doses of amiodarone
- Chlorpromazine
And, the causes suggested by the college in their model answer:
- Severe methemoglobinemia (though the blood in these cases is supposed to be chocolate brown)
- Sulfhemoglobinemia
- Hemoglobin mutation (eg. Haemoglobin Beth Israel, etc)
- Polycythaemia
- Hypothermia
- High altitude
References
Nagel, Ronald L., et al. "Hemoglobin Beth Israel: A mutant causing clinically apparent cyanosis." New England Journal of Medicine 295.3 (1976): 125-130.
Walker, H. Kenneth, et al. "Cyanosis." in Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition (1990).