Epidemic dropsy is a form of edema of extremities due to poisoning by Argemone mexicana (Mexican prickly poppy). Epidemic dropsy is a clinical state resulting from use of edible oils adulterated with Argemone mexicana seed oil. Sanguinarine and dihydrosanguinarine are two major toxic alkaloids of argemone oil, which cause widespread capillary dilatation, proliferation and increased capillary permeability. When mustard oil is adulterated deliberately (as in most cases) or accidentally with argemone oil, proteinuria (specifically loss of albumin) occurs, with a resultant edema as would occur in nephrotic syndrome. Other major symptoms are bilateral pitting edema of extremities, headache, nausea, loose bowels, erythema, glaucoma and breathlessness. Leakage of the protein-rich plasma component into the extracellular compartment leads to the formation of edema. The haemodynamic consequences of this vascular dilatation and permeability lead to a state of relative hypovolemia with a constant stimulus for fluid and salt conservation by the kidneys. Illness begins with gastroenteric symptoms followed by cutaneous erythema and pigmentation. Respiratory symptoms such as cough, shortness of breath and orthopnoea, progressing to frank right-sided congestive cardiac failure, are seen. Mild to moderate anaemia, hypoproteinaemia, mild to moderate renal azotemia, retinal haemorrhages, and glaucoma are common manifestations. There is no specific therapy. Removal of the adulterated oil and symptomatic treatment of congestive cardiac failure and respiratory symptoms, along with administration of antioxidants and multivitamins, remain the mainstay of treatment. Epidemic dropsy occurs as an epidemic in places where use of mustard oil from the seeds of Brassica juncea, commonly known as Indian mustard, as a cooking medium is common. Signs and symptoms Cause Argemone mexicana Argemone mexicana (family Papaveraceae), a native of West Indies and naturalized in India, is known as “Shailkanta” in Bengal and “Bharbhanda” in Uttar Pradesh. It is also popularly known as “Pivladhatura” or “Satyanashi”, meaning devastating. The plant grows wildly in mustard and other fields. Its seeds are black in colour and are similar to the dark coloured mustards seeds (Brassica juncea) in shape and size. Adulteration of argemone seeds in light yellow colored mustard seeds (Brassica compestris) can easily be detected, but these seeds are rather difficult to visualize when mixed with dark coloured mustard seeds. Argemone seeds yield approximately 35% oil. Alkaloid content in argemone oil varies from 0.44% to 0.50%. Argemone seeds find use as a substitute because of the easy availability, low cost and their complete miscibility of their oil with mustard oil.