Liver specialists at Georgetown University Hospital said Monday that they are treating two additional cases of mushroom poisoning, bringing to four the number of people who have been stricken ill in recent weeks after eating poisonous fungi.

A woman from Warrenton, and her friend visiting from Thailand, picked poisonous mushrooms at a farm near their home and ate them Thursday evening.  Both women got sick the next day. 

One went to a hospital in Leesburg and was transferred to Georgetown on Sunday. The second woman arrived at Georgetown’s emergency department on Sunday and was hospitalized. 

Doctors think the women ate Amanita bisporigera, also known as “Avenging Angel.” These mushrooms are extremely toxic to the liver and sometimes patients who eat them are only saved by having a liver transplant, a hospital spokeswoman said.

Their poisoning comes on the heels of that of Frank Constantinopla, 49, who after a Sept. 12 rainstorm picked mushrooms from his Springfield yard. Constantinopla stir-fried the mushroom with noodles for him and his wife. Both became ill within hours.

Two days later, Constantinopla went to a local emergency room and was transferred to Georgetown University Hospital for a possible liver transplant. He and his wife had eaten Amanita phalloides, a toadstool commonly known as the Death Cap.

About a week later, Walter Lantz Jr., 82, a retired farmer, snacked on mushrooms plucked near his home in Frederick. He ended up at Georgetown University Hospital on Wednesday.

There is no federally approved treatment for mushroom poisoning. All four are being given an experimental drug used to treat poisoning. The intravenous drug made from milk thistle, is called Silibinin, and is being offered through the Georgetown University Medical Center research arm of the Georgetown Transplant Institute.