Your friend is lucky to have you looking out for her.
I just did a quick google search for --
lyme weight loss
-- and came up with a lot of interesting links to various sites. I'd suggest you take a quick tour through those. Lyme is known to hijack the endocrine system, messing with hormones and brain function, and therefore with appetite and metabolism.
I gained weight when I was so ill, partly from eating a lot to try to combat the fatigue, but others lose weight. Lyme affects everyone differently, which is part of what makes it so hard to diagnose.
There is a movie called 'Under Our Skin', a documentary made about a few Lyme patients. I'm not wild about the movie, because it goes over the top and is imo intentionally scary to get people's attention. One of the characters in particular (Mandy?) became anorexic and is truly scary to look at. Mission accomplished for the director, but not so good for people who have Lyme and are wondering what is to come next -- the implication is that anorexia happens to everyone. Not.
I would not show your friend that movie, but you might want to view it yourself. It's on DVD and probably available to view online.
fwiw, at the end of the showing of the movie here, the director and some of the people featured in the movie went up on stage to take questions. Introductions were not made as to who these people were, and it was only later that I realized that the healthy-looking blond on stage was the formerly skeletal Mandy. Still skinny, but well and looking normal -- she seems to just be scrawny to start with. But also it could be a co-morbid condition that is or is not connected with the Lyme infection -- only her MD can say.
You are kind to worry about your friend. Lyme can be a very lonely disease, and your companionship means more than you may realize. You may want to have a quiet conversation with her or, maybe better, her family about your concerns and inquire what the MD is saying.
I was once down to 76 pounds because of Lyme Disease. For me, the disease caused my stomach to become so inflammed that anything I ate made me ill or caused pain. I was on intravenous feeding otherwise referred to as TPN and I am now up to 170 pounds! So, to answer your question, yes Lyme Disease can cause weight loss and the anorexia may be secondary to the disease.
Jackie and Ree, thank you SO very much! Your comments are the very first I've ever read that have ever helped me connect the two. On one hand it's somewhat of a relief, on the other, still very upsetting. I think I will finally work up the courage to have a conversation with her family about my concern, and hopefully find out what is going on in terms of treatment. It's all so confusing. If I showed you a photo it would bring you to tears. It's a miracle she is still alive. I will definitely look for that film. And, Ree, congratulations on your recovery! I have hope the same can happen for my friend. Thank you again!
Good for you.
I have read a bit about anorexia (unrelated to something like Lyme) in the past, and it's a difficult thing to approach with someone who has it, because there may already be a psychological component to the ailment, and facing off with them and telling them are being self-destructive can just make them more resistant bec. psychologically driven anorexia is a need to control oneself, including what goes into one's mouth. Very complicated.
I'd tread lightly, and have that quiet conversation with the family rather than confront your friend. Let us know how it goes, okay?