Severe muscle loss and pain?

My friend's sister is very sick, but none of the doctors where she lives seem to be able to diagnose her. She lives in Bali. Around two months ago she began drastically losing weight, had no appetite and was lethargic. It progressed to vomiting and high/low body temperatures, headaches, and inability to get to sleep due to severe muscle pain. For the last few weeks, she has been unable to get up/walk/move/eat on her own, she has a rash on her elbows and wrists, and some bruising/pain in her lower back, as well as all-over severe aches over her entire body. She is literally skin and bones now. We don't know what's wrong, she's been tested for different cancers, but the doctors where she is don't seem to have any idea... We're desperate, so any help you can offer would be very appreciated.