I Am A 54 Year Old Female. For The Past

I am a 54 year old female. For the past five months I've had palmar erythema. It sometimes flares/worsens and occasionally I have joint pain in wrists and hand discomfort with it. I've also had costochondritis during this time and when I sneeze, I often feel the sternum 'cracking' but not always. I've had numerous blood tests and everything from liver to cancer markers have come back completely normal. I've seen a dermatologist who prescribed a topical high strength cortisone cream which I didn't use because the red palms seems to be systemic, not from any external factors. My gynecologist ran more blood tests and determined I am now menopausal. I will be having an endoscopy soon, since I haven't had one in about 10 years. I was diagnosed with an esophageal ulcer 10 years ago and I've taken Prevacid for about a decade. I did wean myself off the PPI last spring and started using blockers like Tagamet, Pepcid and Zantac. I didn't feel that good on those products and unfortunately they never really controlled my heartburn except for when I cut out all things that aggrevated my heartburn, like coffee, bread products, acidic foods, chocolate, etc. No doctor I've seen so far has been able to figure out what's causing the Palmar Erythema. I am somewhat overweight but regularly physically active. I also take Ambien 5mg a night for about 6 months and use a CPAP machine. I'm desperate to figure out what's causing the red palms. I've often wondered if I'm vitamin deficient somehow from taking Prevacid for so many years. My vitamin levels seem to be alright, with a slight deficiency in Vitamin D, for which I'm supplementing. In the last week, I went back on Prevacid because I couldn't tolerate having breakthrough heartburn on the H2 receptor antagonists. When I met with the Gastroenterologist last week to schedule the endoscopy, she suggested alternating Prevacid with Zantac 150 every other day until I could possibly just switch to the Zantac. Perhaps I wasn't using strong enough dosages of the H2 receptor medicines previously. I am questioning whether the Prevacid/H2 blockers are reacting with the Ambien somehow--perhaps they have built up in my system and causing the red palms. I will be attempting to wean off the Ambien soon. I do not have fatty liver, nor any indications of liver disease or cancers. I do not have syphilis. I am an otherwise pretty healthy individual. What kind of endocrine problems can cause Palmar Erythema? It is so frustrating having this problem and I just want to get to the bottom of the cause of the red palms and treat it somehow to have it go away. Please help me! Thank you.