I Am A 67 Year Old Male Who Has Developed

I am a 67 year old male who has developed fatigue over the last four to five months and recently (within the last month) now small red bumps that have appeared on my neck and chest. The rash comes up as small red raised pimples and then fade into a dark red flat area. No pain. Can you tell me whats going on? BTW I had my Hgb checked and its 14.2.