What Do Itchy Raised Bumps Forming Scab On Skin Mean?

I am asking this question about my husbands problem. He saw a dermatologist for raised bumps that itch and develop a scab. The Dr. gave him a shot of cortisone in buttocks and all the bumps went down and the itching subsided for about 3-4 months. The condition came back even worse after that time frame. We saw another dermatologist and he started treating it with antibiotics and itch cream. He also took a swab and found that he had a slight staff infection. The antibiotics cleared that up. And for a month or so things looked better. Then the swelling of each spot got worse...itching got worse...so cortisone shots were injected to each of the bumps during 2 visits. The bumps went down, but not completely. Dr. keeps telling him to stop itching as the condition will get worse if he doesn t stop. He is due to see the Dr. again this Friday. Yesterday, while sitting one of the little bumps started bleeding and for about 30 sec or a minute we could not get it to stop. I applied pressue to it for about 2 minutes and when I checked it had stopped. But blood was in his shoe, and all over the garage floor where he was sitting. After he showered I applied the antibiotic again...and a few minutes later applied anti-itch. Today so far so good...but the raised bumps are still there and itching is at a minimum. My husband is not diabetic, but does take meds for high blood pressure, cholesterol, thyroid and testosterone. He is 66 yrs. old. The meds the dermatologist has him using are: Clobetasol Propionate CreamUSP, 0.05% when highly inflamed.....2x a day...along with Aurstat anti itch. Dr. has also had him use Triamcinolone Acetonide USP, 0.1%...2 x a day....along with Aurstat anti-itch when sores are better. This condition seems to be hereditary, as a few members of the family have something similar...but definitely not this bad. Suggestions??? Thank you !!!