A Friend I Work With Has Constant Reaccuring Boil Like

a friend i work with has constant reaccuring boil like infections . always more than 1 boil like sores. exteme swelling , heat , and pain. now clustering on back of neck. how contagious? been going on more than 1year. been on antibiotic once . started to clear up until med run out then right back to sores. picks nose constanly, and scratches constanly. help.