▁called ▁" trans ient ". ▁However ▁it ▁may ▁last ▁much ▁longer . ▁Nevertheless , ▁it ▁is ▁not ▁to ▁be ▁confused ▁with ▁rela ps ing ▁linear ▁ac anth ol yt ic ▁der mat osis . ▁ ▁Sign s ▁and ▁sympt oms ▁Gro ver ' s ▁disease ▁often ▁starts ▁quite ▁suddenly . ▁There ▁are ▁intens ely ▁it chy ▁sp ots ▁on ▁the ▁central ▁back , ▁mid ▁ch est ▁and ▁occasionally ▁elsewhere . ▁Fre qu ently , ▁it ▁follows ▁swe ating ▁or ▁some ▁unexpected ▁heat ▁stress . ▁ ▁The ▁it chy ▁er u ption ▁last s ▁an ▁average ▁of ▁ 1 0 – 1 2 ▁months . ▁It ▁is ▁character ized ▁by ▁pap ules ▁and ▁pap ul ov es icles ▁with ▁ex cor i ations ▁occurr ing ▁on ▁the ▁ch est , ▁back , ▁lower ▁stern um , ▁arms , ▁and ▁th igh s . ▁ ▁The ▁pap ules ▁are ▁most ▁commonly ▁found ▁on ▁the ▁mid ▁ch est . ▁ ▁Sometimes ▁the ▁features ▁of ▁Gro ver ' s ▁are ▁found ▁in ▁people ▁who ▁do ▁not ▁it ch ▁or ▁have ▁a ▁consp ic uous ▁r ash . ▁ ▁Most ▁of ▁the ▁people ▁with ▁Gro ver ' s ▁who ▁visit ▁a ▁der mat ologist , ▁however , ▁it ch ▁a ▁lot . ▁ ▁C ause ▁The ▁cause ▁of ▁Gro ver ' s ▁disease ▁is ▁unknown . ▁Sus pected ▁triggers ▁of ▁disease ▁activity ▁include ▁heat ▁and ▁swe ating , ▁sun light , ▁and ▁ad verse ▁reaction ▁to ▁medic ations ▁as ▁well ▁as ▁ion izing ▁radiation , ▁end - stage