pretty good advice. the only thing that's "contagious" or can cause it to spread is the oil from the plant. if you wash the area and get off all the oil (with any kind of soap), some warm water, you'll be good to go and it'll start to heal.
scratching will do nothing so if you want, scratch away. if you have dirty ass fingers it could get infected, but that's just like any other cut or abrasion. hot water generally helps when I get it.
it should take about a week to go away, always person-dependent though (mine stays for like 3 weeks and I scar easily, my skin sucks). if it's really really bad, aka on your face, in between the toes/webs of fingers, on your nuts, you can see your doc and they'll give you low dose steroids.
here's the suggested treatments from my class notes
StartFragment
Treatment:
Remove offending agent
Wet dressing (Burrow’s
solution)
Domboro’s soaks, Aveeno, calamine
Oral anti-histamines
Hydroxyzine 10-25mg hs; Benadryl; Zyrtec
Topical corticosteroids
Oral prednisone/”medrol
dose-pak” for severe cases and/or involving face and eyes
60mg/d then down 10mg/d
-face,
eyelids à prednisone not medrol
dosepak
-medrol
dosepak, suppresses, then usually comes back 3 days later
don’t make it drier, becomes itchier (no sprays, have alcohol which
dries)
EndFragment