What is the difference between lichen planus and atopic dermatitis?

Great question! Though thickened patches of skin may be a common factor between the two, lichen planus is characterized by bumps that are shiny, firm and reddish purple while atopic dermatitis is characterized by dry and scaly patches. Lichen planus can sometimes itch however for atopic dermatitis, itch is one of the most prevalent symptoms. Some more in-depth information on atopic dermatitis (https://atopicdermatitis.net/what-atopic-dermatitis-eczema) and lichen planus here (https://www.aad.org/public/diseases/rashes/lichen-planus#symptoms). Hope this helps!
-Sarah (AtopicDermatitis.net Team Member)