i don't know... i tend to think a lot of skin disorders have similar characteristics but ec is very much its own entity... i got it in my bottom lip immediately after getting a chemical peel to the lips for forcdyde spot removal and i picked the healing skin off a few days early because i was going out to a club... then ec began... i doubt Psoriasis would have that kind of sudden onset simply based on an injury... i will say though, strangely my inner top lip was never peeled and the skin was fine yet ec spread to it about a month after the peel... it's hard for me to make sense of... but i believe that inflammation and this condition can spread throughout the vermillion.
i still don't believe it is psoriasis, or eczema of the lip as it is referred to in medical text, or dermatitis... it's different but shares some similar characteristics.