Thanks for the query to H.C.M. Forum.
As you mentioned in your query all these symptoms may be due to .
1 Contact dermatitis
with poisonous material as you mentioned in your query.
Diagnosis can be confirmed with the help of biopsy of the blistering rashes by a dermatologist.
2 Pemphigus vulgaris
may be due to antidermal antibodies
inducing blistering skin disease . Get in blood for c b c & e s r ( if very high may be the cause). Consult a dermatologist
and get his opinion.
this also causes rash ( mild ) with itching and pus formation . Diagnosis can be confirmed by dermatologist with physical examination as well as clinical history.
In my opinion consult a dermatologist and get his help.
Good luck. Dr. HET