Hi, thanks for your query.
You seem to have developed contact dermatitis
due to poison ivy or something else.
Avoid scratching as it initiates a scratch itch cycle which further aggravates itching. Instead you may take oral anti histamines
Apply a moderate steroid
like momatosone twice a day.
If it does not improve or worsens, you may contact a dermatologist
for exact diagnosis and treatment.
Hope this helps you.