Your husband is probably having insect toxic dermatitis
Tell him to keep hand elevated while sleeping.
Avoid soap bath.
Apply antibiotic cream.
Give him antihistaminics and antibiotics till he fells better.Steroids
may be given in tappering dose for 2 to 3 weeks.
He might be alright.
Still, take him to dermatologist
I hope you got my answer.
Dr. Ilyas Patel MD