This may be a case of acute eczema and the swelling is a sign of inflammation. Along with a moisturiser, topical steroid is required.
Next Steps
Mix the moisturiser with Halonova cream in equal amounts and apply over the swollen sites and patches twice a day ( after bath in the morning and before you sleep at night). Continue with Allegra 180mg twice a day
Health Tips
Do not scratch. That will increase the problem. Also check for
sugar levels.
Apply coconut oil 15 mins before bath daily and use a mild soap like Dove or Pears