This is a type of treatment option for environmental allergies which provides a slow cure overtime versus masking the symptoms.
Please read below for more details:
Chronic spontaneous urticaria is a medical condition when someone develops hives and episodes of swelling which recur frequently and last for over 6 weeks.
It looks like an allergy because the problem is occurring with allergy blood cells called the mast cells. Most often auto-antibodies are made against the mast cells causing them to burst resulting in in itchy hives.
Here is a resource which provides more information on CSU:
https://aacijournal.biomedcentral.com/articles/10.1186/s13223-015-0072-2
Bleach baths cam be used in atopic dermatitis in patients who are prone to skin infections. Please only use this if you have been directed to do so under the direction of your medical doctor. Here is a great resource for the recipe of a bleach bath.