Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern..
As per your complain it seems that your husband has got 
allergic reaction along with chemical injury of the skin with Dettol..
As an immediate 
first aid you should give him anti allergics like Allegra or 
Benadryl..
Do cool compresses over the rashes and swelling..
You can consult an Allergist and get evaluated and he can evaluate you clinically and can give injectable anti allergics and 
steroids to relieve the symptoms soon..
You can also be advised oral anti allergics..
Application of steroid ointment over the rashes can help in reducing inflammation and will relieve burning.
You should continue doing cool compresses..
You can also apply 
Calamine lotion to soothe the skin..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.