Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern..
As per your complain sudden itching in elbows and knees followed by appearance of red bumps can be due to either any insect or bug bites leading to
allergic reaction and occurrence of the symptoms..
The chemical released from the sting of organisms have a toxic chemical that can cause allergic reaction and the symptoms that you are experiencing..
I would suggest you to take anti allergics like Levocetrizine or
Benadryl..
You can apply a steroid based cream over the bumps..
You can apply
Calamine lotion to soothe the skin and relieve itching..
Do cool compresses over the bumps to relieve inflammation..
In case if still the symptoms progresses you should consult an Allergist and get evaluated and he can advise injectable
steroids and anti allergics for faster resolution of symptoms along with oral medication..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora..