Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns....
As per your complain it seems that due to
spider bite there has been
allergic reaction to the toxic substance released by the spider sting under the skin.
It has led to red rash and swelling in the are of bite..
The swollen lump inside the groin can be swollen lymph node secondary to allergic reaction..
I would suggest you to take anti-allergic medication like
Fexofenadine [allegra] or levocetrizine..
Apply a steroid ointment like
Cortisone ointment over the swollen rash area..
Do cool compresses..
Take anti-inflammatory painkiller like
Ibuprofen..
Do alternate cool and warm compresses over the lymph nodes..
In case of no improvement in a week consult an Allergist and get evaluated..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora..