Fungal skin infection
Since you are already on antibiotics, so the possibility of a fungal infection
is quite high.
You should start application of an antifungal cream like canestan
cream over the affected area twice a day.
Go addition, take some oral antihistamines like benadryl
for the associated itching.
You can also use a clotrimazole
containing dusting powder twice a day over the affected area.
Do not apply any other cream or oil over it.
Wear cotton undergarments so as to reduce sweating since it tends to increase the fungal infections.
Hope it helps
Dr Geetika Paul