This could be due to eczema, dermatitis, bacterial or fungal skin
infection, diabetes, some medications, etc.
Keep the area clean and wear clothes washed in a few drops of chlorhexidine preferably and dried in the sun.
You could take oral antihistamine or antiallergic medications for the itching. Apply calamine lotion at the sites. Wear lose comfortable footwear. Maintain good personal hygiene.
You could take over the counter medications for your heartburn.