Brief Answer:
allergy or fungal rash more likely

Detailed Answer:
HI, thanks for using healthcare magic


The swelling is likely due to the body's inflammatory response to the itching.
Swelling occurs in response to the release of certain chemicals that are secreted in any allergy, infection or trauma

Itchy can be due to infection or allergy (to soap, detergent or any chemical that may have come into contact with this area).
In terms of infection, fungal infections can cause itching.

The options would be to visit your doctor so he or she can take a look and determine which is more likely OR you can consider
(1) using a topical anti fungal cream and a mild topical steroid cream- this would treat both a fungal rash and allergy
The steroid cream should be used for 5 to 7 days only but the fungal cream may need to be continued for up to 2 weeks because fungi respond slowly

Eg of topical steroid over the counter would be hydrocortisone, if a stronger one is needed, you may need a prescription from your doctor

Eg of anti fungals are econazole, ketoconazole, miconazole

(2) use an oral anti histamine to help with the itching, this would also help to reduce the swelling

I hope this helps, feel free to ask any other questions

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