Debra:
My best guess is that this is localized eczema. My advice
1. Stop worrying!
2. Stop rubbing!
3. Apply 1% hydrocortisone cream (OTC)
twiceTwice-a-day a day, then cover with moisturizing lotion.
4. Use
BenadrylBenadryl
Benadryl allergy decongestant
Benadryl allergy sinus headache
Benadryl cold cream when it itches.
5. Expect the discoloration to last months before fading.
If this regimen doesn't help, I sugggest you see a dermatologist.
Best.
Dr. Rockoff