If discoloration is raised; then it's probably caused by a pathogen, unless a skin reaction to a chemical substance or a burn. Is the lightbulb or anything hot (i.e. water heater) able to touch frogs skin in enclosure? Have you introduced anything to enclosure lately or handled frog without washing your hands well and rinsing with dechlorinated water? If not; then it appears your frog is sick.
Antibiotics will help if issue is bacterial; but not much if subcutaneous parasites. Also, if a fungi a different medication is required. Sorry; but it's hard to tell just from a picture. Can you please answer the below questions to try and get a better idea of whole situation? Also; what topical non-analgesic antibiotics are available locally? Can you get Melafix and Pimafix at your local pet shop in the fish area section? Thank you

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“Trouble in the Frog Enclosure”
The following information will be very helpful if provided when requesting assistance with either your frog or enclosure. To help with your questions, please utilize the below list and post the information in the proper forum area to get advice from FF members that keep the same frog. This will allow for little confusion and a faster more informed response.
1. Size of enclosure. It's a Eco 60_45-45
2. # of inhabitants - specifically other frogs and size differences one other frog in there a little bigger
3. Humidity. 80%
4. Temperature. around 26
5. Water - type - for both misting and soaking dish rain tank water
6. Materials used for substrate. Glass
7. Enclosure set up i.e. plants (live or artificial), wood, bark and other materials. Artificial plant and driftwood n rock
- How were things prepared prior to being put into the viv.
8. Main food source. Crickets
9. Vitamins and calcium? (how often). Every other feed
10. Lighting. UVB 5watt
11. What is being used to maintain the temperature of the enclosure. Water heater
12. When is the last time he/she ate he ate yesterday
13. Have you found poop lately. Poop fine
14. A pic would be helpful including frog and enclosure (any including cell phone pic is fine). Will try upload more
15. Describe frog's symptoms and/or recent physical changes; to include it's ventral/belly area. No damage just the spot you can see belly is fine
16. How old is the frog I got him a year ago
17. How long have you owned him/her around a year
18. Is the frog wild caught or captive bred unsure bought from pet shop
19. Frog food- how often and if it is diverse, what other feeders are used as treats. None
20. How often the frog is handled. Only occasionally and clean hands.
21. Is the enclosure kept in a high or low traffic area. His is dining area only two people live in my house
22. Describe enclosure maintenance (water changes, cleaning, etc) fortnightly
hope that helps you
by Lynn(Flybyferns) and GrifTheGreat.