 [ Symptoms ] dark spots on inside of arm opposite the elbow what is it  the spots are wrinkly and originated after a trip to the beach i thought maybe a jellyfish stung me because there was mild irritation almost a year later the spots have multiplied and darkened what are the possible diagnoses [ Disease ] unless a medical provider could see those spots first hand during an examination it would not be helpful for me to list the hundreds of possibilities that could result in wrinkly spots it would not be prudent to make a blind guess over the internet so i suggest that you see a dermatologist for an examination a year is a long time