Fred’s new cycling shorts have got special silicone grip strips on the inside of the material to hold the shorts in place. After a day on the saddle, Fred notices that he has got more than just a tan...

Fred’s new cycling shorts have got special silicone grip strips on the inside of the material to hold the shorts in place. After a day on the saddle, Fred notices that he has got more than just a tan line. Two bright red circles appeared on his thighs a few hours after he changed out of his gear. Explain what type of skin condition Fred might be experiencing.