Talk to Dermatologist on Skin Desease

Patient 16years. 35kg. i have a strange black circle spot on my neck for years and after some time the same spot appears at my belly area. first i didn't care or notice because it doesn't feel like anything. But as i and my family noticed whenever i take antibiotics syrups Like velosep. It activates and causes me pain,itches,burn, became red. And i asked Ai and showed it pictures of my spot. It says that iam having a fixed drug eruption fron cefixime. And i wanted to confirm. Please tell me about this problem.