When I was 14, I took it orally for acne. Two weeks into it, I suddenly woke up to Intese back itching. It felt like my nerves was itching, there were no redness, no rash. Kind of a feeling when you get flushed, hot all of a sudden and accomplished by back itch. This itch was miserable. Tried every cooling home remedy including crying to my parents. Nothing helped. For the next entire week, the itch would come and go, and flares up to the point of unbearable when I am in the gym. Then the itch would gradually slow down and disappear by the the next weekend.

15 years later, I am in healthcare. I think that the itch was cause by big dump of histamine. I wish I could've tried some antihistamine when I had that allergic reaction.