Just started Claravis (Accutane). By the third pill, I experienced reactions. Should I stop?

While allergic reactions to isotretinoin (generic Claravis) is quite rare it can occur. The symptoms you're describing are not consistent with common side effects of isotretinoin but may be a form of intolerance to the medication. The only way to reliably substantiate this is if you stop taking the medication for a short period of time resulting in resolution of the symptoms. I advise consulting with the prescribing dermatologist about your symptoms as they may also be from other causes. However, a trial off the medication should substantiate this as noted above. Good luck!