For the past 3 weeks i've been getting cold sores back to back - seems cyclic. taking valtrex (valacyclovir) and lysine. what could be the cause? healthy otherwise.

Stress: Stress levels increasing often can precipate outbreaks of herpetic lesions. If these outbreaks started around the same time as some new stress in your life, then they may be due to the stress hormones in your body suppressing your immune system.

Stress: Your immune system may be stressed from a virus which in turn allows for the herpes virus to cause your cold sores. If you see a dentist that has a laser like the biolase md which can reduce the healing time of the lesions.