Most anything can trigger PTSD-related anxiety, panic attacks, and intrusions. However, this will vary wildly from person to person, and would also have a higher likelihood of affecting those with certain causative stressors over others. This is a very case by case kind of thing. If you, or someone you intend to play with, has PTSD and there is any concern for triggering any such episode, the individual should consult their care provider to assess risk, mitigation, and management techniques.
Intense activities where one feels out of control, especially if not guided through it by a mental health professional, are more likely to trigger such an episode. Tickling, especially on the extreme end, can get deep into the fight or flight aspects of human psyche and behavior.
This is not medical or any other type of professional advice.