Passage: Skin chewing can be bolstered by times of apprehension and other unpleasant events. Blisters in particular can cause a feeling of desire to pull or bite off the affected skin and nails (since the skin is dead, thus easily pulled off), which could be detrimental, causing infection. Another disorder, known as excoriation disorder, the repetitive action of uncontrollably picking at one's skin, can sometimes accompany dermatophagia. Dermatophagia differs from excoriation disorder in that the repetitive motion affected persons partake in is the biting of the skin. People who have dermatophagia can also be prone to infection as when they bite their fingers so frequently, they make themselves vulnerable to bacteria seeping in and causing infection. Dermatophagia can be considered a "sister" disorder to trichophagia, which involves compulsively biting and eating one's hair.

Question: What can pulling or biting a blister cause?
infection