Papular urticaria is a type of red wheal that appears on the body after an allergic reaction, and may be associated with small blisters. It often relates to contact with irritants or insect bites. This condition is not contagious and can be cured in a short time with proper treatment, including the use of anti-allergy medications, although it may recur. Chickenpox is caused by the varicella-zoster virus infection, and is highly contagious, spreading through contact and air between individuals. It generally results in small blisters all over the body, especially on the scalp, and may be accompanied by fever symptoms. Chickenpox usually provides lifelong immunity, meaning that once a person has it, they are unlikely to have it again.