By day 5, however, it is perfectly clear that the patients have different diseases. The patient with chickenpox shows several different stages of rash. There are papules, vesicles and pustules present. However, all of the smallpox lesions are at the same stage of development. Most of the chickenpox lesions are small, between 1 and 5 mm, while the smallpox lesions are uniformly larger, between 5 and 10 mm. The smallpox pustules are firm and deeply embedded in the skin while the lesions of chickenpox are much more superficial.