Impetigo is very common in children up to 6 years of age. It also may occur in adults. Those who live in a warm, humid climate are more susceptible to this disease. Insect bites, crowded living conditions, and poor skin cleansing make a person prone to infection. It may spread easily through skin-to-skin contact. Having a weak immune system or a chronic skin problem such as eczema, also increases the chances of contracting impetigo.