Sneezing, watery eyes, rashes, swelling and itchy skin are symptoms of allergies. The more industrialized a society is, the more allergies its population suffers. They occur because the immune system does not work properly and attacks allergens that enter by the mouth, lungs, cuts on the skin, or other mucosa. Pollen, dust mites, wasp bites and of other insects, and eating certain nuts, are the cause of the most frequent allergic reactions. This infographic from the Ábaco collection is integrated into the Diseases series, which includes the titles: Lung Infections, Bone Degenerations and Diabetes.