Illustration of acute obstructive laryngitis (inflammation of the larynx) caused by diphtheria. This is an infectious disease caused by the bacteria Corynebacterium diphtheriae. Diptheria forms a pseudomembrane (white deposits) that builds up in the throat and nose. This membrane consists of white blood cells, fibrin and dead skin cells. It can cause difficulties with breathing. Diptheria can be treated by using a diphteria antitoxin and antibiotics.