Inflammatory acne

Inflammatory acne

Papule

A papule occurs when there is a break in the follicular wall. White blood cells rush in and the pore becomes inflamed.

Pustule

A pustule forms several days later when white blood cells make their way to the surface of the skin. This is what people usually refer to as a "zit" or a "pimple".

An inflamed lesion can sometimes completely collapse or explode, severely inflaming the surrounding skin, and sometimes engulfing neighboring follicles. These lesions are called nodules or cysts:

When a follicle breaks along the bottom, total collapse can occur, causing a large, inflamed bump that can be sore to the touch.

Sometimes a severe inflammatory reaction can result in very large pus filled lesions.

Milia

Milia are tiny white bumps that occur when normally sloughed skin cells get trapped in small pockets on the surface of the skin. They are common in newborns across the nose and upper cheeks and can also be seen on adult skin. The bumps disappear as the surface is worn away and the dead skin is sloughed. In newborns, the bumps usually disappear within the first few weeks of life. However, for adults milia may persist indefinitely.

Treatment is usually not indicated in children. Adults can have them removed by a physician for cosmetic improvement.

Read here for complete information on milia.