Dandruff, also known as seborrheic dermatitis, tends to occur where the skin is oily or greasy.(1) While the scabs that shed are themselves dry, the underlying incubating environment is one that is very similar to that which produces acne.
There are different levels of dandruff: abnormal greasiness; irritation and itching; scales; secondary infection; and widespread outbreak.(2) Severe sufferers of dandruff may also be prone to parallel outbreaks of acne, though this is the exception rather than the rule.
But whether it be dandruff, acne, or simple oily skin, each is caused by the convergence of a lipophilic yeast organism and a host immune response.(3) The sebum that is secreted as a result by the glands connected to hair follicles is different for each individual. Some people will be prone to heavy outbreaks when dandruff and-or acne occurs. And as people get older, the composition of the sebum also changes.
One way to fight the outbreak of acne and parallel dandruff is to reduce the amount of yeast on a person’s skin. Another method involves altering the composition of that individual’s sebum.
Isotretinoin can be taken to decrease the amount of sebum that a person is producing and change the composition of it as well. These types of medicines basically “starve” the nutritional components of the sebum, causing a chain-link failure down the line to acne cells and other organisms that rely on the sebum activating agents.
On a more basic level, it’s also possible that a severe dandruff sufferer can foment acne if they do not engage in regular hygiene. One of the fundamental ways acne can be caused, regardless of individual sebum, sensitivity, and other factors, is by a clogging of the hair follicles. Flake residue from dandruff, if allowed on a microscopic basis to rest upon a person shoulders, neck, face, and arms, can possible trigger a higher incidence of acne.
(1) National Institutes of Health – Seborrheic Dermatitis, Retrieved July 28, 2011 from http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001959/
(2) St. Mary’s Hospital – Seborrheic Dermatitis and Acne Vulgaris, Retrieved July 28, 2011 from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2070596/?page=1
(3) Parkhurst Exchange – The Link Between Dandruff, Acne, and Oily Skin, Retrieved July 28, 2011 from http://www.parkhurstexchange.com/node/4944?zid=