Dandruff vs. Psoriasis
Dry, flaky skin on your scalp can be uncomfortable. Those flakes can be caused by dandruff or psoriasis, which are two very different conditions:
- Dandruff (also known as seborrhea), can usually be treated relatively easily and is seldom a serious medical problem.
- Psoriasis, on the other hand, is a chronic condition without a current cure and one that can cause a great deal of discomfort.
Dandruff is a condition marked by flakes of dry skin on the scalp. The flakes can often fall from your hair and land on your shoulders.
Dandruff usually results from a dry scalp. If this is the cause, the flakes are typically small and you may also have dry skin on other parts of your body.
Washing your hair with a harsh shampoo or using a lot of chemicals on your hair can sometimes irritate your scalp and lead to flakes.
A fairly common condition called seborrheic dermatitis is the cause of many dandruff cases. It’s characterized by patches of red and oily skin that leave yellowish flakes on the scalp. These flakes are often larger than the dandruff flakes that can arise from dry skin.
Seborrheic dermatitis can also cause flaky, irritated patches elsewhere on your body, which may lead you to think you have psoriasis.
Unlike dandruff, psoriasis is a problem rooted in your immune system. It’s considered an autoimmune disease, which means special proteins called autoantibodies mistakenly attack healthy tissue.
This attack causes skin cell production to speed up, creating an unhealthy and abnormal growth of new skin that collects in dry, flaky patches on your body, including the scalp.
Normally, dead skin is shed in tiny, thin fragments from the outermost layer of skin. Neither you nor anyone else can ever tell that you’re losing dead skin. New, healthy skin cells are forming beneath the surface of your skin and, in a matter of weeks, rise to the surface to replace the dead skin.
If you have psoriasis, that process speeds up in various spots on your body and there’s no time for the dead skin to go through its normal shedding. That causes dead skin cells to build up on the surface. This usually occurs on the:
- scalp
- elbows
- knees
- back
Psoriasis can take different forms. Sometimes your skin may look cracked and dry. Other times it may be reddened and dotted with small silvery patches.