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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 is usually due to the body’s over reaction to the presence of normal yeast on the skin. This inflammation leads to the overproduction of skin cells, leading to flaking. 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 face and 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.

Dandruff

Dandruff can usually be prevented. Using a dandruff shampoo is often enough to keep dandruff from forming. Keeping your hair clean, in general, is a good idea and washing your hair at least 2 to 3 times a week is ideal.

Oil and dirt can build up on your scalp and cause your scalp to dry. Brushing your hair away from the scalp also helps keep oil from accumulating on your scalp.

Psoriasis

There’s no way to prevent psoriasis. It’s less common in children and often appears between the ages of 15 and 35, but it can develop at any age.

Dandruff

Dandruff can usually be treated with medicated shampoo. It’s also important that you follow the directions of any shampoo you use. Some can be used a couple of times per week, while others can only be used once per week. You may have to switch shampoos, too, as one may become less effective over time.

Psoriasis

Psoriasis can be treated with topical, oral and injectable medications, many of which are steroids, but those only serve to make the symptoms somewhat milder. There’s no actual cure.

Drugs known as disease-modifying antirheumatic drugs (DMARDs) are given to people with moderate to severe psoriasis. Light therapy, which targets psoriasis trouble spots with specially directed ultraviolet light, can also help treat the symptoms of psoriasis.

Biologics can be used to treat various forms of moderate to severe psoriasis. These injectable drugs work by blocking inflammatory proteins.

Often dandruff can be self-diagnosed at home just by observing flakes on your hair and scalp. If you’re concerned it could be something more, a doctor can help identify it as dandruff or psoriasis.

If your doctor believes it may be psoriasis, they’ll ask if you if you’re experiencing other symptoms like joint pain or itchy skin elsewhere on your body.

If your dandruff doesn’t go away or doesn’t get better after 2 weeks of antidandruff shampoo, you may need to see a dermatologist. There are prescription dandruff shampoos that may have the strength you need to overcome the problem. You may also require a medicated topical.

If all signs point to psoriasis, you should also see a dermatologist. If stiff or swollen joints accompany your psoriasis, you may have psoriatic arthritis. A rheumatologist can treat this condition. Your primary care physician should be able to help coordinate your care and your various specialists.