By Steven Q. Wang, MD

Eczema and psoriasis are two very common skin conditions affecting more than 42 million Americans. Although the prevalence of both diseases is high, most patients and many physicians do not know the difference between these two skin conditions. As a dermatologist, I often see patients coming into our office who are confused about what they really have. Sometimes, this confusion is due to a misdiagnosis made by other healthcare providers. To make matters worse, patients see many skincare products with labels claiming to help both eczema and psoriasis. The end result is that many patients believe these two skin conditions are the same entity and can be treated with the same skincare products. In this short article, we will highlight two major clinical differences between eczema and psoriasis.

Age of presentation

The age at which each rash presents can be a clue to the right diagnosis. Although psoriasis can appear at any age from infancy to the 8th decade of life, the majority of psoriatic patients have their onset of disease during young adulthood. There are 2 peaks in the age of onset: The first peak is between 20 to 30 years of age, and the 2nd peak is at 50 to 60 years of age.1,2 

In contrast, eczema is a disease associated with an onset early in life. It is estimated that 85% of patients will have eczema before the 1st year of age, and 95% of patients will have the disease present before the age of 5.   It is estimated 10% to 20% of children from the US, Northwest Europe and Asia have eczema. By and large, patients with eczema eventually outgrow their disease when they reach their early to mid-20s. However, there is a small percentage of eczema patients who have very sensitive skin and will be struggling with this condition throughout their entire life.3,4

Clinical presentations

DrWangHero_250NewThere are multiple types of psoriasis. The most common type, i.e. psoriasis vulgaris, usually presents with
sharply demarcated, oval, red, silvery and scaly plaques that are distributed symmetrically throughout the body. The scalp, the elbows and knees are commonly involved. Those lesions can be mildly itchy. When the plaques resolve, the skin can be darker or lighter in color. Nearly 80% of patients will have some sort of nail changes. This is a very important clue to differentiate eczema versus psoriasis.1,2

In contrast, eczema usually involves the flexor surfaces, such as the antecubital fossa, popliteal fossa, the face, neck and extremities. The nose is often spared. Depending on the stages of the disease, eczematous lesions can be very
itchy. Clinically, there are usually red papules and patches with the excoriations. There can also be serous DrWangHero_1110Newcrust and vesicles on these patches. In chronic disease, the skin is often thickened with lichenification, accentuated skin markings, and have a darker skin color.3,4 Nails are not involved.

As a dermatologist, these two simple features often help to differentiate these two common skin conditions.  At times, it may still be a challenge to make the diagnosis, in which case a skin biopsy is often performed to determine the actual diagnosis and initiate the appropriate treatment plan.

 


References

  1. https://www.aad.org/public/diseases/scaly-skin/psoriasis
  2. https://www.psoriasis.org/about-psoriasis
  3. http://www.drwangskincare.com/pages/eczema
  4. https://nationaleczema.org/eczema/

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.