Clinical Characteristics, Symptoms and Burden of Psoriasis and Atopic Dermatitis in Adults

A. Egeberg; C.E.M. Griffiths; H.C. Williams; Y.M.F. Andersen; J.P. Thyssen


The British Journal of Dermatology. 2020;183(1):128-138. 

In This Article

Abstract and Introduction


Background: There is debate as to whether psoriasis and atopic dermatitis (AD ) belong to the same disease spectrum.

Objectives: To describe and compare disease characteristics, lifestyle factors and disease burden in adult patients with psoriasis and AD.

Methods: We linked registry data with clinical and patient-reported outcomes from the Danish Skin Cohort, containing 3348 and 3834 adults with dermatologist-verified psoriasis or AD respectively, and 2946 adults from the general population.

Results: The participants were predominantly women and middle-aged. Patients with psoriasis mostly reported disease onset throughout adulthood, but with a distinct early incidence peak in those with a positive family history or severe disease. AD predominantly began in childhood, with only a very discrete incidence peak in adulthood. Scalp, extremity, chest and abdomen involvement was common to both diseases. Scalp/hairline, elbows, nails, intergluteal cleft, umbilicus, knees and legs were most frequently affected in patients with psoriasis. In AD, periocular, neck, antecubital fossae, back of the hands, interdigital areas and popliteal fossae were commonly affected. Patients with psoriasis (but not AD ) were generally more overweight, obese and physically inactive, and had a positive smoking history, compared with the general population. Patients with both diseases experienced more frequent flares with increasing disease severity. Patients generally displayed uncontrolled disease despite being on systemic therapies. Itch and skin pain were much more severe in patients with AD, whereas joint pain was more common in patients with psoriasis.

Conclusions: We identified important similarities and differences in the clinical characteristics of adults with psoriasis and AD ; these should help clinicians to prioritize and improve patient management.


Psoriasis and atopic dermatitis (AD) are two common chronic skin diseases.[1] With the advent of new therapies to treat psoriasis and AD, the two diseases are increasingly being discussed and presented together in publications and scientific symposia.[2–4] It has even been suggested that psoriasis and AD are part of the same disease spectrum,[5,6] the rationale being the overlap in T-cell-mediated skin and systemic inflammation that responds to cytokine-specific antagonism.

While a unifying and novel disease view may lead to a clearer understanding, it can also mask some of the key differences between psoriasis and AD. Even subtle variations in disease expression and characteristics are important in clinical work, and there is therefore an inherent risk of losing an appreciation of discriminatory differences if the perception of these two skin diseases is reduced to them simply being cutaneous inflammation. This blurring of key differences may in turn negatively affect patient management. Important differences may be obscured in further epidemiological investigations if the two diseases are lumped together.

Very few studies have described and compared the characteristics of adult patients with psoriasis and AD using the same methods.[4,7] Further study may improve the distinction of the two diseases and help to improve overall patient management, for example through better addressing of patient needs, reduction of risk factors and identification of clinically relevant comorbidities. We therefore examined and compared how clinical features were expressed in adults with psoriasis or AD.