Managing Atopic Dermatitis in Patients with Comorbidities

Key highlights

Understanding the comorbidities associated with AD is essential for several reasons. Firstly, it helps dermatologists better understand the patient's situation by recognizing associations and possible consequences of the disease. Secondly, it aids in choosing appropriate therapies for individual patients, as biologics and other targeted agents can simultaneously treat multiple conditions. Lastly, it encourages patients to seek help and be screened for comorbidities^1,2.

Article of interest:

Thyssen JP, et al. Comorbidities of atopic dermatitis - what does the evidence say? J Allergy Clin Immunol. 2023 May;151(5):1155-1162.

Atopic Comorbidities

Patients with AD have a significantly increased likelihood of having other atopic diseases (3- to 4-fold increased odds)¹. Furthermore, the atopic comorbidities are part of the diagnostic criteria of AD².

Rhinitis is seen in about 4 out of 10 patients with AD¹. Asthma is present about 2 out of 10 patients, with adults with AD being three times more likely to have asthma than those without AD^1,2. Additionally, food reactions are established as a comorbidity of AD, while nasal polyposis and eosinophilic esophagitis, which share an immunological mechanism with AD, and may also be associated with AD, although the evidence is not certain^1,2.

Biologics like dupilumab can help manage patients with some atopic comorbidities such as asthma, chronic rhinosinusitis with nasal polyposis, and eosinophilic esophagitis³.

Ocular Comorbidities

Ocular comorbidities are also part of the diagnostic criteria for AD. Conjunctivitis is seen in 31.7% of patients with AD, while blepharitis is present in 22% of patients. Less common ocular comorbidities include dry eyes, keratitis, cataract, and keratoconus¹. However, the association between AD and these eye conditions is not well documented and remains uncertain². In some cases, involving an ophthalmologist in patient care is necessary.

Psychiatric Comorbidities

Patients with AD have an increased risk of psychiatric conditions such as depression, anxiety, and suicidal behavior^1,2. Many studies show a two-fold risk of these comorbidities². There is also a possible, but uncertain association between AD and ADHD and autism². The symptoms of AD, particularly itch and lack of sleep, as well as the psychosocial burden of the disease, likely contribute to these psychiatric conditions². Additionally, the increased level of inflammation in AD may directly influence the brain⁴. Some studies indicate that treating AD can improve psychiatric comorbidities^1,2. Using quality of life instruments like the DLQI can help address these issues in patients with AD.

Autoimmune Comorbidities

Alopecia areata is much more common in patients with AD, with probably a ten-fold increase in prevalence¹. JAK inhibitors may be a good treatment option for patients with both AD and alopecia areata^2,5. Vitiligo and urticaria are also more common in patients with AD, with a 1.5 to 2-fold increase in prevalence². Other autoimmune diseases, such as bowel disease, lupus, and rheumatoid arthritis, are probably also more common in patients with AD¹. However, type 1 diabetes is not associated with AD, and some studies suggest a lower risk in patients with AD¹.

Cardiovascular Comorbidities

The relationship between AD and cardiovascular diseases is uncertain and their prevalence possibly only slightly elevated^1,2. Hypertension, coronary artery disease, and peripheral artery disease have a small magnitude of association with AD². Lifestyle factors like smoking and obesity are increased in some studies, but the evidence is low¹. There is a probable but small magnitude of association between thromboembolic disease and AD². This is noteworthy given the possible elevated risk for thromboembolic disease with JAK inhibitors compared to placebo^5-7.

Infectious Comorbidities

Patients with AD have an increased risk of viral (herpes, warts) and bacterial (staphylococcus) infections, likely due to immunological causes and the disrupted skin barrier^1,8. Poorly controlled dermatitis increases the likelihood of infections while targeted therapies that downregulate IL-4 and IL-13 signaling have been associated with improvements in multiple aspects of skin barrier structure and function, including reduction in trans-epidermal water loss, increased levels of barrier function proteins, and normalization of the skin microbiome^2,9,10.

Contact Dermatitis

AD can affect the hands and be complicated by contact dermatitis, most commonly irritant contact dermatitis, but also allergic contact dermatitis. In patients with severe AD, the risk of allergic contact dermatitis is lower, possibly due to immunological reasons. Patch testing can be a relevant work-up in patients with AD.¹

Bone Health Issues

Osteoporosis and fractures are probably increased in patients with AD, possibly due to lifestyle factors (tobacco smoking, physical inactivity) and treatment (especially systemic corticosteroids). Inflammation itself may also contribute^1,2.

Cancer

Patients with AD have an increased risk of skin cancer (keratinocyte cancer), with a 1.3 to 1.5-fold increase in prevalence. This may be due to lower levels of photoprotection in AD, phototherapy, and systemic therapies. There is also a probable slight risk of lymphoma, but no evidence shows associations with other cancers¹. In patients with previous cancers, the use of JAK inhibitors is generally contraindicated^5-7.

Conclusion