Eczema, Lupus, Urticaria and Psoriasis Top List of AA Comorbidities in Germany

Authors from Germany set out to evaluate the incidence, prevalence and comorbidities associated with alopecia areata. They used claims data from an insurance company and evaluated data between 2016 and 2020. The database included 2.9 million people

In 2020, AA prevalence was calculated to be 210 cases per 100,000 (0.2%) and incidence 72 cases per 100,000 (0.07%). Women were more likely to have AA than men (0.2 % vs. 0.1%). Compared with persons who did not have alopecia areata, patients with AA were more likely to have several disease comorbidities.

MEDICAL CONDITIONS MORE LIKELY IN AA (by FACTOR OF 2-3 FOLD RR)

• atopic dermatitis

• pruritus

• lupus erythematosus

• urticaria

• psoriasis

• ulcerative colitis

• multiple sclerosis

• nail disease

• chronic fatigue syndrome

MEDICAL CONDITIONS MORE LIKELY IN AA (by FACTOR OF 1-2 FOLD RR)

• rheumatoid arthritis,

• thyroid disease,

• allergic rhinitis,

• chronic pancreatitis

• osteoporosis

• migraine

• breast cancer

• hypercholesterolemia

MEDICAL CONDITIONS LESS LIKELY IN AA

• prostate cancer (RR 0.33, 95% CI 0.21−0.53)

MEDICAL CONDITIONS SHOWING NO DIFFERENCE IN AA

• chronic kidney disease, chronic viral hepatitis B, chronic viral hepatitis C, colorectal cancer, fever of other and unknown cause, HIV, leukemia, lung cancer, lymphoma, metabolic disorder (unspecified), myocardial infarction, periodontitis, peripheral arterial occlusive disease of the extremities, renal insufficiency, schizophrenia, ulcer or uveitis.

Comment

This paper captures key epidemiologic information from patients with alopecia areata living in Germany.

The prevalence of AA was estimated at 0.2%, which is lower than the often-quoted statistic of 2%. However, this 2 % statistic seems high when you look at all the studies that have ever been published. It’s interesting that the data comes in at 0.2 %.

Many of the comorbidities identified in this study are consistent with those of other studies. Patients with AA are known to be at risk for atopic dermatitis, lupus, and psoriasis.

Are patients with AA at increased risk for breast cancer?

I was drawn to the data showing that patients in this study had an increased risk of breast cancer.

A 2018 study by Chen et al. also showed an increased risk of breast cancer (as well as lymphoma, kidney and bladder cancer). The Chen et al. study showed that women with alopecia areata under 50 had the highest risk of breast cancer. Not all studies have shown an association between breast cancer and alopecia areata. For example, the 2023 study by George et al. did not.

REFERENCE

Augustin M et al. Epidemiology of alopecia areata and population-wide comorbidities in Germany: analysis of longitudinal claims data. Br J Dermatol . 2024 Feb 16;190(3):374-381. doi: 10.1093/bjd/ljad381.

George P et al. Incidence Rates of Infections, Malignancies, Thromboembolism, and Cardiovascular Events in an Alopecia Areata Cohort from a US Claims Database., Dermatol Ther (Heidelb). 2023 Aug; 13(8): 1733–1746.

Chen C-C et al. Cancer risk in patients with alopecia areata: a nationwide population‐based matched cohort study. Cancer Med. 2018 May; 7(5): 2153–2159. Published online 2018 Mar 25. doi: 10.1002/cam4.1448 PMCID: PMC5943418 PMID: 29577672