Are Atopic Dermatitis and Hidradenitis Suppurativa Related?

Atopic dermatitis and hidradenitis suppurativa (HS) are both skin conditions. Atopic dermatitis is the most common type of eczema. Often simply called eczema, it causes dry, itchy, and scaly patches on the skin. HS begins with small, painful lumps under the skin. These lumps can break open or form small tunnels under the skin.^1,2

Even though they both affect the skin, HS and atopic dermatitis have different causes and symptoms. However, researchers now think there may be a link between the conditions.³

Atopic dermatitis versus hidradenitis suppurativa

A 2020 study focused on a potential link between HS and atopic dermatitis. The researchers studied about 7,000 people with HS and a control group of 33,000 people without HS. The goal of the research was to study if having either HS or atopic dermatitis impacts your chances of developing the other condition.³

The researchers found that the people with HS were about twice as likely to develop atopic dermatitis as those in the control group. The researchers also looked at the number of people who had a history of atopic dermatitis. They found that those who had a history of atopic dermatitis were about 40 percent more likely to develop HS.³

What do these findings mean?

This study found a “bidirectional association” between HS and atopic dermatitis. A bidirectional association means that having one of the conditions increases your chances of developing the other one. If this link is proven, it means having either HS or atopic dermatitis could make developing the other condition more likely.⁴

The study also found some factors that were linked to developing both conditions. People with both HS and atopic dermatitis were more likely to be younger women. On average, they also had lower smoking rates and lower body mass index (BMI) levels than people with just HS.³

Limitations of the research

More research is needed to prove a link between HS and atopic dermatitis. This study also has some limitations that can be better researched in the future. This study did not include data on the type or severity of symptoms from HS and atopic dermatitis. This information could make it possible to study more detailed interactions of the conditions.⁴

The study also did not include data on the study participants’ family histories of both conditions. If the people in the study had high numbers of family members with HS or atopic dermatitis, this could help show a genetic link between the conditions.⁴

Impact of this research

This research can increase awareness of a potential link between HS and atopic dermatitis. This knowledge may help dermatologists be aware of the possibility of a person developing a second condition if they already have either one. This may be especially helpful when diagnosing HS if a person has a known history of atopic dermatitis. HS can be hard to diagnose, and early detection can be very important in treating it.^2,4

More research is needed to confirm the link between these conditions. Future studies could also investigate the roll of family history and symptoms on the link. If you have HS or atopic dermatitis and are nervous about developing another condition, talk to your dermatologist. Your dermatologist may be able to provide advice or resources on early detection.⁴